2009-06-22 21:36:29 +08:00
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/*
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2009-11-06 20:52:22 +08:00
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* Synopsys DesignWare I2C adapter driver (master only).
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2009-06-22 21:36:29 +08:00
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*
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* Based on the TI DAVINCI I2C adapter driver.
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*
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* Copyright (C) 2006 Texas Instruments.
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* Copyright (C) 2007 MontaVista Software Inc.
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* Copyright (C) 2009 Provigent Ltd.
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*
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* ----------------------------------------------------------------------------
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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* ----------------------------------------------------------------------------
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*
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*/
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2017-06-14 18:43:21 +08:00
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#include <linux/delay.h>
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2009-06-22 21:36:29 +08:00
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#include <linux/err.h>
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2017-06-14 18:43:23 +08:00
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#include <linux/errno.h>
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#include <linux/export.h>
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2017-11-02 10:40:27 +08:00
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#include <linux/gpio/consumer.h>
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2011-10-29 17:57:23 +08:00
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#include <linux/i2c.h>
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2009-06-22 21:36:29 +08:00
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#include <linux/interrupt.h>
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#include <linux/io.h>
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2013-01-17 18:31:04 +08:00
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#include <linux/module.h>
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2017-06-14 18:43:21 +08:00
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#include <linux/pm_runtime.h>
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2017-11-02 10:40:27 +08:00
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#include <linux/reset.h>
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2009-11-06 20:51:57 +08:00
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2017-06-14 18:43:21 +08:00
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#include "i2c-designware-core.h"
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2011-10-07 02:26:25 +08:00
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2017-06-14 18:43:22 +08:00
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static void i2c_dw_configure_fifo_master(struct dw_i2c_dev *dev)
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{
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/* Configure Tx/Rx FIFO threshold levels */
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dw_writel(dev, dev->tx_fifo_depth / 2, DW_IC_TX_TL);
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dw_writel(dev, 0, DW_IC_RX_TL);
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/* Configure the I2C master */
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dw_writel(dev, dev->master_cfg, DW_IC_CON);
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}
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2009-06-22 21:36:29 +08:00
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/**
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2017-06-14 18:43:21 +08:00
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* i2c_dw_init() - Initialize the designware I2C master hardware
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2009-06-22 21:36:29 +08:00
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* @dev: device private data
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*
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* This functions configures and enables the I2C master.
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* This function is called during I2C init function, and in case of timeout at
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* run time.
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*/
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2017-06-28 22:23:28 +08:00
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static int i2c_dw_init_master(struct dw_i2c_dev *dev)
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2009-06-22 21:36:29 +08:00
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{
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2011-10-07 02:26:32 +08:00
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u32 hcnt, lcnt;
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2016-08-12 22:02:51 +08:00
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u32 reg, comp_param1;
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2014-01-21 00:43:43 +08:00
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u32 sda_falling_time, scl_falling_time;
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2015-01-15 17:12:16 +08:00
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int ret;
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2016-08-24 06:18:54 +08:00
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ret = i2c_dw_acquire_lock(dev);
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if (ret)
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return ret;
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2011-10-07 02:26:28 +08:00
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reg = dw_readl(dev, DW_IC_COMP_TYPE);
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if (reg == ___constant_swab32(DW_IC_COMP_TYPE_VALUE)) {
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2012-04-18 21:01:41 +08:00
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/* Configure register endianess access */
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2017-02-10 18:27:53 +08:00
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dev->flags |= ACCESS_SWAP;
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2012-04-18 21:01:41 +08:00
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} else if (reg == (DW_IC_COMP_TYPE_VALUE & 0x0000ffff)) {
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/* Configure register access mode 16bit */
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2017-02-10 18:27:53 +08:00
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dev->flags |= ACCESS_16BIT;
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2012-04-18 21:01:41 +08:00
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} else if (reg != DW_IC_COMP_TYPE_VALUE) {
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2017-06-14 18:43:21 +08:00
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dev_err(dev->dev,
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"Unknown Synopsys component type: 0x%08x\n", reg);
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2016-08-24 06:18:54 +08:00
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i2c_dw_release_lock(dev);
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2011-10-07 02:26:28 +08:00
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return -ENODEV;
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}
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2009-06-22 21:36:29 +08:00
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2016-08-12 22:02:51 +08:00
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comp_param1 = dw_readl(dev, DW_IC_COMP_PARAM_1);
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2009-06-22 21:36:29 +08:00
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/* Disable the adapter */
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2016-08-24 06:18:53 +08:00
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__i2c_dw_enable_and_wait(dev, false);
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2009-06-22 21:36:29 +08:00
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2017-06-14 18:43:21 +08:00
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/* Set standard and fast speed deviders for high/low periods */
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i2c-designware: Improved _HCNT/_LCNT calculation
* Calculate with accurate conditional expressions from DW manuals.
* Round ic_clk by adding 0.5 as it's important at high ic_clk rate.
* Take into account "tHD;STA" issue for _HCNT calculation.
* Take into account "tf" for _LCNT calculation.
* Add "cond" and "offset" fot further correction requirements.
For _HCNT calculation, there's one issue needs to be carefully
considered; DesignWare I2C core doesn't seem to have solid strategy
to meet the tHD;STA timing spec. If you configure _HCNT based on the
tHIGH timing spec, it easily results in violation of the tHD;STA spec.
After many trials, we came to the conclusion that the tHD;STA period
is proportional to (_HCNT + 3). For the safety's sake, this should be
selected by default.
As for _LCNT calculation, DW I2C core has one characteristic behavior;
he starts counting the SCL CNTs for the LOW period of the SCL clock
(tLOW) as soon as it pulls the SCL line. At that time, he doesn't take
into account the fall time of SCL signal (tf), IOW, he starts counting
CNTs without confirming the SCL input voltage has dropped to below VIL.
This characteristics becomes a problem on some platforms where tf is
considerably long, and results in violation of the tLOW timing spec.
To make the driver configurable as much as possible for various cases,
we'd have separated arguments "tf" and "offset", and for safety default
values should be 0.3 us and 0, respectively.
Signed-off-by: Shinya Kuribayashi <shinya.kuribayashi@necel.com>
Acked-by: Baruch Siach <baruch@tkos.co.il>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
2009-11-06 20:47:01 +08:00
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2014-01-21 00:43:43 +08:00
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sda_falling_time = dev->sda_falling_time ?: 300; /* ns */
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scl_falling_time = dev->scl_falling_time ?: 300; /* ns */
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2015-01-23 17:35:55 +08:00
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/* Set SCL timing parameters for standard-mode */
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2013-08-19 20:07:53 +08:00
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if (dev->ss_hcnt && dev->ss_lcnt) {
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hcnt = dev->ss_hcnt;
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lcnt = dev->ss_lcnt;
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2015-01-23 17:35:55 +08:00
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} else {
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2016-01-04 23:17:35 +08:00
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hcnt = i2c_dw_scl_hcnt(i2c_dw_clk_rate(dev),
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2015-01-23 17:35:55 +08:00
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4000, /* tHD;STA = tHIGH = 4.0 us */
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sda_falling_time,
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0, /* 0: DW default, 1: Ideal */
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0); /* No offset */
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2016-01-04 23:17:35 +08:00
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lcnt = i2c_dw_scl_lcnt(i2c_dw_clk_rate(dev),
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2015-01-23 17:35:55 +08:00
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4700, /* tLOW = 4.7 us */
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scl_falling_time,
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0); /* No offset */
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2013-08-19 20:07:53 +08:00
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}
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2011-10-07 02:26:25 +08:00
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dw_writel(dev, hcnt, DW_IC_SS_SCL_HCNT);
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dw_writel(dev, lcnt, DW_IC_SS_SCL_LCNT);
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i2c-designware: Improved _HCNT/_LCNT calculation
* Calculate with accurate conditional expressions from DW manuals.
* Round ic_clk by adding 0.5 as it's important at high ic_clk rate.
* Take into account "tHD;STA" issue for _HCNT calculation.
* Take into account "tf" for _LCNT calculation.
* Add "cond" and "offset" fot further correction requirements.
For _HCNT calculation, there's one issue needs to be carefully
considered; DesignWare I2C core doesn't seem to have solid strategy
to meet the tHD;STA timing spec. If you configure _HCNT based on the
tHIGH timing spec, it easily results in violation of the tHD;STA spec.
After many trials, we came to the conclusion that the tHD;STA period
is proportional to (_HCNT + 3). For the safety's sake, this should be
selected by default.
As for _LCNT calculation, DW I2C core has one characteristic behavior;
he starts counting the SCL CNTs for the LOW period of the SCL clock
(tLOW) as soon as it pulls the SCL line. At that time, he doesn't take
into account the fall time of SCL signal (tf), IOW, he starts counting
CNTs without confirming the SCL input voltage has dropped to below VIL.
This characteristics becomes a problem on some platforms where tf is
considerably long, and results in violation of the tLOW timing spec.
To make the driver configurable as much as possible for various cases,
we'd have separated arguments "tf" and "offset", and for safety default
values should be 0.3 us and 0, respectively.
Signed-off-by: Shinya Kuribayashi <shinya.kuribayashi@necel.com>
Acked-by: Baruch Siach <baruch@tkos.co.il>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
2009-11-06 20:47:01 +08:00
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dev_dbg(dev->dev, "Standard-mode HCNT:LCNT = %d:%d\n", hcnt, lcnt);
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2016-08-12 22:02:49 +08:00
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/* Set SCL timing parameters for fast-mode or fast-mode plus */
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if ((dev->clk_freq == 1000000) && dev->fp_hcnt && dev->fp_lcnt) {
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hcnt = dev->fp_hcnt;
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lcnt = dev->fp_lcnt;
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} else if (dev->fs_hcnt && dev->fs_lcnt) {
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2013-08-19 20:07:53 +08:00
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hcnt = dev->fs_hcnt;
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lcnt = dev->fs_lcnt;
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2015-01-23 17:35:55 +08:00
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} else {
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2016-01-04 23:17:35 +08:00
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hcnt = i2c_dw_scl_hcnt(i2c_dw_clk_rate(dev),
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2015-01-23 17:35:55 +08:00
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600, /* tHD;STA = tHIGH = 0.6 us */
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sda_falling_time,
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0, /* 0: DW default, 1: Ideal */
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0); /* No offset */
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2016-01-04 23:17:35 +08:00
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lcnt = i2c_dw_scl_lcnt(i2c_dw_clk_rate(dev),
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2015-01-23 17:35:55 +08:00
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1300, /* tLOW = 1.3 us */
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scl_falling_time,
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0); /* No offset */
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2013-08-19 20:07:53 +08:00
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}
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2011-10-07 02:26:25 +08:00
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dw_writel(dev, hcnt, DW_IC_FS_SCL_HCNT);
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dw_writel(dev, lcnt, DW_IC_FS_SCL_LCNT);
|
i2c-designware: Improved _HCNT/_LCNT calculation
* Calculate with accurate conditional expressions from DW manuals.
* Round ic_clk by adding 0.5 as it's important at high ic_clk rate.
* Take into account "tHD;STA" issue for _HCNT calculation.
* Take into account "tf" for _LCNT calculation.
* Add "cond" and "offset" fot further correction requirements.
For _HCNT calculation, there's one issue needs to be carefully
considered; DesignWare I2C core doesn't seem to have solid strategy
to meet the tHD;STA timing spec. If you configure _HCNT based on the
tHIGH timing spec, it easily results in violation of the tHD;STA spec.
After many trials, we came to the conclusion that the tHD;STA period
is proportional to (_HCNT + 3). For the safety's sake, this should be
selected by default.
As for _LCNT calculation, DW I2C core has one characteristic behavior;
he starts counting the SCL CNTs for the LOW period of the SCL clock
(tLOW) as soon as it pulls the SCL line. At that time, he doesn't take
into account the fall time of SCL signal (tf), IOW, he starts counting
CNTs without confirming the SCL input voltage has dropped to below VIL.
This characteristics becomes a problem on some platforms where tf is
considerably long, and results in violation of the tLOW timing spec.
To make the driver configurable as much as possible for various cases,
we'd have separated arguments "tf" and "offset", and for safety default
values should be 0.3 us and 0, respectively.
Signed-off-by: Shinya Kuribayashi <shinya.kuribayashi@necel.com>
Acked-by: Baruch Siach <baruch@tkos.co.il>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
2009-11-06 20:47:01 +08:00
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dev_dbg(dev->dev, "Fast-mode HCNT:LCNT = %d:%d\n", hcnt, lcnt);
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2009-06-22 21:36:29 +08:00
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2016-08-12 22:02:51 +08:00
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if ((dev->master_cfg & DW_IC_CON_SPEED_MASK) ==
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DW_IC_CON_SPEED_HIGH) {
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if ((comp_param1 & DW_IC_COMP_PARAM_1_SPEED_MODE_MASK)
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!= DW_IC_COMP_PARAM_1_SPEED_MODE_HIGH) {
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dev_err(dev->dev, "High Speed not supported!\n");
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dev->master_cfg &= ~DW_IC_CON_SPEED_MASK;
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dev->master_cfg |= DW_IC_CON_SPEED_FAST;
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} else if (dev->hs_hcnt && dev->hs_lcnt) {
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hcnt = dev->hs_hcnt;
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lcnt = dev->hs_lcnt;
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dw_writel(dev, hcnt, DW_IC_HS_SCL_HCNT);
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dw_writel(dev, lcnt, DW_IC_HS_SCL_LCNT);
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dev_dbg(dev->dev, "HighSpeed-mode HCNT:LCNT = %d:%d\n",
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hcnt, lcnt);
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}
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}
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2013-06-26 16:55:06 +08:00
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/* Configure SDA Hold Time if required */
|
i2c: designware: save the preset value of DW_IC_SDA_HOLD
There are several ways to set the SDA hold time for i2c controller,
including: Device Tree, built-in device properties and ACPI. However,
if the SDA hold time is not specified by above method, we should
read the value, where it is preset by firmware, and save it to
sda_hold_time. This is needed because when i2c controller enters
runtime suspend, the DW_IC_SDA_HOLD value will be reset to chipset
default value. And during runtime resume, i2c_dw_init will be called
to reconfigure i2c controller. If sda_hold_time is zero, the chipset
default hold time will be used, that will be too short for some
platforms. Therefore, to have a better tolerance, the DW_IC_SDA_HOLD
value should be kept by sda_hold_time.
Signed-off-by: Zhuo-hao Lee <zhuo-hao.lee@intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2016-08-27 15:39:30 +08:00
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reg = dw_readl(dev, DW_IC_COMP_VERSION);
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if (reg >= DW_IC_SDA_HOLD_MIN_VERS) {
|
2016-09-29 21:04:59 +08:00
|
|
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if (!dev->sda_hold_time) {
|
i2c: designware: save the preset value of DW_IC_SDA_HOLD
There are several ways to set the SDA hold time for i2c controller,
including: Device Tree, built-in device properties and ACPI. However,
if the SDA hold time is not specified by above method, we should
read the value, where it is preset by firmware, and save it to
sda_hold_time. This is needed because when i2c controller enters
runtime suspend, the DW_IC_SDA_HOLD value will be reset to chipset
default value. And during runtime resume, i2c_dw_init will be called
to reconfigure i2c controller. If sda_hold_time is zero, the chipset
default hold time will be used, that will be too short for some
platforms. Therefore, to have a better tolerance, the DW_IC_SDA_HOLD
value should be kept by sda_hold_time.
Signed-off-by: Zhuo-hao Lee <zhuo-hao.lee@intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2016-08-27 15:39:30 +08:00
|
|
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/* Keep previous hold time setting if no one set it */
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dev->sda_hold_time = dw_readl(dev, DW_IC_SDA_HOLD);
|
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}
|
2016-09-29 21:04:59 +08:00
|
|
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/*
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|
|
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* Workaround for avoiding TX arbitration lost in case I2C
|
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* slave pulls SDA down "too quickly" after falling egde of
|
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|
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* SCL by enabling non-zero SDA RX hold. Specification says it
|
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|
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* extends incoming SDA low to high transition while SCL is
|
|
|
|
* high but it apprears to help also above issue.
|
|
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*/
|
|
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if (!(dev->sda_hold_time & DW_IC_SDA_HOLD_RX_MASK))
|
|
|
|
dev->sda_hold_time |= 1 << DW_IC_SDA_HOLD_RX_SHIFT;
|
|
|
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dw_writel(dev, dev->sda_hold_time, DW_IC_SDA_HOLD);
|
2018-03-08 21:23:53 +08:00
|
|
|
} else if (dev->sda_hold_time) {
|
i2c: designware: save the preset value of DW_IC_SDA_HOLD
There are several ways to set the SDA hold time for i2c controller,
including: Device Tree, built-in device properties and ACPI. However,
if the SDA hold time is not specified by above method, we should
read the value, where it is preset by firmware, and save it to
sda_hold_time. This is needed because when i2c controller enters
runtime suspend, the DW_IC_SDA_HOLD value will be reset to chipset
default value. And during runtime resume, i2c_dw_init will be called
to reconfigure i2c controller. If sda_hold_time is zero, the chipset
default hold time will be used, that will be too short for some
platforms. Therefore, to have a better tolerance, the DW_IC_SDA_HOLD
value should be kept by sda_hold_time.
Signed-off-by: Zhuo-hao Lee <zhuo-hao.lee@intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2016-08-27 15:39:30 +08:00
|
|
|
dev_warn(dev->dev,
|
|
|
|
"Hardware too old to adjust SDA hold time.\n");
|
2013-06-26 16:55:06 +08:00
|
|
|
}
|
|
|
|
|
2017-06-14 18:43:22 +08:00
|
|
|
i2c_dw_configure_fifo_master(dev);
|
2016-08-24 06:18:54 +08:00
|
|
|
i2c_dw_release_lock(dev);
|
|
|
|
|
2011-10-07 02:26:28 +08:00
|
|
|
return 0;
|
2009-06-22 21:36:29 +08:00
|
|
|
}
|
|
|
|
|
2009-11-06 20:48:55 +08:00
|
|
|
static void i2c_dw_xfer_init(struct dw_i2c_dev *dev)
|
|
|
|
{
|
|
|
|
struct i2c_msg *msgs = dev->msgs;
|
2017-02-13 17:18:19 +08:00
|
|
|
u32 ic_con, ic_tar = 0;
|
2009-11-06 20:48:55 +08:00
|
|
|
|
2016-11-25 23:22:27 +08:00
|
|
|
/* Disable the adapter */
|
|
|
|
__i2c_dw_enable_and_wait(dev, false);
|
2009-11-06 20:48:55 +08:00
|
|
|
|
2017-06-14 18:43:21 +08:00
|
|
|
/* If the slave address is ten bit address, enable 10BITADDR */
|
2017-02-13 17:18:19 +08:00
|
|
|
ic_con = dw_readl(dev, DW_IC_CON);
|
|
|
|
if (msgs[dev->msg_write_idx].flags & I2C_M_TEN) {
|
|
|
|
ic_con |= DW_IC_CON_10BITADDR_MASTER;
|
2013-09-27 02:57:35 +08:00
|
|
|
/*
|
|
|
|
* If I2C_DYNAMIC_TAR_UPDATE is set, the 10-bit addressing
|
2017-02-13 17:18:19 +08:00
|
|
|
* mode has to be enabled via bit 12 of IC_TAR register.
|
|
|
|
* We set it always as I2C_DYNAMIC_TAR_UPDATE can't be
|
|
|
|
* detected from registers.
|
2013-09-27 02:57:35 +08:00
|
|
|
*/
|
2017-02-13 17:18:19 +08:00
|
|
|
ic_tar = DW_IC_TAR_10BITADDR_MASTER;
|
2013-09-27 02:57:35 +08:00
|
|
|
} else {
|
2017-02-13 17:18:19 +08:00
|
|
|
ic_con &= ~DW_IC_CON_10BITADDR_MASTER;
|
2016-08-24 06:18:55 +08:00
|
|
|
}
|
2009-11-06 20:48:55 +08:00
|
|
|
|
2017-02-13 17:18:19 +08:00
|
|
|
dw_writel(dev, ic_con, DW_IC_CON);
|
|
|
|
|
2013-09-27 02:57:35 +08:00
|
|
|
/*
|
|
|
|
* Set the slave (target) address and enable 10-bit addressing mode
|
|
|
|
* if applicable.
|
|
|
|
*/
|
|
|
|
dw_writel(dev, msgs[dev->msg_write_idx].addr | ic_tar, DW_IC_TAR);
|
|
|
|
|
2017-06-14 18:43:21 +08:00
|
|
|
/* Enforce disabled interrupts (due to HW issues) */
|
2014-04-11 07:03:19 +08:00
|
|
|
i2c_dw_disable_int(dev);
|
|
|
|
|
2016-11-25 23:22:27 +08:00
|
|
|
/* Enable the adapter */
|
2018-04-28 21:56:06 +08:00
|
|
|
__i2c_dw_enable(dev, true);
|
|
|
|
|
|
|
|
/* Dummy read to avoid the register getting stuck on Bay Trail */
|
|
|
|
dw_readl(dev, DW_IC_ENABLE_STATUS);
|
2009-11-06 20:50:40 +08:00
|
|
|
|
2013-05-13 08:54:30 +08:00
|
|
|
/* Clear and enable interrupts */
|
2015-08-31 22:31:28 +08:00
|
|
|
dw_readl(dev, DW_IC_CLR_INTR);
|
2017-06-14 18:43:22 +08:00
|
|
|
dw_writel(dev, DW_IC_INTR_MASTER_MASK, DW_IC_INTR_MASK);
|
2009-11-06 20:48:55 +08:00
|
|
|
}
|
|
|
|
|
2009-06-22 21:36:29 +08:00
|
|
|
/*
|
2009-11-06 20:50:40 +08:00
|
|
|
* Initiate (and continue) low level master read/write transaction.
|
|
|
|
* This function is only called from i2c_dw_isr, and pumping i2c_msg
|
|
|
|
* messages into the tx buffer. Even if the size of i2c_msg data is
|
|
|
|
* longer than the size of the tx buffer, it handles everything.
|
2009-06-22 21:36:29 +08:00
|
|
|
*/
|
2012-10-06 04:23:53 +08:00
|
|
|
static void
|
2009-11-06 20:46:04 +08:00
|
|
|
i2c_dw_xfer_msg(struct dw_i2c_dev *dev)
|
2009-06-22 21:36:29 +08:00
|
|
|
{
|
|
|
|
struct i2c_msg *msgs = dev->msgs;
|
2009-11-06 20:48:55 +08:00
|
|
|
u32 intr_mask;
|
2009-11-06 20:49:39 +08:00
|
|
|
int tx_limit, rx_limit;
|
2009-11-06 20:43:52 +08:00
|
|
|
u32 addr = msgs[dev->msg_write_idx].addr;
|
|
|
|
u32 buf_len = dev->tx_buf_len;
|
2011-07-27 14:06:29 +08:00
|
|
|
u8 *buf = dev->tx_buf;
|
2013-06-21 15:05:28 +08:00
|
|
|
bool need_restart = false;
|
2009-06-22 21:36:29 +08:00
|
|
|
|
2017-06-14 18:43:22 +08:00
|
|
|
intr_mask = DW_IC_INTR_MASTER_MASK;
|
2009-11-06 20:47:30 +08:00
|
|
|
|
2009-11-06 20:46:29 +08:00
|
|
|
for (; dev->msg_write_idx < dev->msgs_num; dev->msg_write_idx++) {
|
2016-11-10 10:56:33 +08:00
|
|
|
u32 flags = msgs[dev->msg_write_idx].flags;
|
|
|
|
|
2009-11-06 20:52:22 +08:00
|
|
|
/*
|
2017-06-14 18:43:21 +08:00
|
|
|
* If target address has changed, we need to
|
|
|
|
* reprogram the target address in the I2C
|
|
|
|
* adapter when we are done with this transfer.
|
2009-06-22 21:36:29 +08:00
|
|
|
*/
|
2009-11-06 20:51:18 +08:00
|
|
|
if (msgs[dev->msg_write_idx].addr != addr) {
|
|
|
|
dev_err(dev->dev,
|
|
|
|
"%s: invalid target address\n", __func__);
|
|
|
|
dev->msg_err = -EINVAL;
|
|
|
|
break;
|
|
|
|
}
|
2009-06-22 21:36:29 +08:00
|
|
|
|
|
|
|
if (msgs[dev->msg_write_idx].len == 0) {
|
|
|
|
dev_err(dev->dev,
|
|
|
|
"%s: invalid message length\n", __func__);
|
|
|
|
dev->msg_err = -EINVAL;
|
2009-11-06 20:51:18 +08:00
|
|
|
break;
|
2009-06-22 21:36:29 +08:00
|
|
|
}
|
|
|
|
|
|
|
|
if (!(dev->status & STATUS_WRITE_IN_PROGRESS)) {
|
|
|
|
/* new i2c_msg */
|
2009-11-06 20:49:14 +08:00
|
|
|
buf = msgs[dev->msg_write_idx].buf;
|
2009-06-22 21:36:29 +08:00
|
|
|
buf_len = msgs[dev->msg_write_idx].len;
|
2013-06-21 15:05:28 +08:00
|
|
|
|
|
|
|
/* If both IC_EMPTYFIFO_HOLD_MASTER_EN and
|
|
|
|
* IC_RESTART_EN are set, we must manually
|
|
|
|
* set restart bit between messages.
|
|
|
|
*/
|
|
|
|
if ((dev->master_cfg & DW_IC_CON_RESTART_EN) &&
|
|
|
|
(dev->msg_write_idx > 0))
|
|
|
|
need_restart = true;
|
2009-06-22 21:36:29 +08:00
|
|
|
}
|
|
|
|
|
2011-10-07 02:26:25 +08:00
|
|
|
tx_limit = dev->tx_fifo_depth - dw_readl(dev, DW_IC_TXFLR);
|
|
|
|
rx_limit = dev->rx_fifo_depth - dw_readl(dev, DW_IC_RXFLR);
|
2009-11-06 20:49:39 +08:00
|
|
|
|
2009-06-22 21:36:29 +08:00
|
|
|
while (buf_len > 0 && tx_limit > 0 && rx_limit > 0) {
|
2013-01-17 18:31:05 +08:00
|
|
|
u32 cmd = 0;
|
|
|
|
|
|
|
|
/*
|
|
|
|
* If IC_EMPTYFIFO_HOLD_MASTER_EN is set we must
|
|
|
|
* manually set the stop bit. However, it cannot be
|
|
|
|
* detected from the registers so we set it always
|
|
|
|
* when writing/reading the last byte.
|
|
|
|
*/
|
2016-11-10 10:56:33 +08:00
|
|
|
|
|
|
|
/*
|
2017-05-23 17:08:04 +08:00
|
|
|
* i2c-core always sets the buffer length of
|
2016-11-10 10:56:33 +08:00
|
|
|
* I2C_FUNC_SMBUS_BLOCK_DATA to 1. The length will
|
|
|
|
* be adjusted when receiving the first byte.
|
|
|
|
* Thus we can't stop the transaction here.
|
|
|
|
*/
|
2013-01-17 18:31:05 +08:00
|
|
|
if (dev->msg_write_idx == dev->msgs_num - 1 &&
|
2016-11-10 10:56:33 +08:00
|
|
|
buf_len == 1 && !(flags & I2C_M_RECV_LEN))
|
2013-01-17 18:31:05 +08:00
|
|
|
cmd |= BIT(9);
|
|
|
|
|
2013-06-21 15:05:28 +08:00
|
|
|
if (need_restart) {
|
|
|
|
cmd |= BIT(10);
|
|
|
|
need_restart = false;
|
|
|
|
}
|
|
|
|
|
2009-06-22 21:36:29 +08:00
|
|
|
if (msgs[dev->msg_write_idx].flags & I2C_M_RD) {
|
2013-04-20 00:28:10 +08:00
|
|
|
|
2017-06-14 18:43:21 +08:00
|
|
|
/* Avoid rx buffer overrun */
|
i2c: designware: fix rx fifo depth tracking
When loading the TX fifo to receive bytes on the I2C bus, we incorrectly
count the number of bytes:
rx_limit = dev->rx_fifo_depth - dw_readl(dev, DW_IC_RXFLR);
while (buf_len > 0 && tx_limit > 0 && rx_limit > 0) {
if (rx_limit - dev->rx_outstanding <= 0)
break;
rx_limit--;
dev->rx_outstanding++;
}
DW_IC_RXFLR indicates how many bytes are available to be read in the
FIFO, dev->rx_fifo_depth is the FIFO size, and dev->rx_outstanding is
the number of bytes that we've requested to be read so far, but which
have not been read.
Firstly, increasing dev->rx_outstanding and decreasing rx_limit and then
comparing them results in each byte consuming "two" bytes in this
tracking, so this is obviously wrong.
Secondly, the number of bytes that _could_ be received into the FIFO at
any time is the number of bytes we have so far requested but not yet
read from the FIFO - in other words dev->rx_outstanding.
So, in order to request enough bytes to fill the RX FIFO, we need to
request dev->rx_fifo_depth - dev->rx_outstanding bytes.
Modifying the code thusly results in us reaching the maximum number of
bytes outstanding each time we queue more "receive" operations, provided
the transfer allows that to happen.
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Acked-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2016-11-19 03:40:10 +08:00
|
|
|
if (dev->rx_outstanding >= dev->rx_fifo_depth)
|
2013-04-20 00:28:10 +08:00
|
|
|
break;
|
|
|
|
|
2013-01-17 18:31:05 +08:00
|
|
|
dw_writel(dev, cmd | 0x100, DW_IC_DATA_CMD);
|
2009-06-22 21:36:29 +08:00
|
|
|
rx_limit--;
|
2013-04-20 00:28:10 +08:00
|
|
|
dev->rx_outstanding++;
|
2009-06-22 21:36:29 +08:00
|
|
|
} else
|
2013-01-17 18:31:05 +08:00
|
|
|
dw_writel(dev, cmd | *buf++, DW_IC_DATA_CMD);
|
2009-06-22 21:36:29 +08:00
|
|
|
tx_limit--; buf_len--;
|
|
|
|
}
|
2009-11-06 20:47:30 +08:00
|
|
|
|
2009-11-06 20:49:14 +08:00
|
|
|
dev->tx_buf = buf;
|
2009-11-06 20:47:30 +08:00
|
|
|
dev->tx_buf_len = buf_len;
|
|
|
|
|
2016-11-10 10:56:33 +08:00
|
|
|
/*
|
|
|
|
* Because we don't know the buffer length in the
|
|
|
|
* I2C_FUNC_SMBUS_BLOCK_DATA case, we can't stop
|
|
|
|
* the transaction here.
|
|
|
|
*/
|
|
|
|
if (buf_len > 0 || flags & I2C_M_RECV_LEN) {
|
2009-11-06 20:47:30 +08:00
|
|
|
/* more bytes to be written */
|
|
|
|
dev->status |= STATUS_WRITE_IN_PROGRESS;
|
|
|
|
break;
|
2009-11-06 20:51:00 +08:00
|
|
|
} else
|
2009-11-06 20:47:30 +08:00
|
|
|
dev->status &= ~STATUS_WRITE_IN_PROGRESS;
|
2009-06-22 21:36:29 +08:00
|
|
|
}
|
|
|
|
|
2009-11-06 20:51:00 +08:00
|
|
|
/*
|
|
|
|
* If i2c_msg index search is completed, we don't need TX_EMPTY
|
|
|
|
* interrupt any more.
|
|
|
|
*/
|
|
|
|
if (dev->msg_write_idx == dev->msgs_num)
|
|
|
|
intr_mask &= ~DW_IC_INTR_TX_EMPTY;
|
|
|
|
|
2009-11-06 20:51:18 +08:00
|
|
|
if (dev->msg_err)
|
|
|
|
intr_mask = 0;
|
|
|
|
|
2011-10-29 17:57:23 +08:00
|
|
|
dw_writel(dev, intr_mask, DW_IC_INTR_MASK);
|
2009-06-22 21:36:29 +08:00
|
|
|
}
|
|
|
|
|
2016-11-10 10:56:33 +08:00
|
|
|
static u8
|
|
|
|
i2c_dw_recv_len(struct dw_i2c_dev *dev, u8 len)
|
|
|
|
{
|
|
|
|
struct i2c_msg *msgs = dev->msgs;
|
|
|
|
u32 flags = msgs[dev->msg_read_idx].flags;
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Adjust the buffer length and mask the flag
|
|
|
|
* after receiving the first byte.
|
|
|
|
*/
|
|
|
|
len += (flags & I2C_CLIENT_PEC) ? 2 : 1;
|
|
|
|
dev->tx_buf_len = len - min_t(u8, len, dev->rx_outstanding);
|
|
|
|
msgs[dev->msg_read_idx].len = len;
|
|
|
|
msgs[dev->msg_read_idx].flags &= ~I2C_M_RECV_LEN;
|
|
|
|
|
|
|
|
return len;
|
|
|
|
}
|
|
|
|
|
2009-06-22 21:36:29 +08:00
|
|
|
static void
|
2009-11-06 20:45:39 +08:00
|
|
|
i2c_dw_read(struct dw_i2c_dev *dev)
|
2009-06-22 21:36:29 +08:00
|
|
|
{
|
|
|
|
struct i2c_msg *msgs = dev->msgs;
|
2009-11-06 20:49:39 +08:00
|
|
|
int rx_valid;
|
2009-06-22 21:36:29 +08:00
|
|
|
|
2009-11-06 20:46:29 +08:00
|
|
|
for (; dev->msg_read_idx < dev->msgs_num; dev->msg_read_idx++) {
|
2009-11-06 20:43:52 +08:00
|
|
|
u32 len;
|
2009-06-22 21:36:29 +08:00
|
|
|
u8 *buf;
|
|
|
|
|
|
|
|
if (!(msgs[dev->msg_read_idx].flags & I2C_M_RD))
|
|
|
|
continue;
|
|
|
|
|
|
|
|
if (!(dev->status & STATUS_READ_IN_PROGRESS)) {
|
|
|
|
len = msgs[dev->msg_read_idx].len;
|
|
|
|
buf = msgs[dev->msg_read_idx].buf;
|
|
|
|
} else {
|
|
|
|
len = dev->rx_buf_len;
|
|
|
|
buf = dev->rx_buf;
|
|
|
|
}
|
|
|
|
|
2011-10-07 02:26:25 +08:00
|
|
|
rx_valid = dw_readl(dev, DW_IC_RXFLR);
|
2009-11-06 20:49:39 +08:00
|
|
|
|
2013-04-20 00:28:10 +08:00
|
|
|
for (; len > 0 && rx_valid > 0; len--, rx_valid--) {
|
2016-11-10 10:56:33 +08:00
|
|
|
u32 flags = msgs[dev->msg_read_idx].flags;
|
|
|
|
|
|
|
|
*buf = dw_readl(dev, DW_IC_DATA_CMD);
|
|
|
|
/* Ensure length byte is a valid value */
|
|
|
|
if (flags & I2C_M_RECV_LEN &&
|
|
|
|
*buf <= I2C_SMBUS_BLOCK_MAX && *buf > 0) {
|
|
|
|
len = i2c_dw_recv_len(dev, *buf);
|
|
|
|
}
|
|
|
|
buf++;
|
2013-04-20 00:28:10 +08:00
|
|
|
dev->rx_outstanding--;
|
|
|
|
}
|
2009-06-22 21:36:29 +08:00
|
|
|
|
|
|
|
if (len > 0) {
|
|
|
|
dev->status |= STATUS_READ_IN_PROGRESS;
|
|
|
|
dev->rx_buf_len = len;
|
|
|
|
dev->rx_buf = buf;
|
|
|
|
return;
|
|
|
|
} else
|
|
|
|
dev->status &= ~STATUS_READ_IN_PROGRESS;
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
|
|
|
/*
|
2017-06-14 18:43:21 +08:00
|
|
|
* Prepare controller for a transaction and call i2c_dw_xfer_msg.
|
2009-06-22 21:36:29 +08:00
|
|
|
*/
|
2015-10-12 21:55:35 +08:00
|
|
|
static int
|
2009-06-22 21:36:29 +08:00
|
|
|
i2c_dw_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)
|
|
|
|
{
|
|
|
|
struct dw_i2c_dev *dev = i2c_get_adapdata(adap);
|
|
|
|
int ret;
|
|
|
|
|
|
|
|
dev_dbg(dev->dev, "%s: msgs: %d\n", __func__, num);
|
|
|
|
|
2011-10-07 02:26:36 +08:00
|
|
|
pm_runtime_get_sync(dev->dev);
|
2009-06-22 21:36:29 +08:00
|
|
|
|
2013-11-15 06:32:02 +08:00
|
|
|
reinit_completion(&dev->cmd_complete);
|
2009-06-22 21:36:29 +08:00
|
|
|
dev->msgs = msgs;
|
|
|
|
dev->msgs_num = num;
|
|
|
|
dev->cmd_err = 0;
|
|
|
|
dev->msg_write_idx = 0;
|
|
|
|
dev->msg_read_idx = 0;
|
|
|
|
dev->msg_err = 0;
|
|
|
|
dev->status = STATUS_IDLE;
|
2009-11-06 20:51:57 +08:00
|
|
|
dev->abort_source = 0;
|
2013-04-20 00:28:10 +08:00
|
|
|
dev->rx_outstanding = 0;
|
2009-06-22 21:36:29 +08:00
|
|
|
|
2016-08-24 06:18:54 +08:00
|
|
|
ret = i2c_dw_acquire_lock(dev);
|
|
|
|
if (ret)
|
|
|
|
goto done_nolock;
|
2015-01-15 17:12:16 +08:00
|
|
|
|
2009-06-22 21:36:29 +08:00
|
|
|
ret = i2c_dw_wait_bus_not_busy(dev);
|
|
|
|
if (ret < 0)
|
|
|
|
goto done;
|
|
|
|
|
2017-06-14 18:43:21 +08:00
|
|
|
/* Start the transfers */
|
2009-11-06 20:48:55 +08:00
|
|
|
i2c_dw_xfer_init(dev);
|
2009-06-22 21:36:29 +08:00
|
|
|
|
2017-06-14 18:43:21 +08:00
|
|
|
/* Wait for tx to complete */
|
2016-06-17 09:46:35 +08:00
|
|
|
if (!wait_for_completion_timeout(&dev->cmd_complete, adap->timeout)) {
|
2009-06-22 21:36:29 +08:00
|
|
|
dev_err(dev->dev, "controller timed out\n");
|
2013-06-07 16:51:23 +08:00
|
|
|
/* i2c_dw_init implicitly disables the adapter */
|
2017-11-02 10:40:27 +08:00
|
|
|
i2c_recover_bus(&dev->adapter);
|
2017-06-28 22:23:28 +08:00
|
|
|
i2c_dw_init_master(dev);
|
2009-06-22 21:36:29 +08:00
|
|
|
ret = -ETIMEDOUT;
|
|
|
|
goto done;
|
2013-05-22 18:03:11 +08:00
|
|
|
}
|
2009-06-22 21:36:29 +08:00
|
|
|
|
2016-11-25 23:22:27 +08:00
|
|
|
/*
|
|
|
|
* We must disable the adapter before returning and signaling the end
|
|
|
|
* of the current transfer. Otherwise the hardware might continue
|
|
|
|
* generating interrupts which in turn causes a race condition with
|
|
|
|
* the following transfer. Needs some more investigation if the
|
|
|
|
* additional interrupts are a hardware bug or this driver doesn't
|
|
|
|
* handle them correctly yet.
|
|
|
|
*/
|
|
|
|
__i2c_dw_enable(dev, false);
|
|
|
|
|
2009-06-22 21:36:29 +08:00
|
|
|
if (dev->msg_err) {
|
|
|
|
ret = dev->msg_err;
|
|
|
|
goto done;
|
|
|
|
}
|
|
|
|
|
2017-06-14 18:43:21 +08:00
|
|
|
/* No error */
|
2016-11-19 03:40:04 +08:00
|
|
|
if (likely(!dev->cmd_err && !dev->status)) {
|
2009-06-22 21:36:29 +08:00
|
|
|
ret = num;
|
|
|
|
goto done;
|
|
|
|
}
|
|
|
|
|
|
|
|
/* We have an error */
|
|
|
|
if (dev->cmd_err == DW_IC_ERR_TX_ABRT) {
|
2009-11-06 20:51:57 +08:00
|
|
|
ret = i2c_dw_handle_tx_abort(dev);
|
|
|
|
goto done;
|
2009-06-22 21:36:29 +08:00
|
|
|
}
|
2016-11-19 03:40:04 +08:00
|
|
|
|
|
|
|
if (dev->status)
|
|
|
|
dev_err(dev->dev,
|
|
|
|
"transfer terminated early - interrupt latency too high?\n");
|
|
|
|
|
2009-06-22 21:36:29 +08:00
|
|
|
ret = -EIO;
|
|
|
|
|
|
|
|
done:
|
2016-08-24 06:18:54 +08:00
|
|
|
i2c_dw_release_lock(dev);
|
2015-01-15 17:12:16 +08:00
|
|
|
|
|
|
|
done_nolock:
|
2013-04-10 08:36:42 +08:00
|
|
|
pm_runtime_mark_last_busy(dev->dev);
|
|
|
|
pm_runtime_put_autosuspend(dev->dev);
|
2009-06-22 21:36:29 +08:00
|
|
|
|
|
|
|
return ret;
|
|
|
|
}
|
|
|
|
|
2017-01-28 02:06:17 +08:00
|
|
|
static const struct i2c_algorithm i2c_dw_algo = {
|
2017-06-14 18:43:21 +08:00
|
|
|
.master_xfer = i2c_dw_xfer,
|
|
|
|
.functionality = i2c_dw_func,
|
2015-10-12 21:55:35 +08:00
|
|
|
};
|
2009-06-22 21:36:29 +08:00
|
|
|
|
2009-11-06 20:44:37 +08:00
|
|
|
static u32 i2c_dw_read_clear_intrbits(struct dw_i2c_dev *dev)
|
|
|
|
{
|
|
|
|
u32 stat;
|
|
|
|
|
|
|
|
/*
|
|
|
|
* The IC_INTR_STAT register just indicates "enabled" interrupts.
|
|
|
|
* Ths unmasked raw version of interrupt status bits are available
|
|
|
|
* in the IC_RAW_INTR_STAT register.
|
|
|
|
*
|
|
|
|
* That is,
|
2011-10-29 17:57:23 +08:00
|
|
|
* stat = dw_readl(IC_INTR_STAT);
|
2009-11-06 20:44:37 +08:00
|
|
|
* equals to,
|
2011-10-29 17:57:23 +08:00
|
|
|
* stat = dw_readl(IC_RAW_INTR_STAT) & dw_readl(IC_INTR_MASK);
|
2009-11-06 20:44:37 +08:00
|
|
|
*
|
|
|
|
* The raw version might be useful for debugging purposes.
|
|
|
|
*/
|
2011-10-07 02:26:25 +08:00
|
|
|
stat = dw_readl(dev, DW_IC_INTR_STAT);
|
2009-11-06 20:44:37 +08:00
|
|
|
|
|
|
|
/*
|
|
|
|
* Do not use the IC_CLR_INTR register to clear interrupts, or
|
|
|
|
* you'll miss some interrupts, triggered during the period from
|
2011-10-29 17:57:23 +08:00
|
|
|
* dw_readl(IC_INTR_STAT) to dw_readl(IC_CLR_INTR).
|
2009-11-06 20:44:37 +08:00
|
|
|
*
|
|
|
|
* Instead, use the separately-prepared IC_CLR_* registers.
|
|
|
|
*/
|
|
|
|
if (stat & DW_IC_INTR_RX_UNDER)
|
2011-10-07 02:26:25 +08:00
|
|
|
dw_readl(dev, DW_IC_CLR_RX_UNDER);
|
2009-11-06 20:44:37 +08:00
|
|
|
if (stat & DW_IC_INTR_RX_OVER)
|
2011-10-07 02:26:25 +08:00
|
|
|
dw_readl(dev, DW_IC_CLR_RX_OVER);
|
2009-11-06 20:44:37 +08:00
|
|
|
if (stat & DW_IC_INTR_TX_OVER)
|
2011-10-07 02:26:25 +08:00
|
|
|
dw_readl(dev, DW_IC_CLR_TX_OVER);
|
2009-11-06 20:44:37 +08:00
|
|
|
if (stat & DW_IC_INTR_RD_REQ)
|
2011-10-07 02:26:25 +08:00
|
|
|
dw_readl(dev, DW_IC_CLR_RD_REQ);
|
2009-11-06 20:44:37 +08:00
|
|
|
if (stat & DW_IC_INTR_TX_ABRT) {
|
|
|
|
/*
|
|
|
|
* The IC_TX_ABRT_SOURCE register is cleared whenever
|
|
|
|
* the IC_CLR_TX_ABRT is read. Preserve it beforehand.
|
|
|
|
*/
|
2011-10-07 02:26:25 +08:00
|
|
|
dev->abort_source = dw_readl(dev, DW_IC_TX_ABRT_SOURCE);
|
|
|
|
dw_readl(dev, DW_IC_CLR_TX_ABRT);
|
2009-11-06 20:44:37 +08:00
|
|
|
}
|
|
|
|
if (stat & DW_IC_INTR_RX_DONE)
|
2011-10-07 02:26:25 +08:00
|
|
|
dw_readl(dev, DW_IC_CLR_RX_DONE);
|
2009-11-06 20:44:37 +08:00
|
|
|
if (stat & DW_IC_INTR_ACTIVITY)
|
2011-10-07 02:26:25 +08:00
|
|
|
dw_readl(dev, DW_IC_CLR_ACTIVITY);
|
2009-11-06 20:44:37 +08:00
|
|
|
if (stat & DW_IC_INTR_STOP_DET)
|
2011-10-07 02:26:25 +08:00
|
|
|
dw_readl(dev, DW_IC_CLR_STOP_DET);
|
2009-11-06 20:44:37 +08:00
|
|
|
if (stat & DW_IC_INTR_START_DET)
|
2011-10-07 02:26:25 +08:00
|
|
|
dw_readl(dev, DW_IC_CLR_START_DET);
|
2009-11-06 20:44:37 +08:00
|
|
|
if (stat & DW_IC_INTR_GEN_CALL)
|
2011-10-07 02:26:25 +08:00
|
|
|
dw_readl(dev, DW_IC_CLR_GEN_CALL);
|
2009-11-06 20:44:37 +08:00
|
|
|
|
|
|
|
return stat;
|
|
|
|
}
|
|
|
|
|
2009-06-22 21:36:29 +08:00
|
|
|
/*
|
2017-06-14 18:43:22 +08:00
|
|
|
* Interrupt service routine. This gets called whenever an I2C master interrupt
|
2009-06-22 21:36:29 +08:00
|
|
|
* occurs.
|
|
|
|
*/
|
2017-06-14 18:43:22 +08:00
|
|
|
static int i2c_dw_irq_handler_master(struct dw_i2c_dev *dev)
|
2009-06-22 21:36:29 +08:00
|
|
|
{
|
2017-06-14 18:43:22 +08:00
|
|
|
u32 stat;
|
2009-06-22 21:36:29 +08:00
|
|
|
|
2009-11-06 20:44:37 +08:00
|
|
|
stat = i2c_dw_read_clear_intrbits(dev);
|
2009-06-22 21:36:29 +08:00
|
|
|
if (stat & DW_IC_INTR_TX_ABRT) {
|
|
|
|
dev->cmd_err |= DW_IC_ERR_TX_ABRT;
|
|
|
|
dev->status = STATUS_IDLE;
|
2009-11-06 20:51:36 +08:00
|
|
|
|
|
|
|
/*
|
|
|
|
* Anytime TX_ABRT is set, the contents of the tx/rx
|
2017-06-14 18:43:21 +08:00
|
|
|
* buffers are flushed. Make sure to skip them.
|
2009-11-06 20:51:36 +08:00
|
|
|
*/
|
2011-10-07 02:26:25 +08:00
|
|
|
dw_writel(dev, 0, DW_IC_INTR_MASK);
|
2009-11-06 20:51:36 +08:00
|
|
|
goto tx_aborted;
|
i2c-designware: Process i2c_msg messages in the interrupt handler
Symptom:
--------
When we're going to send/receive the longer size of data than the Tx
FIFO length, the I2C transaction will be divided into several separated
transactions, limited by the Tx FIFO length.
Details:
--------
As a hardware feature, DW I2C core generates a STOP condition whenever
the Tx FIFO becomes empty (strictly speaking, whenever the last byte in
the Tx FIFO is sent out), even if we have more bytes to be written.
Then, once a new transmit data is written to the Tx FIFO, DW I2C core
will initiate a new transaction, which leads to another START condition.
This explains how the transaction in question goes, and implies that
current tasklet-based dw_i2c_pump_msg() strategy couldn't meet the
timing constraint required for avoiding Tx FIFO underrun.
To avoid this scenario, we must keep providing new transmit data within
a given time period. In case of Fast-mode + 32-byte Tx FIFO, for
instance, it takes about 22.5[us] to process single byte, and 720[us] in
total.
This patch removes the existing tasklet-based "pump" system, and move
its jobs into the interrupt handler.
Signed-off-by: Shinya Kuribayashi <shinya.kuribayashi@necel.com>
Acked-by: Baruch Siach <baruch@tkos.co.il>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
2009-11-06 20:47:51 +08:00
|
|
|
}
|
|
|
|
|
2009-11-06 20:48:33 +08:00
|
|
|
if (stat & DW_IC_INTR_RX_FULL)
|
i2c-designware: Process i2c_msg messages in the interrupt handler
Symptom:
--------
When we're going to send/receive the longer size of data than the Tx
FIFO length, the I2C transaction will be divided into several separated
transactions, limited by the Tx FIFO length.
Details:
--------
As a hardware feature, DW I2C core generates a STOP condition whenever
the Tx FIFO becomes empty (strictly speaking, whenever the last byte in
the Tx FIFO is sent out), even if we have more bytes to be written.
Then, once a new transmit data is written to the Tx FIFO, DW I2C core
will initiate a new transaction, which leads to another START condition.
This explains how the transaction in question goes, and implies that
current tasklet-based dw_i2c_pump_msg() strategy couldn't meet the
timing constraint required for avoiding Tx FIFO underrun.
To avoid this scenario, we must keep providing new transmit data within
a given time period. In case of Fast-mode + 32-byte Tx FIFO, for
instance, it takes about 22.5[us] to process single byte, and 720[us] in
total.
This patch removes the existing tasklet-based "pump" system, and move
its jobs into the interrupt handler.
Signed-off-by: Shinya Kuribayashi <shinya.kuribayashi@necel.com>
Acked-by: Baruch Siach <baruch@tkos.co.il>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
2009-11-06 20:47:51 +08:00
|
|
|
i2c_dw_read(dev);
|
2009-11-06 20:48:33 +08:00
|
|
|
|
|
|
|
if (stat & DW_IC_INTR_TX_EMPTY)
|
i2c-designware: Process i2c_msg messages in the interrupt handler
Symptom:
--------
When we're going to send/receive the longer size of data than the Tx
FIFO length, the I2C transaction will be divided into several separated
transactions, limited by the Tx FIFO length.
Details:
--------
As a hardware feature, DW I2C core generates a STOP condition whenever
the Tx FIFO becomes empty (strictly speaking, whenever the last byte in
the Tx FIFO is sent out), even if we have more bytes to be written.
Then, once a new transmit data is written to the Tx FIFO, DW I2C core
will initiate a new transaction, which leads to another START condition.
This explains how the transaction in question goes, and implies that
current tasklet-based dw_i2c_pump_msg() strategy couldn't meet the
timing constraint required for avoiding Tx FIFO underrun.
To avoid this scenario, we must keep providing new transmit data within
a given time period. In case of Fast-mode + 32-byte Tx FIFO, for
instance, it takes about 22.5[us] to process single byte, and 720[us] in
total.
This patch removes the existing tasklet-based "pump" system, and move
its jobs into the interrupt handler.
Signed-off-by: Shinya Kuribayashi <shinya.kuribayashi@necel.com>
Acked-by: Baruch Siach <baruch@tkos.co.il>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
2009-11-06 20:47:51 +08:00
|
|
|
i2c_dw_xfer_msg(dev);
|
|
|
|
|
|
|
|
/*
|
|
|
|
* No need to modify or disable the interrupt mask here.
|
|
|
|
* i2c_dw_xfer_msg() will take care of it according to
|
|
|
|
* the current transmit status.
|
|
|
|
*/
|
2009-06-22 21:36:29 +08:00
|
|
|
|
2009-11-06 20:51:36 +08:00
|
|
|
tx_aborted:
|
2016-11-25 23:22:27 +08:00
|
|
|
if ((stat & (DW_IC_INTR_TX_ABRT | DW_IC_INTR_STOP_DET)) || dev->msg_err)
|
2009-06-22 21:36:29 +08:00
|
|
|
complete(&dev->cmd_complete);
|
2017-02-10 18:27:53 +08:00
|
|
|
else if (unlikely(dev->flags & ACCESS_INTR_MASK)) {
|
2017-06-14 18:43:21 +08:00
|
|
|
/* Workaround to trigger pending interrupt */
|
2015-12-11 20:02:53 +08:00
|
|
|
stat = dw_readl(dev, DW_IC_INTR_MASK);
|
|
|
|
i2c_dw_disable_int(dev);
|
|
|
|
dw_writel(dev, stat, DW_IC_INTR_MASK);
|
|
|
|
}
|
2009-06-22 21:36:29 +08:00
|
|
|
|
2017-06-14 18:43:22 +08:00
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
|
|
|
|
static irqreturn_t i2c_dw_isr(int this_irq, void *dev_id)
|
|
|
|
{
|
|
|
|
struct dw_i2c_dev *dev = dev_id;
|
|
|
|
u32 stat, enabled;
|
|
|
|
|
|
|
|
enabled = dw_readl(dev, DW_IC_ENABLE);
|
|
|
|
stat = dw_readl(dev, DW_IC_RAW_INTR_STAT);
|
|
|
|
dev_dbg(dev->dev, "enabled=%#x stat=%#x\n", enabled, stat);
|
|
|
|
if (!enabled || !(stat & ~DW_IC_INTR_ACTIVITY))
|
|
|
|
return IRQ_NONE;
|
|
|
|
|
|
|
|
i2c_dw_irq_handler_master(dev);
|
|
|
|
|
2009-06-22 21:36:29 +08:00
|
|
|
return IRQ_HANDLED;
|
|
|
|
}
|
2011-10-07 02:26:34 +08:00
|
|
|
|
2017-11-02 10:40:27 +08:00
|
|
|
static void i2c_dw_prepare_recovery(struct i2c_adapter *adap)
|
|
|
|
{
|
|
|
|
struct dw_i2c_dev *dev = i2c_get_adapdata(adap);
|
|
|
|
|
|
|
|
i2c_dw_disable(dev);
|
|
|
|
reset_control_assert(dev->rst);
|
|
|
|
i2c_dw_prepare_clk(dev, false);
|
|
|
|
}
|
|
|
|
|
|
|
|
static void i2c_dw_unprepare_recovery(struct i2c_adapter *adap)
|
|
|
|
{
|
|
|
|
struct dw_i2c_dev *dev = i2c_get_adapdata(adap);
|
|
|
|
|
|
|
|
i2c_dw_prepare_clk(dev, true);
|
|
|
|
reset_control_deassert(dev->rst);
|
|
|
|
i2c_dw_init_master(dev);
|
|
|
|
}
|
|
|
|
|
|
|
|
static int i2c_dw_init_recovery_info(struct dw_i2c_dev *dev)
|
|
|
|
{
|
|
|
|
struct i2c_bus_recovery_info *rinfo = &dev->rinfo;
|
|
|
|
struct i2c_adapter *adap = &dev->adapter;
|
|
|
|
struct gpio_desc *gpio;
|
|
|
|
int r;
|
|
|
|
|
|
|
|
gpio = devm_gpiod_get(dev->dev, "scl", GPIOD_OUT_HIGH);
|
|
|
|
if (IS_ERR(gpio)) {
|
|
|
|
r = PTR_ERR(gpio);
|
2018-02-18 04:58:43 +08:00
|
|
|
if (r == -ENOENT || r == -ENOSYS)
|
2017-11-02 10:40:27 +08:00
|
|
|
return 0;
|
|
|
|
return r;
|
|
|
|
}
|
|
|
|
rinfo->scl_gpiod = gpio;
|
|
|
|
|
|
|
|
gpio = devm_gpiod_get_optional(dev->dev, "sda", GPIOD_IN);
|
|
|
|
if (IS_ERR(gpio))
|
|
|
|
return PTR_ERR(gpio);
|
|
|
|
rinfo->sda_gpiod = gpio;
|
|
|
|
|
|
|
|
rinfo->recover_bus = i2c_generic_scl_recovery;
|
|
|
|
rinfo->prepare_recovery = i2c_dw_prepare_recovery;
|
|
|
|
rinfo->unprepare_recovery = i2c_dw_unprepare_recovery;
|
|
|
|
adap->bus_recovery_info = rinfo;
|
|
|
|
|
|
|
|
dev_info(dev->dev, "running with gpio recovery mode! scl%s",
|
|
|
|
rinfo->sda_gpiod ? ",sda" : "");
|
|
|
|
|
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
|
2015-10-12 21:55:35 +08:00
|
|
|
int i2c_dw_probe(struct dw_i2c_dev *dev)
|
|
|
|
{
|
|
|
|
struct i2c_adapter *adap = &dev->adapter;
|
2017-03-14 06:25:09 +08:00
|
|
|
unsigned long irq_flags;
|
2017-06-14 18:43:21 +08:00
|
|
|
int ret;
|
2015-10-12 21:55:35 +08:00
|
|
|
|
|
|
|
init_completion(&dev->cmd_complete);
|
|
|
|
|
2017-06-28 22:23:28 +08:00
|
|
|
dev->init = i2c_dw_init_master;
|
2017-06-14 18:43:23 +08:00
|
|
|
dev->disable = i2c_dw_disable;
|
|
|
|
dev->disable_int = i2c_dw_disable_int;
|
|
|
|
|
|
|
|
ret = dev->init(dev);
|
2017-06-14 18:43:21 +08:00
|
|
|
if (ret)
|
|
|
|
return ret;
|
2015-10-12 21:55:35 +08:00
|
|
|
|
|
|
|
snprintf(adap->name, sizeof(adap->name),
|
|
|
|
"Synopsys DesignWare I2C adapter");
|
2015-12-24 00:43:24 +08:00
|
|
|
adap->retries = 3;
|
2015-10-12 21:55:35 +08:00
|
|
|
adap->algo = &i2c_dw_algo;
|
|
|
|
adap->dev.parent = dev->dev;
|
|
|
|
i2c_set_adapdata(adap, dev);
|
|
|
|
|
2017-03-14 06:25:09 +08:00
|
|
|
if (dev->pm_disabled) {
|
|
|
|
dev_pm_syscore_device(dev->dev, true);
|
|
|
|
irq_flags = IRQF_NO_SUSPEND;
|
|
|
|
} else {
|
|
|
|
irq_flags = IRQF_SHARED | IRQF_COND_SUSPEND;
|
|
|
|
}
|
|
|
|
|
2015-10-12 21:55:35 +08:00
|
|
|
i2c_dw_disable_int(dev);
|
2017-06-14 18:43:21 +08:00
|
|
|
ret = devm_request_irq(dev->dev, dev->irq, i2c_dw_isr, irq_flags,
|
|
|
|
dev_name(dev->dev), dev);
|
|
|
|
if (ret) {
|
2015-10-12 21:55:35 +08:00
|
|
|
dev_err(dev->dev, "failure requesting irq %i: %d\n",
|
2017-06-14 18:43:21 +08:00
|
|
|
dev->irq, ret);
|
|
|
|
return ret;
|
2015-10-12 21:55:35 +08:00
|
|
|
}
|
|
|
|
|
2017-11-02 10:40:27 +08:00
|
|
|
ret = i2c_dw_init_recovery_info(dev);
|
|
|
|
if (ret)
|
|
|
|
return ret;
|
|
|
|
|
2016-02-11 22:36:03 +08:00
|
|
|
/*
|
|
|
|
* Increment PM usage count during adapter registration in order to
|
|
|
|
* avoid possible spurious runtime suspend when adapter device is
|
|
|
|
* registered to the device core and immediate resume in case bus has
|
|
|
|
* registered I2C slaves that do I2C transfers in their probe.
|
|
|
|
*/
|
|
|
|
pm_runtime_get_noresume(dev->dev);
|
2017-06-14 18:43:21 +08:00
|
|
|
ret = i2c_add_numbered_adapter(adap);
|
|
|
|
if (ret)
|
|
|
|
dev_err(dev->dev, "failure adding adapter: %d\n", ret);
|
2016-02-11 22:36:03 +08:00
|
|
|
pm_runtime_put_noidle(dev->dev);
|
2015-10-12 21:55:35 +08:00
|
|
|
|
2017-06-14 18:43:21 +08:00
|
|
|
return ret;
|
2015-10-12 21:55:35 +08:00
|
|
|
}
|
|
|
|
EXPORT_SYMBOL_GPL(i2c_dw_probe);
|
|
|
|
|
2017-06-14 18:43:23 +08:00
|
|
|
MODULE_DESCRIPTION("Synopsys DesignWare I2C bus master adapter");
|
2013-01-17 18:31:04 +08:00
|
|
|
MODULE_LICENSE("GPL");
|