mirror of https://gitee.com/openkylin/linux.git
1260 lines
30 KiB
C
1260 lines
30 KiB
C
/*
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* ADS7846 based touchscreen and sensor driver
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*
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* Copyright (c) 2005 David Brownell
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* Copyright (c) 2006 Nokia Corporation
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* Various changes: Imre Deak <imre.deak@nokia.com>
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*
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* Using code from:
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* - corgi_ts.c
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* Copyright (C) 2004-2005 Richard Purdie
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* - omap_ts.[hc], ads7846.h, ts_osk.c
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* Copyright (C) 2002 MontaVista Software
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* Copyright (C) 2004 Texas Instruments
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* Copyright (C) 2005 Dirk Behme
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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 version 2 as
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* published by the Free Software Foundation.
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*/
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#include <linux/hwmon.h>
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#include <linux/init.h>
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#include <linux/err.h>
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#include <linux/delay.h>
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#include <linux/input.h>
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#include <linux/interrupt.h>
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#include <linux/slab.h>
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#include <linux/gpio.h>
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#include <linux/spi/spi.h>
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#include <linux/spi/ads7846.h>
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#include <asm/irq.h>
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/*
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* This code has been heavily tested on a Nokia 770, and lightly
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* tested on other ads7846 devices (OSK/Mistral, Lubbock).
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* TSC2046 is just newer ads7846 silicon.
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* Support for ads7843 tested on Atmel at91sam926x-EK.
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* Support for ads7845 has only been stubbed in.
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*
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* IRQ handling needs a workaround because of a shortcoming in handling
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* edge triggered IRQs on some platforms like the OMAP1/2. These
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* platforms don't handle the ARM lazy IRQ disabling properly, thus we
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* have to maintain our own SW IRQ disabled status. This should be
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* removed as soon as the affected platform's IRQ handling is fixed.
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*
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* app note sbaa036 talks in more detail about accurate sampling...
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* that ought to help in situations like LCDs inducing noise (which
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* can also be helped by using synch signals) and more generally.
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* This driver tries to utilize the measures described in the app
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* note. The strength of filtering can be set in the board-* specific
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* files.
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*/
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#define TS_POLL_DELAY (1 * 1000000) /* ns delay before the first sample */
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#define TS_POLL_PERIOD (5 * 1000000) /* ns delay between samples */
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/* this driver doesn't aim at the peak continuous sample rate */
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#define SAMPLE_BITS (8 /*cmd*/ + 16 /*sample*/ + 2 /* before, after */)
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struct ts_event {
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/* For portability, we can't read 12 bit values using SPI (which
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* would make the controller deliver them as native byteorder u16
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* with msbs zeroed). Instead, we read them as two 8-bit values,
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* *** WHICH NEED BYTESWAPPING *** and range adjustment.
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*/
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u16 x;
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u16 y;
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u16 z1, z2;
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int ignore;
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};
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/*
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* We allocate this separately to avoid cache line sharing issues when
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* driver is used with DMA-based SPI controllers (like atmel_spi) on
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* systems where main memory is not DMA-coherent (most non-x86 boards).
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*/
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struct ads7846_packet {
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u8 read_x, read_y, read_z1, read_z2, pwrdown;
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u16 dummy; /* for the pwrdown read */
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struct ts_event tc;
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};
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struct ads7846 {
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struct input_dev *input;
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char phys[32];
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char name[32];
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struct spi_device *spi;
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#if defined(CONFIG_HWMON) || defined(CONFIG_HWMON_MODULE)
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struct attribute_group *attr_group;
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struct device *hwmon;
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#endif
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u16 model;
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u16 vref_mv;
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u16 vref_delay_usecs;
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u16 x_plate_ohms;
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u16 pressure_max;
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bool swap_xy;
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struct ads7846_packet *packet;
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struct spi_transfer xfer[18];
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struct spi_message msg[5];
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struct spi_message *last_msg;
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int msg_idx;
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int read_cnt;
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int read_rep;
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int last_read;
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u16 debounce_max;
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u16 debounce_tol;
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u16 debounce_rep;
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u16 penirq_recheck_delay_usecs;
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spinlock_t lock;
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struct hrtimer timer;
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unsigned pendown:1; /* P: lock */
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unsigned pending:1; /* P: lock */
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// FIXME remove "irq_disabled"
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unsigned irq_disabled:1; /* P: lock */
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unsigned disabled:1;
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unsigned is_suspended:1;
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int (*filter)(void *data, int data_idx, int *val);
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void *filter_data;
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void (*filter_cleanup)(void *data);
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int (*get_pendown_state)(void);
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int gpio_pendown;
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void (*wait_for_sync)(void);
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};
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/* leave chip selected when we're done, for quicker re-select? */
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#if 0
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#define CS_CHANGE(xfer) ((xfer).cs_change = 1)
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#else
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#define CS_CHANGE(xfer) ((xfer).cs_change = 0)
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#endif
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/*--------------------------------------------------------------------------*/
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/* The ADS7846 has touchscreen and other sensors.
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* Earlier ads784x chips are somewhat compatible.
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*/
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#define ADS_START (1 << 7)
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#define ADS_A2A1A0_d_y (1 << 4) /* differential */
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#define ADS_A2A1A0_d_z1 (3 << 4) /* differential */
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#define ADS_A2A1A0_d_z2 (4 << 4) /* differential */
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#define ADS_A2A1A0_d_x (5 << 4) /* differential */
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#define ADS_A2A1A0_temp0 (0 << 4) /* non-differential */
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#define ADS_A2A1A0_vbatt (2 << 4) /* non-differential */
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#define ADS_A2A1A0_vaux (6 << 4) /* non-differential */
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#define ADS_A2A1A0_temp1 (7 << 4) /* non-differential */
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#define ADS_8_BIT (1 << 3)
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#define ADS_12_BIT (0 << 3)
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#define ADS_SER (1 << 2) /* non-differential */
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#define ADS_DFR (0 << 2) /* differential */
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#define ADS_PD10_PDOWN (0 << 0) /* lowpower mode + penirq */
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#define ADS_PD10_ADC_ON (1 << 0) /* ADC on */
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#define ADS_PD10_REF_ON (2 << 0) /* vREF on + penirq */
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#define ADS_PD10_ALL_ON (3 << 0) /* ADC + vREF on */
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#define MAX_12BIT ((1<<12)-1)
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/* leave ADC powered up (disables penirq) between differential samples */
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#define READ_12BIT_DFR(x, adc, vref) (ADS_START | ADS_A2A1A0_d_ ## x \
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| ADS_12_BIT | ADS_DFR | \
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(adc ? ADS_PD10_ADC_ON : 0) | (vref ? ADS_PD10_REF_ON : 0))
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#define READ_Y(vref) (READ_12BIT_DFR(y, 1, vref))
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#define READ_Z1(vref) (READ_12BIT_DFR(z1, 1, vref))
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#define READ_Z2(vref) (READ_12BIT_DFR(z2, 1, vref))
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#define READ_X(vref) (READ_12BIT_DFR(x, 1, vref))
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#define PWRDOWN (READ_12BIT_DFR(y, 0, 0)) /* LAST */
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/* single-ended samples need to first power up reference voltage;
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* we leave both ADC and VREF powered
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*/
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#define READ_12BIT_SER(x) (ADS_START | ADS_A2A1A0_ ## x \
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| ADS_12_BIT | ADS_SER)
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#define REF_ON (READ_12BIT_DFR(x, 1, 1))
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#define REF_OFF (READ_12BIT_DFR(y, 0, 0))
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/*--------------------------------------------------------------------------*/
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/*
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* Non-touchscreen sensors only use single-ended conversions.
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* The range is GND..vREF. The ads7843 and ads7835 must use external vREF;
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* ads7846 lets that pin be unconnected, to use internal vREF.
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*/
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struct ser_req {
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u8 ref_on;
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u8 command;
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u8 ref_off;
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u16 scratch;
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__be16 sample;
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struct spi_message msg;
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struct spi_transfer xfer[6];
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};
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static void ads7846_enable(struct ads7846 *ts);
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static void ads7846_disable(struct ads7846 *ts);
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static int device_suspended(struct device *dev)
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{
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struct ads7846 *ts = dev_get_drvdata(dev);
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return ts->is_suspended || ts->disabled;
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}
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static int ads7846_read12_ser(struct device *dev, unsigned command)
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{
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struct spi_device *spi = to_spi_device(dev);
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struct ads7846 *ts = dev_get_drvdata(dev);
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struct ser_req *req = kzalloc(sizeof *req, GFP_KERNEL);
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int status;
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int use_internal;
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if (!req)
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return -ENOMEM;
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spi_message_init(&req->msg);
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/* FIXME boards with ads7846 might use external vref instead ... */
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use_internal = (ts->model == 7846);
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/* maybe turn on internal vREF, and let it settle */
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if (use_internal) {
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req->ref_on = REF_ON;
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req->xfer[0].tx_buf = &req->ref_on;
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req->xfer[0].len = 1;
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spi_message_add_tail(&req->xfer[0], &req->msg);
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req->xfer[1].rx_buf = &req->scratch;
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req->xfer[1].len = 2;
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/* for 1uF, settle for 800 usec; no cap, 100 usec. */
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req->xfer[1].delay_usecs = ts->vref_delay_usecs;
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spi_message_add_tail(&req->xfer[1], &req->msg);
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}
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/* take sample */
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req->command = (u8) command;
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req->xfer[2].tx_buf = &req->command;
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req->xfer[2].len = 1;
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spi_message_add_tail(&req->xfer[2], &req->msg);
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req->xfer[3].rx_buf = &req->sample;
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req->xfer[3].len = 2;
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spi_message_add_tail(&req->xfer[3], &req->msg);
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/* REVISIT: take a few more samples, and compare ... */
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/* converter in low power mode & enable PENIRQ */
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req->ref_off = PWRDOWN;
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req->xfer[4].tx_buf = &req->ref_off;
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req->xfer[4].len = 1;
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spi_message_add_tail(&req->xfer[4], &req->msg);
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req->xfer[5].rx_buf = &req->scratch;
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req->xfer[5].len = 2;
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CS_CHANGE(req->xfer[5]);
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spi_message_add_tail(&req->xfer[5], &req->msg);
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ts->irq_disabled = 1;
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disable_irq(spi->irq);
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status = spi_sync(spi, &req->msg);
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ts->irq_disabled = 0;
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enable_irq(spi->irq);
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if (status == 0) {
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/* on-wire is a must-ignore bit, a BE12 value, then padding */
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status = be16_to_cpu(req->sample);
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status = status >> 3;
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status &= 0x0fff;
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}
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kfree(req);
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return status;
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}
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#if defined(CONFIG_HWMON) || defined(CONFIG_HWMON_MODULE)
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#define SHOW(name, var, adjust) static ssize_t \
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name ## _show(struct device *dev, struct device_attribute *attr, char *buf) \
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{ \
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struct ads7846 *ts = dev_get_drvdata(dev); \
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ssize_t v = ads7846_read12_ser(dev, \
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READ_12BIT_SER(var) | ADS_PD10_ALL_ON); \
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if (v < 0) \
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return v; \
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return sprintf(buf, "%u\n", adjust(ts, v)); \
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} \
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static DEVICE_ATTR(name, S_IRUGO, name ## _show, NULL);
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/* Sysfs conventions report temperatures in millidegrees Celsius.
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* ADS7846 could use the low-accuracy two-sample scheme, but can't do the high
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* accuracy scheme without calibration data. For now we won't try either;
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* userspace sees raw sensor values, and must scale/calibrate appropriately.
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*/
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static inline unsigned null_adjust(struct ads7846 *ts, ssize_t v)
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{
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return v;
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}
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SHOW(temp0, temp0, null_adjust) /* temp1_input */
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SHOW(temp1, temp1, null_adjust) /* temp2_input */
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/* sysfs conventions report voltages in millivolts. We can convert voltages
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* if we know vREF. userspace may need to scale vAUX to match the board's
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* external resistors; we assume that vBATT only uses the internal ones.
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*/
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static inline unsigned vaux_adjust(struct ads7846 *ts, ssize_t v)
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{
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unsigned retval = v;
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/* external resistors may scale vAUX into 0..vREF */
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retval *= ts->vref_mv;
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retval = retval >> 12;
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return retval;
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}
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static inline unsigned vbatt_adjust(struct ads7846 *ts, ssize_t v)
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{
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unsigned retval = vaux_adjust(ts, v);
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/* ads7846 has a resistor ladder to scale this signal down */
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if (ts->model == 7846)
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retval *= 4;
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return retval;
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}
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SHOW(in0_input, vaux, vaux_adjust)
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SHOW(in1_input, vbatt, vbatt_adjust)
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static struct attribute *ads7846_attributes[] = {
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&dev_attr_temp0.attr,
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&dev_attr_temp1.attr,
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&dev_attr_in0_input.attr,
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&dev_attr_in1_input.attr,
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NULL,
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};
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static struct attribute_group ads7846_attr_group = {
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.attrs = ads7846_attributes,
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};
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static struct attribute *ads7843_attributes[] = {
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&dev_attr_in0_input.attr,
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&dev_attr_in1_input.attr,
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NULL,
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};
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static struct attribute_group ads7843_attr_group = {
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.attrs = ads7843_attributes,
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};
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static struct attribute *ads7845_attributes[] = {
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&dev_attr_in0_input.attr,
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NULL,
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};
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static struct attribute_group ads7845_attr_group = {
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.attrs = ads7845_attributes,
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};
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static int ads784x_hwmon_register(struct spi_device *spi, struct ads7846 *ts)
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{
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struct device *hwmon;
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int err;
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/* hwmon sensors need a reference voltage */
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switch (ts->model) {
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case 7846:
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if (!ts->vref_mv) {
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dev_dbg(&spi->dev, "assuming 2.5V internal vREF\n");
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ts->vref_mv = 2500;
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}
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break;
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case 7845:
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case 7843:
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if (!ts->vref_mv) {
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dev_warn(&spi->dev,
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"external vREF for ADS%d not specified\n",
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ts->model);
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return 0;
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}
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break;
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}
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/* different chips have different sensor groups */
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switch (ts->model) {
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case 7846:
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ts->attr_group = &ads7846_attr_group;
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break;
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case 7845:
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ts->attr_group = &ads7845_attr_group;
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break;
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case 7843:
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ts->attr_group = &ads7843_attr_group;
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break;
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default:
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dev_dbg(&spi->dev, "ADS%d not recognized\n", ts->model);
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return 0;
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}
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err = sysfs_create_group(&spi->dev.kobj, ts->attr_group);
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if (err)
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return err;
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hwmon = hwmon_device_register(&spi->dev);
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if (IS_ERR(hwmon)) {
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sysfs_remove_group(&spi->dev.kobj, ts->attr_group);
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return PTR_ERR(hwmon);
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}
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ts->hwmon = hwmon;
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return 0;
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}
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static void ads784x_hwmon_unregister(struct spi_device *spi,
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struct ads7846 *ts)
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{
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if (ts->hwmon) {
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sysfs_remove_group(&spi->dev.kobj, ts->attr_group);
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hwmon_device_unregister(ts->hwmon);
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}
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}
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#else
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static inline int ads784x_hwmon_register(struct spi_device *spi,
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struct ads7846 *ts)
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{
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return 0;
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}
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static inline void ads784x_hwmon_unregister(struct spi_device *spi,
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struct ads7846 *ts)
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{
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}
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#endif
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static int is_pen_down(struct device *dev)
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{
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struct ads7846 *ts = dev_get_drvdata(dev);
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return ts->pendown;
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}
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static ssize_t ads7846_pen_down_show(struct device *dev,
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struct device_attribute *attr, char *buf)
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{
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return sprintf(buf, "%u\n", is_pen_down(dev));
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}
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static DEVICE_ATTR(pen_down, S_IRUGO, ads7846_pen_down_show, NULL);
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static ssize_t ads7846_disable_show(struct device *dev,
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struct device_attribute *attr, char *buf)
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{
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struct ads7846 *ts = dev_get_drvdata(dev);
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return sprintf(buf, "%u\n", ts->disabled);
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}
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static ssize_t ads7846_disable_store(struct device *dev,
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struct device_attribute *attr,
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const char *buf, size_t count)
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{
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struct ads7846 *ts = dev_get_drvdata(dev);
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unsigned long i;
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if (strict_strtoul(buf, 10, &i))
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return -EINVAL;
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spin_lock_irq(&ts->lock);
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if (i)
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ads7846_disable(ts);
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else
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ads7846_enable(ts);
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spin_unlock_irq(&ts->lock);
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return count;
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}
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static DEVICE_ATTR(disable, 0664, ads7846_disable_show, ads7846_disable_store);
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static struct attribute *ads784x_attributes[] = {
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&dev_attr_pen_down.attr,
|
|
&dev_attr_disable.attr,
|
|
NULL,
|
|
};
|
|
|
|
static struct attribute_group ads784x_attr_group = {
|
|
.attrs = ads784x_attributes,
|
|
};
|
|
|
|
/*--------------------------------------------------------------------------*/
|
|
|
|
static int get_pendown_state(struct ads7846 *ts)
|
|
{
|
|
if (ts->get_pendown_state)
|
|
return ts->get_pendown_state();
|
|
|
|
return !gpio_get_value(ts->gpio_pendown);
|
|
}
|
|
|
|
static void null_wait_for_sync(void)
|
|
{
|
|
}
|
|
|
|
/*
|
|
* PENIRQ only kicks the timer. The timer only reissues the SPI transfer,
|
|
* to retrieve touchscreen status.
|
|
*
|
|
* The SPI transfer completion callback does the real work. It reports
|
|
* touchscreen events and reactivates the timer (or IRQ) as appropriate.
|
|
*/
|
|
|
|
static void ads7846_rx(void *ads)
|
|
{
|
|
struct ads7846 *ts = ads;
|
|
struct ads7846_packet *packet = ts->packet;
|
|
unsigned Rt;
|
|
u16 x, y, z1, z2;
|
|
|
|
/* ads7846_rx_val() did in-place conversion (including byteswap) from
|
|
* on-the-wire format as part of debouncing to get stable readings.
|
|
*/
|
|
x = packet->tc.x;
|
|
y = packet->tc.y;
|
|
z1 = packet->tc.z1;
|
|
z2 = packet->tc.z2;
|
|
|
|
/* range filtering */
|
|
if (x == MAX_12BIT)
|
|
x = 0;
|
|
|
|
if (ts->model == 7843) {
|
|
Rt = ts->pressure_max / 2;
|
|
} else if (likely(x && z1)) {
|
|
/* compute touch pressure resistance using equation #2 */
|
|
Rt = z2;
|
|
Rt -= z1;
|
|
Rt *= x;
|
|
Rt *= ts->x_plate_ohms;
|
|
Rt /= z1;
|
|
Rt = (Rt + 2047) >> 12;
|
|
} else {
|
|
Rt = 0;
|
|
}
|
|
|
|
/* Sample found inconsistent by debouncing or pressure is beyond
|
|
* the maximum. Don't report it to user space, repeat at least
|
|
* once more the measurement
|
|
*/
|
|
if (packet->tc.ignore || Rt > ts->pressure_max) {
|
|
#ifdef VERBOSE
|
|
pr_debug("%s: ignored %d pressure %d\n",
|
|
dev_name(&ts->spi->dev), packet->tc.ignore, Rt);
|
|
#endif
|
|
hrtimer_start(&ts->timer, ktime_set(0, TS_POLL_PERIOD),
|
|
HRTIMER_MODE_REL);
|
|
return;
|
|
}
|
|
|
|
/* Maybe check the pendown state before reporting. This discards
|
|
* false readings when the pen is lifted.
|
|
*/
|
|
if (ts->penirq_recheck_delay_usecs) {
|
|
udelay(ts->penirq_recheck_delay_usecs);
|
|
if (!get_pendown_state(ts))
|
|
Rt = 0;
|
|
}
|
|
|
|
/* NOTE: We can't rely on the pressure to determine the pen down
|
|
* state, even this controller has a pressure sensor. The pressure
|
|
* value can fluctuate for quite a while after lifting the pen and
|
|
* in some cases may not even settle at the expected value.
|
|
*
|
|
* The only safe way to check for the pen up condition is in the
|
|
* timer by reading the pen signal state (it's a GPIO _and_ IRQ).
|
|
*/
|
|
if (Rt) {
|
|
struct input_dev *input = ts->input;
|
|
|
|
if (!ts->pendown) {
|
|
input_report_key(input, BTN_TOUCH, 1);
|
|
ts->pendown = 1;
|
|
#ifdef VERBOSE
|
|
dev_dbg(&ts->spi->dev, "DOWN\n");
|
|
#endif
|
|
}
|
|
|
|
if (ts->swap_xy)
|
|
swap(x, y);
|
|
|
|
input_report_abs(input, ABS_X, x);
|
|
input_report_abs(input, ABS_Y, y);
|
|
input_report_abs(input, ABS_PRESSURE, Rt);
|
|
|
|
input_sync(input);
|
|
#ifdef VERBOSE
|
|
dev_dbg(&ts->spi->dev, "%4d/%4d/%4d\n", x, y, Rt);
|
|
#endif
|
|
}
|
|
|
|
hrtimer_start(&ts->timer, ktime_set(0, TS_POLL_PERIOD),
|
|
HRTIMER_MODE_REL);
|
|
}
|
|
|
|
static int ads7846_debounce(void *ads, int data_idx, int *val)
|
|
{
|
|
struct ads7846 *ts = ads;
|
|
|
|
if (!ts->read_cnt || (abs(ts->last_read - *val) > ts->debounce_tol)) {
|
|
/* Start over collecting consistent readings. */
|
|
ts->read_rep = 0;
|
|
/* Repeat it, if this was the first read or the read
|
|
* wasn't consistent enough. */
|
|
if (ts->read_cnt < ts->debounce_max) {
|
|
ts->last_read = *val;
|
|
ts->read_cnt++;
|
|
return ADS7846_FILTER_REPEAT;
|
|
} else {
|
|
/* Maximum number of debouncing reached and still
|
|
* not enough number of consistent readings. Abort
|
|
* the whole sample, repeat it in the next sampling
|
|
* period.
|
|
*/
|
|
ts->read_cnt = 0;
|
|
return ADS7846_FILTER_IGNORE;
|
|
}
|
|
} else {
|
|
if (++ts->read_rep > ts->debounce_rep) {
|
|
/* Got a good reading for this coordinate,
|
|
* go for the next one. */
|
|
ts->read_cnt = 0;
|
|
ts->read_rep = 0;
|
|
return ADS7846_FILTER_OK;
|
|
} else {
|
|
/* Read more values that are consistent. */
|
|
ts->read_cnt++;
|
|
return ADS7846_FILTER_REPEAT;
|
|
}
|
|
}
|
|
}
|
|
|
|
static int ads7846_no_filter(void *ads, int data_idx, int *val)
|
|
{
|
|
return ADS7846_FILTER_OK;
|
|
}
|
|
|
|
static void ads7846_rx_val(void *ads)
|
|
{
|
|
struct ads7846 *ts = ads;
|
|
struct ads7846_packet *packet = ts->packet;
|
|
struct spi_message *m;
|
|
struct spi_transfer *t;
|
|
int val;
|
|
int action;
|
|
int status;
|
|
|
|
m = &ts->msg[ts->msg_idx];
|
|
t = list_entry(m->transfers.prev, struct spi_transfer, transfer_list);
|
|
|
|
/* adjust: on-wire is a must-ignore bit, a BE12 value, then padding;
|
|
* built from two 8 bit values written msb-first.
|
|
*/
|
|
val = be16_to_cpup((__be16 *)t->rx_buf) >> 3;
|
|
|
|
action = ts->filter(ts->filter_data, ts->msg_idx, &val);
|
|
switch (action) {
|
|
case ADS7846_FILTER_REPEAT:
|
|
break;
|
|
case ADS7846_FILTER_IGNORE:
|
|
packet->tc.ignore = 1;
|
|
/* Last message will contain ads7846_rx() as the
|
|
* completion function.
|
|
*/
|
|
m = ts->last_msg;
|
|
break;
|
|
case ADS7846_FILTER_OK:
|
|
*(u16 *)t->rx_buf = val;
|
|
packet->tc.ignore = 0;
|
|
m = &ts->msg[++ts->msg_idx];
|
|
break;
|
|
default:
|
|
BUG();
|
|
}
|
|
ts->wait_for_sync();
|
|
status = spi_async(ts->spi, m);
|
|
if (status)
|
|
dev_err(&ts->spi->dev, "spi_async --> %d\n",
|
|
status);
|
|
}
|
|
|
|
static enum hrtimer_restart ads7846_timer(struct hrtimer *handle)
|
|
{
|
|
struct ads7846 *ts = container_of(handle, struct ads7846, timer);
|
|
int status = 0;
|
|
|
|
spin_lock(&ts->lock);
|
|
|
|
if (unlikely(!get_pendown_state(ts) ||
|
|
device_suspended(&ts->spi->dev))) {
|
|
if (ts->pendown) {
|
|
struct input_dev *input = ts->input;
|
|
|
|
input_report_key(input, BTN_TOUCH, 0);
|
|
input_report_abs(input, ABS_PRESSURE, 0);
|
|
input_sync(input);
|
|
|
|
ts->pendown = 0;
|
|
#ifdef VERBOSE
|
|
dev_dbg(&ts->spi->dev, "UP\n");
|
|
#endif
|
|
}
|
|
|
|
/* measurement cycle ended */
|
|
if (!device_suspended(&ts->spi->dev)) {
|
|
ts->irq_disabled = 0;
|
|
enable_irq(ts->spi->irq);
|
|
}
|
|
ts->pending = 0;
|
|
} else {
|
|
/* pen is still down, continue with the measurement */
|
|
ts->msg_idx = 0;
|
|
ts->wait_for_sync();
|
|
status = spi_async(ts->spi, &ts->msg[0]);
|
|
if (status)
|
|
dev_err(&ts->spi->dev, "spi_async --> %d\n", status);
|
|
}
|
|
|
|
spin_unlock(&ts->lock);
|
|
return HRTIMER_NORESTART;
|
|
}
|
|
|
|
static irqreturn_t ads7846_irq(int irq, void *handle)
|
|
{
|
|
struct ads7846 *ts = handle;
|
|
unsigned long flags;
|
|
|
|
spin_lock_irqsave(&ts->lock, flags);
|
|
if (likely(get_pendown_state(ts))) {
|
|
if (!ts->irq_disabled) {
|
|
/* The ARM do_simple_IRQ() dispatcher doesn't act
|
|
* like the other dispatchers: it will report IRQs
|
|
* even after they've been disabled. We work around
|
|
* that here. (The "generic irq" framework may help...)
|
|
*/
|
|
ts->irq_disabled = 1;
|
|
disable_irq_nosync(ts->spi->irq);
|
|
ts->pending = 1;
|
|
hrtimer_start(&ts->timer, ktime_set(0, TS_POLL_DELAY),
|
|
HRTIMER_MODE_REL);
|
|
}
|
|
}
|
|
spin_unlock_irqrestore(&ts->lock, flags);
|
|
|
|
return IRQ_HANDLED;
|
|
}
|
|
|
|
/*--------------------------------------------------------------------------*/
|
|
|
|
/* Must be called with ts->lock held */
|
|
static void ads7846_disable(struct ads7846 *ts)
|
|
{
|
|
if (ts->disabled)
|
|
return;
|
|
|
|
ts->disabled = 1;
|
|
|
|
/* are we waiting for IRQ, or polling? */
|
|
if (!ts->pending) {
|
|
ts->irq_disabled = 1;
|
|
disable_irq(ts->spi->irq);
|
|
} else {
|
|
/* the timer will run at least once more, and
|
|
* leave everything in a clean state, IRQ disabled
|
|
*/
|
|
while (ts->pending) {
|
|
spin_unlock_irq(&ts->lock);
|
|
msleep(1);
|
|
spin_lock_irq(&ts->lock);
|
|
}
|
|
}
|
|
|
|
/* we know the chip's in lowpower mode since we always
|
|
* leave it that way after every request
|
|
*/
|
|
}
|
|
|
|
/* Must be called with ts->lock held */
|
|
static void ads7846_enable(struct ads7846 *ts)
|
|
{
|
|
if (!ts->disabled)
|
|
return;
|
|
|
|
ts->disabled = 0;
|
|
ts->irq_disabled = 0;
|
|
enable_irq(ts->spi->irq);
|
|
}
|
|
|
|
static int ads7846_suspend(struct spi_device *spi, pm_message_t message)
|
|
{
|
|
struct ads7846 *ts = dev_get_drvdata(&spi->dev);
|
|
|
|
spin_lock_irq(&ts->lock);
|
|
|
|
ts->is_suspended = 1;
|
|
ads7846_disable(ts);
|
|
|
|
spin_unlock_irq(&ts->lock);
|
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
static int ads7846_resume(struct spi_device *spi)
|
|
{
|
|
struct ads7846 *ts = dev_get_drvdata(&spi->dev);
|
|
|
|
spin_lock_irq(&ts->lock);
|
|
|
|
ts->is_suspended = 0;
|
|
ads7846_enable(ts);
|
|
|
|
spin_unlock_irq(&ts->lock);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int __devinit setup_pendown(struct spi_device *spi, struct ads7846 *ts)
|
|
{
|
|
struct ads7846_platform_data *pdata = spi->dev.platform_data;
|
|
int err;
|
|
|
|
/* REVISIT when the irq can be triggered active-low, or if for some
|
|
* reason the touchscreen isn't hooked up, we don't need to access
|
|
* the pendown state.
|
|
*/
|
|
if (!pdata->get_pendown_state && !gpio_is_valid(pdata->gpio_pendown)) {
|
|
dev_err(&spi->dev, "no get_pendown_state nor gpio_pendown?\n");
|
|
return -EINVAL;
|
|
}
|
|
|
|
if (pdata->get_pendown_state) {
|
|
ts->get_pendown_state = pdata->get_pendown_state;
|
|
return 0;
|
|
}
|
|
|
|
err = gpio_request(pdata->gpio_pendown, "ads7846_pendown");
|
|
if (err) {
|
|
dev_err(&spi->dev, "failed to request pendown GPIO%d\n",
|
|
pdata->gpio_pendown);
|
|
return err;
|
|
}
|
|
|
|
ts->gpio_pendown = pdata->gpio_pendown;
|
|
return 0;
|
|
}
|
|
|
|
static int __devinit ads7846_probe(struct spi_device *spi)
|
|
{
|
|
struct ads7846 *ts;
|
|
struct ads7846_packet *packet;
|
|
struct input_dev *input_dev;
|
|
struct ads7846_platform_data *pdata = spi->dev.platform_data;
|
|
struct spi_message *m;
|
|
struct spi_transfer *x;
|
|
int vref;
|
|
int err;
|
|
|
|
if (!spi->irq) {
|
|
dev_dbg(&spi->dev, "no IRQ?\n");
|
|
return -ENODEV;
|
|
}
|
|
|
|
if (!pdata) {
|
|
dev_dbg(&spi->dev, "no platform data?\n");
|
|
return -ENODEV;
|
|
}
|
|
|
|
/* don't exceed max specified sample rate */
|
|
if (spi->max_speed_hz > (125000 * SAMPLE_BITS)) {
|
|
dev_dbg(&spi->dev, "f(sample) %d KHz?\n",
|
|
(spi->max_speed_hz/SAMPLE_BITS)/1000);
|
|
return -EINVAL;
|
|
}
|
|
|
|
/* We'd set TX wordsize 8 bits and RX wordsize to 13 bits ... except
|
|
* that even if the hardware can do that, the SPI controller driver
|
|
* may not. So we stick to very-portable 8 bit words, both RX and TX.
|
|
*/
|
|
spi->bits_per_word = 8;
|
|
spi->mode = SPI_MODE_0;
|
|
err = spi_setup(spi);
|
|
if (err < 0)
|
|
return err;
|
|
|
|
ts = kzalloc(sizeof(struct ads7846), GFP_KERNEL);
|
|
packet = kzalloc(sizeof(struct ads7846_packet), GFP_KERNEL);
|
|
input_dev = input_allocate_device();
|
|
if (!ts || !packet || !input_dev) {
|
|
err = -ENOMEM;
|
|
goto err_free_mem;
|
|
}
|
|
|
|
dev_set_drvdata(&spi->dev, ts);
|
|
|
|
ts->packet = packet;
|
|
ts->spi = spi;
|
|
ts->input = input_dev;
|
|
ts->vref_mv = pdata->vref_mv;
|
|
ts->swap_xy = pdata->swap_xy;
|
|
|
|
hrtimer_init(&ts->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
|
|
ts->timer.function = ads7846_timer;
|
|
|
|
spin_lock_init(&ts->lock);
|
|
|
|
ts->model = pdata->model ? : 7846;
|
|
ts->vref_delay_usecs = pdata->vref_delay_usecs ? : 100;
|
|
ts->x_plate_ohms = pdata->x_plate_ohms ? : 400;
|
|
ts->pressure_max = pdata->pressure_max ? : ~0;
|
|
|
|
if (pdata->filter != NULL) {
|
|
if (pdata->filter_init != NULL) {
|
|
err = pdata->filter_init(pdata, &ts->filter_data);
|
|
if (err < 0)
|
|
goto err_free_mem;
|
|
}
|
|
ts->filter = pdata->filter;
|
|
ts->filter_cleanup = pdata->filter_cleanup;
|
|
} else if (pdata->debounce_max) {
|
|
ts->debounce_max = pdata->debounce_max;
|
|
if (ts->debounce_max < 2)
|
|
ts->debounce_max = 2;
|
|
ts->debounce_tol = pdata->debounce_tol;
|
|
ts->debounce_rep = pdata->debounce_rep;
|
|
ts->filter = ads7846_debounce;
|
|
ts->filter_data = ts;
|
|
} else
|
|
ts->filter = ads7846_no_filter;
|
|
|
|
err = setup_pendown(spi, ts);
|
|
if (err)
|
|
goto err_cleanup_filter;
|
|
|
|
if (pdata->penirq_recheck_delay_usecs)
|
|
ts->penirq_recheck_delay_usecs =
|
|
pdata->penirq_recheck_delay_usecs;
|
|
|
|
ts->wait_for_sync = pdata->wait_for_sync ? : null_wait_for_sync;
|
|
|
|
snprintf(ts->phys, sizeof(ts->phys), "%s/input0", dev_name(&spi->dev));
|
|
snprintf(ts->name, sizeof(ts->name), "ADS%d Touchscreen", ts->model);
|
|
|
|
input_dev->name = ts->name;
|
|
input_dev->phys = ts->phys;
|
|
input_dev->dev.parent = &spi->dev;
|
|
|
|
input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
|
|
input_dev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);
|
|
input_set_abs_params(input_dev, ABS_X,
|
|
pdata->x_min ? : 0,
|
|
pdata->x_max ? : MAX_12BIT,
|
|
0, 0);
|
|
input_set_abs_params(input_dev, ABS_Y,
|
|
pdata->y_min ? : 0,
|
|
pdata->y_max ? : MAX_12BIT,
|
|
0, 0);
|
|
input_set_abs_params(input_dev, ABS_PRESSURE,
|
|
pdata->pressure_min, pdata->pressure_max, 0, 0);
|
|
|
|
vref = pdata->keep_vref_on;
|
|
|
|
/* set up the transfers to read touchscreen state; this assumes we
|
|
* use formula #2 for pressure, not #3.
|
|
*/
|
|
m = &ts->msg[0];
|
|
x = ts->xfer;
|
|
|
|
spi_message_init(m);
|
|
|
|
/* y- still on; turn on only y+ (and ADC) */
|
|
packet->read_y = READ_Y(vref);
|
|
x->tx_buf = &packet->read_y;
|
|
x->len = 1;
|
|
spi_message_add_tail(x, m);
|
|
|
|
x++;
|
|
x->rx_buf = &packet->tc.y;
|
|
x->len = 2;
|
|
spi_message_add_tail(x, m);
|
|
|
|
/* the first sample after switching drivers can be low quality;
|
|
* optionally discard it, using a second one after the signals
|
|
* have had enough time to stabilize.
|
|
*/
|
|
if (pdata->settle_delay_usecs) {
|
|
x->delay_usecs = pdata->settle_delay_usecs;
|
|
|
|
x++;
|
|
x->tx_buf = &packet->read_y;
|
|
x->len = 1;
|
|
spi_message_add_tail(x, m);
|
|
|
|
x++;
|
|
x->rx_buf = &packet->tc.y;
|
|
x->len = 2;
|
|
spi_message_add_tail(x, m);
|
|
}
|
|
|
|
m->complete = ads7846_rx_val;
|
|
m->context = ts;
|
|
|
|
m++;
|
|
spi_message_init(m);
|
|
|
|
/* turn y- off, x+ on, then leave in lowpower */
|
|
x++;
|
|
packet->read_x = READ_X(vref);
|
|
x->tx_buf = &packet->read_x;
|
|
x->len = 1;
|
|
spi_message_add_tail(x, m);
|
|
|
|
x++;
|
|
x->rx_buf = &packet->tc.x;
|
|
x->len = 2;
|
|
spi_message_add_tail(x, m);
|
|
|
|
/* ... maybe discard first sample ... */
|
|
if (pdata->settle_delay_usecs) {
|
|
x->delay_usecs = pdata->settle_delay_usecs;
|
|
|
|
x++;
|
|
x->tx_buf = &packet->read_x;
|
|
x->len = 1;
|
|
spi_message_add_tail(x, m);
|
|
|
|
x++;
|
|
x->rx_buf = &packet->tc.x;
|
|
x->len = 2;
|
|
spi_message_add_tail(x, m);
|
|
}
|
|
|
|
m->complete = ads7846_rx_val;
|
|
m->context = ts;
|
|
|
|
/* turn y+ off, x- on; we'll use formula #2 */
|
|
if (ts->model == 7846) {
|
|
m++;
|
|
spi_message_init(m);
|
|
|
|
x++;
|
|
packet->read_z1 = READ_Z1(vref);
|
|
x->tx_buf = &packet->read_z1;
|
|
x->len = 1;
|
|
spi_message_add_tail(x, m);
|
|
|
|
x++;
|
|
x->rx_buf = &packet->tc.z1;
|
|
x->len = 2;
|
|
spi_message_add_tail(x, m);
|
|
|
|
/* ... maybe discard first sample ... */
|
|
if (pdata->settle_delay_usecs) {
|
|
x->delay_usecs = pdata->settle_delay_usecs;
|
|
|
|
x++;
|
|
x->tx_buf = &packet->read_z1;
|
|
x->len = 1;
|
|
spi_message_add_tail(x, m);
|
|
|
|
x++;
|
|
x->rx_buf = &packet->tc.z1;
|
|
x->len = 2;
|
|
spi_message_add_tail(x, m);
|
|
}
|
|
|
|
m->complete = ads7846_rx_val;
|
|
m->context = ts;
|
|
|
|
m++;
|
|
spi_message_init(m);
|
|
|
|
x++;
|
|
packet->read_z2 = READ_Z2(vref);
|
|
x->tx_buf = &packet->read_z2;
|
|
x->len = 1;
|
|
spi_message_add_tail(x, m);
|
|
|
|
x++;
|
|
x->rx_buf = &packet->tc.z2;
|
|
x->len = 2;
|
|
spi_message_add_tail(x, m);
|
|
|
|
/* ... maybe discard first sample ... */
|
|
if (pdata->settle_delay_usecs) {
|
|
x->delay_usecs = pdata->settle_delay_usecs;
|
|
|
|
x++;
|
|
x->tx_buf = &packet->read_z2;
|
|
x->len = 1;
|
|
spi_message_add_tail(x, m);
|
|
|
|
x++;
|
|
x->rx_buf = &packet->tc.z2;
|
|
x->len = 2;
|
|
spi_message_add_tail(x, m);
|
|
}
|
|
|
|
m->complete = ads7846_rx_val;
|
|
m->context = ts;
|
|
}
|
|
|
|
/* power down */
|
|
m++;
|
|
spi_message_init(m);
|
|
|
|
x++;
|
|
packet->pwrdown = PWRDOWN;
|
|
x->tx_buf = &packet->pwrdown;
|
|
x->len = 1;
|
|
spi_message_add_tail(x, m);
|
|
|
|
x++;
|
|
x->rx_buf = &packet->dummy;
|
|
x->len = 2;
|
|
CS_CHANGE(*x);
|
|
spi_message_add_tail(x, m);
|
|
|
|
m->complete = ads7846_rx;
|
|
m->context = ts;
|
|
|
|
ts->last_msg = m;
|
|
|
|
if (request_irq(spi->irq, ads7846_irq, IRQF_TRIGGER_FALLING,
|
|
spi->dev.driver->name, ts)) {
|
|
dev_info(&spi->dev,
|
|
"trying pin change workaround on irq %d\n", spi->irq);
|
|
err = request_irq(spi->irq, ads7846_irq,
|
|
IRQF_TRIGGER_FALLING | IRQF_TRIGGER_RISING,
|
|
spi->dev.driver->name, ts);
|
|
if (err) {
|
|
dev_dbg(&spi->dev, "irq %d busy?\n", spi->irq);
|
|
goto err_free_gpio;
|
|
}
|
|
}
|
|
|
|
err = ads784x_hwmon_register(spi, ts);
|
|
if (err)
|
|
goto err_free_irq;
|
|
|
|
dev_info(&spi->dev, "touchscreen, irq %d\n", spi->irq);
|
|
|
|
/* take a first sample, leaving nPENIRQ active and vREF off; avoid
|
|
* the touchscreen, in case it's not connected.
|
|
*/
|
|
(void) ads7846_read12_ser(&spi->dev,
|
|
READ_12BIT_SER(vaux) | ADS_PD10_ALL_ON);
|
|
|
|
err = sysfs_create_group(&spi->dev.kobj, &ads784x_attr_group);
|
|
if (err)
|
|
goto err_remove_hwmon;
|
|
|
|
err = input_register_device(input_dev);
|
|
if (err)
|
|
goto err_remove_attr_group;
|
|
|
|
return 0;
|
|
|
|
err_remove_attr_group:
|
|
sysfs_remove_group(&spi->dev.kobj, &ads784x_attr_group);
|
|
err_remove_hwmon:
|
|
ads784x_hwmon_unregister(spi, ts);
|
|
err_free_irq:
|
|
free_irq(spi->irq, ts);
|
|
err_free_gpio:
|
|
if (ts->gpio_pendown != -1)
|
|
gpio_free(ts->gpio_pendown);
|
|
err_cleanup_filter:
|
|
if (ts->filter_cleanup)
|
|
ts->filter_cleanup(ts->filter_data);
|
|
err_free_mem:
|
|
input_free_device(input_dev);
|
|
kfree(packet);
|
|
kfree(ts);
|
|
return err;
|
|
}
|
|
|
|
static int __devexit ads7846_remove(struct spi_device *spi)
|
|
{
|
|
struct ads7846 *ts = dev_get_drvdata(&spi->dev);
|
|
|
|
ads784x_hwmon_unregister(spi, ts);
|
|
input_unregister_device(ts->input);
|
|
|
|
ads7846_suspend(spi, PMSG_SUSPEND);
|
|
|
|
sysfs_remove_group(&spi->dev.kobj, &ads784x_attr_group);
|
|
|
|
free_irq(ts->spi->irq, ts);
|
|
/* suspend left the IRQ disabled */
|
|
enable_irq(ts->spi->irq);
|
|
|
|
if (ts->gpio_pendown != -1)
|
|
gpio_free(ts->gpio_pendown);
|
|
|
|
if (ts->filter_cleanup)
|
|
ts->filter_cleanup(ts->filter_data);
|
|
|
|
kfree(ts->packet);
|
|
kfree(ts);
|
|
|
|
dev_dbg(&spi->dev, "unregistered touchscreen\n");
|
|
return 0;
|
|
}
|
|
|
|
static struct spi_driver ads7846_driver = {
|
|
.driver = {
|
|
.name = "ads7846",
|
|
.bus = &spi_bus_type,
|
|
.owner = THIS_MODULE,
|
|
},
|
|
.probe = ads7846_probe,
|
|
.remove = __devexit_p(ads7846_remove),
|
|
.suspend = ads7846_suspend,
|
|
.resume = ads7846_resume,
|
|
};
|
|
|
|
static int __init ads7846_init(void)
|
|
{
|
|
return spi_register_driver(&ads7846_driver);
|
|
}
|
|
module_init(ads7846_init);
|
|
|
|
static void __exit ads7846_exit(void)
|
|
{
|
|
spi_unregister_driver(&ads7846_driver);
|
|
}
|
|
module_exit(ads7846_exit);
|
|
|
|
MODULE_DESCRIPTION("ADS7846 TouchScreen Driver");
|
|
MODULE_LICENSE("GPL");
|
|
MODULE_ALIAS("spi:ads7846");
|