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linux/drivers/spi/amba-pl022.c

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/*
* drivers/spi/amba-pl022.c
*
* A driver for the ARM PL022 PrimeCell SSP/SPI bus master.
*
* Copyright (C) 2008-2009 ST-Ericsson AB
* Copyright (C) 2006 STMicroelectronics Pvt. Ltd.
*
* Author: Linus Walleij <linus.walleij@stericsson.com>
*
* Initial version inspired by:
* linux-2.6.17-rc3-mm1/drivers/spi/pxa2xx_spi.c
* Initial adoption to PL022 by:
* Sachin Verma <sachin.verma@st.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
/*
* TODO:
* - add timeout on polled transfers
* - add generic DMA framework support
*/
#include <linux/init.h>
#include <linux/module.h>
#include <linux/device.h>
#include <linux/ioport.h>
#include <linux/errno.h>
#include <linux/interrupt.h>
#include <linux/spi/spi.h>
#include <linux/workqueue.h>
#include <linux/errno.h>
#include <linux/delay.h>
#include <linux/clk.h>
#include <linux/err.h>
#include <linux/amba/bus.h>
#include <linux/amba/pl022.h>
#include <linux/io.h>
#include <linux/delay.h>
/*
* This macro is used to define some register default values.
* reg is masked with mask, the OR:ed with an (again masked)
* val shifted sb steps to the left.
*/
#define SSP_WRITE_BITS(reg, val, mask, sb) \
((reg) = (((reg) & ~(mask)) | (((val)<<(sb)) & (mask))))
/*
* This macro is also used to define some default values.
* It will just shift val by sb steps to the left and mask
* the result with mask.
*/
#define GEN_MASK_BITS(val, mask, sb) \
(((val)<<(sb)) & (mask))
#define DRIVE_TX 0
#define DO_NOT_DRIVE_TX 1
#define DO_NOT_QUEUE_DMA 0
#define QUEUE_DMA 1
#define RX_TRANSFER 1
#define TX_TRANSFER 2
/*
* Macros to access SSP Registers with their offsets
*/
#define SSP_CR0(r) (r + 0x000)
#define SSP_CR1(r) (r + 0x004)
#define SSP_DR(r) (r + 0x008)
#define SSP_SR(r) (r + 0x00C)
#define SSP_CPSR(r) (r + 0x010)
#define SSP_IMSC(r) (r + 0x014)
#define SSP_RIS(r) (r + 0x018)
#define SSP_MIS(r) (r + 0x01C)
#define SSP_ICR(r) (r + 0x020)
#define SSP_DMACR(r) (r + 0x024)
#define SSP_ITCR(r) (r + 0x080)
#define SSP_ITIP(r) (r + 0x084)
#define SSP_ITOP(r) (r + 0x088)
#define SSP_TDR(r) (r + 0x08C)
#define SSP_PID0(r) (r + 0xFE0)
#define SSP_PID1(r) (r + 0xFE4)
#define SSP_PID2(r) (r + 0xFE8)
#define SSP_PID3(r) (r + 0xFEC)
#define SSP_CID0(r) (r + 0xFF0)
#define SSP_CID1(r) (r + 0xFF4)
#define SSP_CID2(r) (r + 0xFF8)
#define SSP_CID3(r) (r + 0xFFC)
/*
* SSP Control Register 0 - SSP_CR0
*/
#define SSP_CR0_MASK_DSS (0x1FUL << 0)
#define SSP_CR0_MASK_HALFDUP (0x1UL << 5)
#define SSP_CR0_MASK_SPO (0x1UL << 6)
#define SSP_CR0_MASK_SPH (0x1UL << 7)
#define SSP_CR0_MASK_SCR (0xFFUL << 8)
#define SSP_CR0_MASK_CSS (0x1FUL << 16)
#define SSP_CR0_MASK_FRF (0x3UL << 21)
/*
* SSP Control Register 0 - SSP_CR1
*/
#define SSP_CR1_MASK_LBM (0x1UL << 0)
#define SSP_CR1_MASK_SSE (0x1UL << 1)
#define SSP_CR1_MASK_MS (0x1UL << 2)
#define SSP_CR1_MASK_SOD (0x1UL << 3)
#define SSP_CR1_MASK_RENDN (0x1UL << 4)
#define SSP_CR1_MASK_TENDN (0x1UL << 5)
#define SSP_CR1_MASK_MWAIT (0x1UL << 6)
#define SSP_CR1_MASK_RXIFLSEL (0x7UL << 7)
#define SSP_CR1_MASK_TXIFLSEL (0x7UL << 10)
/*
* SSP Data Register - SSP_DR
*/
#define SSP_DR_MASK_DATA 0xFFFFFFFF
/*
* SSP Status Register - SSP_SR
*/
#define SSP_SR_MASK_TFE (0x1UL << 0) /* Transmit FIFO empty */
#define SSP_SR_MASK_TNF (0x1UL << 1) /* Transmit FIFO not full */
#define SSP_SR_MASK_RNE (0x1UL << 2) /* Receive FIFO not empty */
#define SSP_SR_MASK_RFF (0x1UL << 3) /* Receive FIFO full */
#define SSP_SR_MASK_BSY (0x1UL << 4) /* Busy Flag */
/*
* SSP Clock Prescale Register - SSP_CPSR
*/
#define SSP_CPSR_MASK_CPSDVSR (0xFFUL << 0)
/*
* SSP Interrupt Mask Set/Clear Register - SSP_IMSC
*/
#define SSP_IMSC_MASK_RORIM (0x1UL << 0) /* Receive Overrun Interrupt mask */
#define SSP_IMSC_MASK_RTIM (0x1UL << 1) /* Receive timeout Interrupt mask */
#define SSP_IMSC_MASK_RXIM (0x1UL << 2) /* Receive FIFO Interrupt mask */
#define SSP_IMSC_MASK_TXIM (0x1UL << 3) /* Transmit FIFO Interrupt mask */
/*
* SSP Raw Interrupt Status Register - SSP_RIS
*/
/* Receive Overrun Raw Interrupt status */
#define SSP_RIS_MASK_RORRIS (0x1UL << 0)
/* Receive Timeout Raw Interrupt status */
#define SSP_RIS_MASK_RTRIS (0x1UL << 1)
/* Receive FIFO Raw Interrupt status */
#define SSP_RIS_MASK_RXRIS (0x1UL << 2)
/* Transmit FIFO Raw Interrupt status */
#define SSP_RIS_MASK_TXRIS (0x1UL << 3)
/*
* SSP Masked Interrupt Status Register - SSP_MIS
*/
/* Receive Overrun Masked Interrupt status */
#define SSP_MIS_MASK_RORMIS (0x1UL << 0)
/* Receive Timeout Masked Interrupt status */
#define SSP_MIS_MASK_RTMIS (0x1UL << 1)
/* Receive FIFO Masked Interrupt status */
#define SSP_MIS_MASK_RXMIS (0x1UL << 2)
/* Transmit FIFO Masked Interrupt status */
#define SSP_MIS_MASK_TXMIS (0x1UL << 3)
/*
* SSP Interrupt Clear Register - SSP_ICR
*/
/* Receive Overrun Raw Clear Interrupt bit */
#define SSP_ICR_MASK_RORIC (0x1UL << 0)
/* Receive Timeout Clear Interrupt bit */
#define SSP_ICR_MASK_RTIC (0x1UL << 1)
/*
* SSP DMA Control Register - SSP_DMACR
*/
/* Receive DMA Enable bit */
#define SSP_DMACR_MASK_RXDMAE (0x1UL << 0)
/* Transmit DMA Enable bit */
#define SSP_DMACR_MASK_TXDMAE (0x1UL << 1)
/*
* SSP Integration Test control Register - SSP_ITCR
*/
#define SSP_ITCR_MASK_ITEN (0x1UL << 0)
#define SSP_ITCR_MASK_TESTFIFO (0x1UL << 1)
/*
* SSP Integration Test Input Register - SSP_ITIP
*/
#define ITIP_MASK_SSPRXD (0x1UL << 0)
#define ITIP_MASK_SSPFSSIN (0x1UL << 1)
#define ITIP_MASK_SSPCLKIN (0x1UL << 2)
#define ITIP_MASK_RXDMAC (0x1UL << 3)
#define ITIP_MASK_TXDMAC (0x1UL << 4)
#define ITIP_MASK_SSPTXDIN (0x1UL << 5)
/*
* SSP Integration Test output Register - SSP_ITOP
*/
#define ITOP_MASK_SSPTXD (0x1UL << 0)
#define ITOP_MASK_SSPFSSOUT (0x1UL << 1)
#define ITOP_MASK_SSPCLKOUT (0x1UL << 2)
#define ITOP_MASK_SSPOEn (0x1UL << 3)
#define ITOP_MASK_SSPCTLOEn (0x1UL << 4)
#define ITOP_MASK_RORINTR (0x1UL << 5)
#define ITOP_MASK_RTINTR (0x1UL << 6)
#define ITOP_MASK_RXINTR (0x1UL << 7)
#define ITOP_MASK_TXINTR (0x1UL << 8)
#define ITOP_MASK_INTR (0x1UL << 9)
#define ITOP_MASK_RXDMABREQ (0x1UL << 10)
#define ITOP_MASK_RXDMASREQ (0x1UL << 11)
#define ITOP_MASK_TXDMABREQ (0x1UL << 12)
#define ITOP_MASK_TXDMASREQ (0x1UL << 13)
/*
* SSP Test Data Register - SSP_TDR
*/
#define TDR_MASK_TESTDATA (0xFFFFFFFF)
/*
* Message State
* we use the spi_message.state (void *) pointer to
* hold a single state value, that's why all this
* (void *) casting is done here.
*/
#define STATE_START ((void *) 0)
#define STATE_RUNNING ((void *) 1)
#define STATE_DONE ((void *) 2)
#define STATE_ERROR ((void *) -1)
/*
* Queue State
*/
#define QUEUE_RUNNING (0)
#define QUEUE_STOPPED (1)
/*
* SSP State - Whether Enabled or Disabled
*/
#define SSP_DISABLED (0)
#define SSP_ENABLED (1)
/*
* SSP DMA State - Whether DMA Enabled or Disabled
*/
#define SSP_DMA_DISABLED (0)
#define SSP_DMA_ENABLED (1)
/*
* SSP Clock Defaults
*/
#define NMDK_SSP_DEFAULT_CLKRATE 0x2
#define NMDK_SSP_DEFAULT_PRESCALE 0x40
/*
* SSP Clock Parameter ranges
*/
#define CPSDVR_MIN 0x02
#define CPSDVR_MAX 0xFE
#define SCR_MIN 0x00
#define SCR_MAX 0xFF
/*
* SSP Interrupt related Macros
*/
#define DEFAULT_SSP_REG_IMSC 0x0UL
#define DISABLE_ALL_INTERRUPTS DEFAULT_SSP_REG_IMSC
#define ENABLE_ALL_INTERRUPTS (~DEFAULT_SSP_REG_IMSC)
#define CLEAR_ALL_INTERRUPTS 0x3
/*
* The type of reading going on on this chip
*/
enum ssp_reading {
READING_NULL,
READING_U8,
READING_U16,
READING_U32
};
/**
* The type of writing going on on this chip
*/
enum ssp_writing {
WRITING_NULL,
WRITING_U8,
WRITING_U16,
WRITING_U32
};
/**
* struct vendor_data - vendor-specific config parameters
* for PL022 derivates
* @fifodepth: depth of FIFOs (both)
* @max_bpw: maximum number of bits per word
* @unidir: supports unidirection transfers
*/
struct vendor_data {
int fifodepth;
int max_bpw;
bool unidir;
};
/**
* struct pl022 - This is the private SSP driver data structure
* @adev: AMBA device model hookup
* @phybase: The physical memory where the SSP device resides
* @virtbase: The virtual memory where the SSP is mapped
* @master: SPI framework hookup
* @master_info: controller-specific data from machine setup
* @regs: SSP controller register's virtual address
* @pump_messages: Work struct for scheduling work to the workqueue
* @lock: spinlock to syncronise access to driver data
* @workqueue: a workqueue on which any spi_message request is queued
* @busy: workqueue is busy
* @run: workqueue is running
* @pump_transfers: Tasklet used in Interrupt Transfer mode
* @cur_msg: Pointer to current spi_message being processed
* @cur_transfer: Pointer to current spi_transfer
* @cur_chip: pointer to current clients chip(assigned from controller_state)
* @tx: current position in TX buffer to be read
* @tx_end: end position in TX buffer to be read
* @rx: current position in RX buffer to be written
* @rx_end: end position in RX buffer to be written
* @readingtype: the type of read currently going on
* @writingtype: the type or write currently going on
*/
struct pl022 {
struct amba_device *adev;
struct vendor_data *vendor;
resource_size_t phybase;
void __iomem *virtbase;
struct clk *clk;
struct spi_master *master;
struct pl022_ssp_controller *master_info;
/* Driver message queue */
struct workqueue_struct *workqueue;
struct work_struct pump_messages;
spinlock_t queue_lock;
struct list_head queue;
int busy;
int run;
/* Message transfer pump */
struct tasklet_struct pump_transfers;
struct spi_message *cur_msg;
struct spi_transfer *cur_transfer;
struct chip_data *cur_chip;
void *tx;
void *tx_end;
void *rx;
void *rx_end;
enum ssp_reading read;
enum ssp_writing write;
};
/**
* struct chip_data - To maintain runtime state of SSP for each client chip
* @cr0: Value of control register CR0 of SSP
* @cr1: Value of control register CR1 of SSP
* @dmacr: Value of DMA control Register of SSP
* @cpsr: Value of Clock prescale register
* @n_bytes: how many bytes(power of 2) reqd for a given data width of client
* @enable_dma: Whether to enable DMA or not
* @write: function ptr to be used to write when doing xfer for this chip
* @read: function ptr to be used to read when doing xfer for this chip
* @cs_control: chip select callback provided by chip
* @xfer_type: polling/interrupt/DMA
*
* Runtime state of the SSP controller, maintained per chip,
* This would be set according to the current message that would be served
*/
struct chip_data {
u16 cr0;
u16 cr1;
u16 dmacr;
u16 cpsr;
u8 n_bytes;
u8 enable_dma:1;
enum ssp_reading read;
enum ssp_writing write;
void (*cs_control) (u32 command);
int xfer_type;
};
/**
* null_cs_control - Dummy chip select function
* @command: select/delect the chip
*
* If no chip select function is provided by client this is used as dummy
* chip select
*/
static void null_cs_control(u32 command)
{
pr_debug("pl022: dummy chip select control, CS=0x%x\n", command);
}
/**
* giveback - current spi_message is over, schedule next message and call
* callback of this message. Assumes that caller already
* set message->status; dma and pio irqs are blocked
* @pl022: SSP driver private data structure
*/
static void giveback(struct pl022 *pl022)
{
struct spi_transfer *last_transfer;
unsigned long flags;
struct spi_message *msg;
void (*curr_cs_control) (u32 command);
/*
* This local reference to the chip select function
* is needed because we set curr_chip to NULL
* as a step toward termininating the message.
*/
curr_cs_control = pl022->cur_chip->cs_control;
spin_lock_irqsave(&pl022->queue_lock, flags);
msg = pl022->cur_msg;
pl022->cur_msg = NULL;
pl022->cur_transfer = NULL;
pl022->cur_chip = NULL;
queue_work(pl022->workqueue, &pl022->pump_messages);
spin_unlock_irqrestore(&pl022->queue_lock, flags);
last_transfer = list_entry(msg->transfers.prev,
struct spi_transfer,
transfer_list);
/* Delay if requested before any change in chip select */
if (last_transfer->delay_usecs)
/*
* FIXME: This runs in interrupt context.
* Is this really smart?
*/
udelay(last_transfer->delay_usecs);
/*
* Drop chip select UNLESS cs_change is true or we are returning
* a message with an error, or next message is for another chip
*/
if (!last_transfer->cs_change)
curr_cs_control(SSP_CHIP_DESELECT);
else {
struct spi_message *next_msg;
/* Holding of cs was hinted, but we need to make sure
* the next message is for the same chip. Don't waste
* time with the following tests unless this was hinted.
*
* We cannot postpone this until pump_messages, because
* after calling msg->complete (below) the driver that
* sent the current message could be unloaded, which
* could invalidate the cs_control() callback...
*/
/* get a pointer to the next message, if any */
spin_lock_irqsave(&pl022->queue_lock, flags);
if (list_empty(&pl022->queue))
next_msg = NULL;
else
next_msg = list_entry(pl022->queue.next,
struct spi_message, queue);
spin_unlock_irqrestore(&pl022->queue_lock, flags);
/* see if the next and current messages point
* to the same chip
*/
if (next_msg && next_msg->spi != msg->spi)
next_msg = NULL;
if (!next_msg || msg->state == STATE_ERROR)
curr_cs_control(SSP_CHIP_DESELECT);
}
msg->state = NULL;
if (msg->complete)
msg->complete(msg->context);
/* This message is completed, so let's turn off the clock! */
clk_disable(pl022->clk);
}
/**
* flush - flush the FIFO to reach a clean state
* @pl022: SSP driver private data structure
*/
static int flush(struct pl022 *pl022)
{
unsigned long limit = loops_per_jiffy << 1;
dev_dbg(&pl022->adev->dev, "flush\n");
do {
while (readw(SSP_SR(pl022->virtbase)) & SSP_SR_MASK_RNE)
readw(SSP_DR(pl022->virtbase));
} while ((readw(SSP_SR(pl022->virtbase)) & SSP_SR_MASK_BSY) && limit--);
return limit;
}
/**
* restore_state - Load configuration of current chip
* @pl022: SSP driver private data structure
*/
static void restore_state(struct pl022 *pl022)
{
struct chip_data *chip = pl022->cur_chip;
writew(chip->cr0, SSP_CR0(pl022->virtbase));
writew(chip->cr1, SSP_CR1(pl022->virtbase));
writew(chip->dmacr, SSP_DMACR(pl022->virtbase));
writew(chip->cpsr, SSP_CPSR(pl022->virtbase));
writew(DISABLE_ALL_INTERRUPTS, SSP_IMSC(pl022->virtbase));
writew(CLEAR_ALL_INTERRUPTS, SSP_ICR(pl022->virtbase));
}
/**
* load_ssp_default_config - Load default configuration for SSP
* @pl022: SSP driver private data structure
*/
/*
* Default SSP Register Values
*/
#define DEFAULT_SSP_REG_CR0 ( \
GEN_MASK_BITS(SSP_DATA_BITS_12, SSP_CR0_MASK_DSS, 0) | \
GEN_MASK_BITS(SSP_MICROWIRE_CHANNEL_FULL_DUPLEX, SSP_CR0_MASK_HALFDUP, 5) | \
GEN_MASK_BITS(SSP_CLK_POL_IDLE_LOW, SSP_CR0_MASK_SPO, 6) | \
GEN_MASK_BITS(SSP_CLK_FALLING_EDGE, SSP_CR0_MASK_SPH, 7) | \
GEN_MASK_BITS(NMDK_SSP_DEFAULT_CLKRATE, SSP_CR0_MASK_SCR, 8) | \
GEN_MASK_BITS(SSP_BITS_8, SSP_CR0_MASK_CSS, 16) | \
GEN_MASK_BITS(SSP_INTERFACE_MOTOROLA_SPI, SSP_CR0_MASK_FRF, 21) \
)
#define DEFAULT_SSP_REG_CR1 ( \
GEN_MASK_BITS(LOOPBACK_DISABLED, SSP_CR1_MASK_LBM, 0) | \
GEN_MASK_BITS(SSP_DISABLED, SSP_CR1_MASK_SSE, 1) | \
GEN_MASK_BITS(SSP_MASTER, SSP_CR1_MASK_MS, 2) | \
GEN_MASK_BITS(DO_NOT_DRIVE_TX, SSP_CR1_MASK_SOD, 3) | \
GEN_MASK_BITS(SSP_RX_MSB, SSP_CR1_MASK_RENDN, 4) | \
GEN_MASK_BITS(SSP_TX_MSB, SSP_CR1_MASK_TENDN, 5) | \
GEN_MASK_BITS(SSP_MWIRE_WAIT_ZERO, SSP_CR1_MASK_MWAIT, 6) |\
GEN_MASK_BITS(SSP_RX_1_OR_MORE_ELEM, SSP_CR1_MASK_RXIFLSEL, 7) | \
GEN_MASK_BITS(SSP_TX_1_OR_MORE_EMPTY_LOC, SSP_CR1_MASK_TXIFLSEL, 10) \
)
#define DEFAULT_SSP_REG_CPSR ( \
GEN_MASK_BITS(NMDK_SSP_DEFAULT_PRESCALE, SSP_CPSR_MASK_CPSDVSR, 0) \
)
#define DEFAULT_SSP_REG_DMACR (\
GEN_MASK_BITS(SSP_DMA_DISABLED, SSP_DMACR_MASK_RXDMAE, 0) | \
GEN_MASK_BITS(SSP_DMA_DISABLED, SSP_DMACR_MASK_TXDMAE, 1) \
)
static void load_ssp_default_config(struct pl022 *pl022)
{
writew(DEFAULT_SSP_REG_CR0, SSP_CR0(pl022->virtbase));
writew(DEFAULT_SSP_REG_CR1, SSP_CR1(pl022->virtbase));
writew(DEFAULT_SSP_REG_DMACR, SSP_DMACR(pl022->virtbase));
writew(DEFAULT_SSP_REG_CPSR, SSP_CPSR(pl022->virtbase));
writew(DISABLE_ALL_INTERRUPTS, SSP_IMSC(pl022->virtbase));
writew(CLEAR_ALL_INTERRUPTS, SSP_ICR(pl022->virtbase));
}
/**
* This will write to TX and read from RX according to the parameters
* set in pl022.
*/
static void readwriter(struct pl022 *pl022)
{
/*
* The FIFO depth is different inbetween primecell variants.
* I believe filling in too much in the FIFO might cause
* errons in 8bit wide transfers on ARM variants (just 8 words
* FIFO, means only 8x8 = 64 bits in FIFO) at least.
*
* FIXME: currently we have no logic to account for this.
* perhaps there is even something broken in HW regarding
* 8bit transfers (it doesn't fail on 16bit) so this needs
* more investigation...
*/
dev_dbg(&pl022->adev->dev,
"%s, rx: %p, rxend: %p, tx: %p, txend: %p\n",
__func__, pl022->rx, pl022->rx_end, pl022->tx, pl022->tx_end);
/* Read as much as you can */
while ((readw(SSP_SR(pl022->virtbase)) & SSP_SR_MASK_RNE)
&& (pl022->rx < pl022->rx_end)) {
switch (pl022->read) {
case READING_NULL:
readw(SSP_DR(pl022->virtbase));
break;
case READING_U8:
*(u8 *) (pl022->rx) =
readw(SSP_DR(pl022->virtbase)) & 0xFFU;
break;
case READING_U16:
*(u16 *) (pl022->rx) =
(u16) readw(SSP_DR(pl022->virtbase));
break;
case READING_U32:
*(u32 *) (pl022->rx) =
readl(SSP_DR(pl022->virtbase));
break;
}
pl022->rx += (pl022->cur_chip->n_bytes);
}
/*
* Write as much as you can, while keeping an eye on the RX FIFO!
*/
while ((readw(SSP_SR(pl022->virtbase)) & SSP_SR_MASK_TNF)
&& (pl022->tx < pl022->tx_end)) {
switch (pl022->write) {
case WRITING_NULL:
writew(0x0, SSP_DR(pl022->virtbase));
break;
case WRITING_U8:
writew(*(u8 *) (pl022->tx), SSP_DR(pl022->virtbase));
break;
case WRITING_U16:
writew((*(u16 *) (pl022->tx)), SSP_DR(pl022->virtbase));
break;
case WRITING_U32:
writel(*(u32 *) (pl022->tx), SSP_DR(pl022->virtbase));
break;
}
pl022->tx += (pl022->cur_chip->n_bytes);
/*
* This inner reader takes care of things appearing in the RX
* FIFO as we're transmitting. This will happen a lot since the
* clock starts running when you put things into the TX FIFO,
* and then things are continously clocked into the RX FIFO.
*/
while ((readw(SSP_SR(pl022->virtbase)) & SSP_SR_MASK_RNE)
&& (pl022->rx < pl022->rx_end)) {
switch (pl022->read) {
case READING_NULL:
readw(SSP_DR(pl022->virtbase));
break;
case READING_U8:
*(u8 *) (pl022->rx) =
readw(SSP_DR(pl022->virtbase)) & 0xFFU;
break;
case READING_U16:
*(u16 *) (pl022->rx) =
(u16) readw(SSP_DR(pl022->virtbase));
break;
case READING_U32:
*(u32 *) (pl022->rx) =
readl(SSP_DR(pl022->virtbase));
break;
}
pl022->rx += (pl022->cur_chip->n_bytes);
}
}
/*
* When we exit here the TX FIFO should be full and the RX FIFO
* should be empty
*/
}
/**
* next_transfer - Move to the Next transfer in the current spi message
* @pl022: SSP driver private data structure
*
* This function moves though the linked list of spi transfers in the
* current spi message and returns with the state of current spi
* message i.e whether its last transfer is done(STATE_DONE) or
* Next transfer is ready(STATE_RUNNING)
*/
static void *next_transfer(struct pl022 *pl022)
{
struct spi_message *msg = pl022->cur_msg;
struct spi_transfer *trans = pl022->cur_transfer;
/* Move to next transfer */
if (trans->transfer_list.next != &msg->transfers) {
pl022->cur_transfer =
list_entry(trans->transfer_list.next,
struct spi_transfer, transfer_list);
return STATE_RUNNING;
}
return STATE_DONE;
}
/**
* pl022_interrupt_handler - Interrupt handler for SSP controller
*
* This function handles interrupts generated for an interrupt based transfer.
* If a receive overrun (ROR) interrupt is there then we disable SSP, flag the
* current message's state as STATE_ERROR and schedule the tasklet
* pump_transfers which will do the postprocessing of the current message by
* calling giveback(). Otherwise it reads data from RX FIFO till there is no
* more data, and writes data in TX FIFO till it is not full. If we complete
* the transfer we move to the next transfer and schedule the tasklet.
*/
static irqreturn_t pl022_interrupt_handler(int irq, void *dev_id)
{
struct pl022 *pl022 = dev_id;
struct spi_message *msg = pl022->cur_msg;
u16 irq_status = 0;
u16 flag = 0;
if (unlikely(!msg)) {
dev_err(&pl022->adev->dev,
"bad message state in interrupt handler");
/* Never fail */
return IRQ_HANDLED;
}
/* Read the Interrupt Status Register */
irq_status = readw(SSP_MIS(pl022->virtbase));
if (unlikely(!irq_status))
return IRQ_NONE;
/* This handles the error code interrupts */
if (unlikely(irq_status & SSP_MIS_MASK_RORMIS)) {
/*
* Overrun interrupt - bail out since our Data has been
* corrupted
*/
dev_err(&pl022->adev->dev,
"FIFO overrun\n");
if (readw(SSP_SR(pl022->virtbase)) & SSP_SR_MASK_RFF)
dev_err(&pl022->adev->dev,
"RXFIFO is full\n");
if (readw(SSP_SR(pl022->virtbase)) & SSP_SR_MASK_TNF)
dev_err(&pl022->adev->dev,
"TXFIFO is full\n");
/*
* Disable and clear interrupts, disable SSP,
* mark message with bad status so it can be
* retried.
*/
writew(DISABLE_ALL_INTERRUPTS,
SSP_IMSC(pl022->virtbase));
writew(CLEAR_ALL_INTERRUPTS, SSP_ICR(pl022->virtbase));
writew((readw(SSP_CR1(pl022->virtbase)) &
(~SSP_CR1_MASK_SSE)), SSP_CR1(pl022->virtbase));
msg->state = STATE_ERROR;
/* Schedule message queue handler */
tasklet_schedule(&pl022->pump_transfers);
return IRQ_HANDLED;
}
readwriter(pl022);
if ((pl022->tx == pl022->tx_end) && (flag == 0)) {
flag = 1;
/* Disable Transmit interrupt */
writew(readw(SSP_IMSC(pl022->virtbase)) &
(~SSP_IMSC_MASK_TXIM),
SSP_IMSC(pl022->virtbase));
}
/*
* Since all transactions must write as much as shall be read,
* we can conclude the entire transaction once RX is complete.
* At this point, all TX will always be finished.
*/
if (pl022->rx >= pl022->rx_end) {
writew(DISABLE_ALL_INTERRUPTS,
SSP_IMSC(pl022->virtbase));
writew(CLEAR_ALL_INTERRUPTS, SSP_ICR(pl022->virtbase));
if (unlikely(pl022->rx > pl022->rx_end)) {
dev_warn(&pl022->adev->dev, "read %u surplus "
"bytes (did you request an odd "
"number of bytes on a 16bit bus?)\n",
(u32) (pl022->rx - pl022->rx_end));
}
/* Update total bytes transfered */
msg->actual_length += pl022->cur_transfer->len;
if (pl022->cur_transfer->cs_change)
pl022->cur_chip->
cs_control(SSP_CHIP_DESELECT);
/* Move to next transfer */
msg->state = next_transfer(pl022);
tasklet_schedule(&pl022->pump_transfers);
return IRQ_HANDLED;
}
return IRQ_HANDLED;
}
/**
* This sets up the pointers to memory for the next message to
* send out on the SPI bus.
*/
static int set_up_next_transfer(struct pl022 *pl022,
struct spi_transfer *transfer)
{
int residue;
/* Sanity check the message for this bus width */
residue = pl022->cur_transfer->len % pl022->cur_chip->n_bytes;
if (unlikely(residue != 0)) {
dev_err(&pl022->adev->dev,
"message of %u bytes to transmit but the current "
"chip bus has a data width of %u bytes!\n",
pl022->cur_transfer->len,
pl022->cur_chip->n_bytes);
dev_err(&pl022->adev->dev, "skipping this message\n");
return -EIO;
}
pl022->tx = (void *)transfer->tx_buf;
pl022->tx_end = pl022->tx + pl022->cur_transfer->len;
pl022->rx = (void *)transfer->rx_buf;
pl022->rx_end = pl022->rx + pl022->cur_transfer->len;
pl022->write =
pl022->tx ? pl022->cur_chip->write : WRITING_NULL;
pl022->read = pl022->rx ? pl022->cur_chip->read : READING_NULL;
return 0;
}
/**
* pump_transfers - Tasklet function which schedules next interrupt transfer
* when running in interrupt transfer mode.
* @data: SSP driver private data structure
*
*/
static void pump_transfers(unsigned long data)
{
struct pl022 *pl022 = (struct pl022 *) data;
struct spi_message *message = NULL;
struct spi_transfer *transfer = NULL;
struct spi_transfer *previous = NULL;
/* Get current state information */
message = pl022->cur_msg;
transfer = pl022->cur_transfer;
/* Handle for abort */
if (message->state == STATE_ERROR) {
message->status = -EIO;
giveback(pl022);
return;
}
/* Handle end of message */
if (message->state == STATE_DONE) {
message->status = 0;
giveback(pl022);
return;
}
/* Delay if requested at end of transfer before CS change */
if (message->state == STATE_RUNNING) {
previous = list_entry(transfer->transfer_list.prev,
struct spi_transfer,
transfer_list);
if (previous->delay_usecs)
/*
* FIXME: This runs in interrupt context.
* Is this really smart?
*/
udelay(previous->delay_usecs);
/* Drop chip select only if cs_change is requested */
if (previous->cs_change)
pl022->cur_chip->cs_control(SSP_CHIP_SELECT);
} else {
/* STATE_START */
message->state = STATE_RUNNING;
}
if (set_up_next_transfer(pl022, transfer)) {
message->state = STATE_ERROR;
message->status = -EIO;
giveback(pl022);
return;
}
/* Flush the FIFOs and let's go! */
flush(pl022);
writew(ENABLE_ALL_INTERRUPTS, SSP_IMSC(pl022->virtbase));
}
/**
* NOT IMPLEMENTED
* configure_dma - It configures the DMA pipes for DMA transfers
* @data: SSP driver's private data structure
*
*/
static int configure_dma(void *data)
{
struct pl022 *pl022 = data;
dev_dbg(&pl022->adev->dev, "configure DMA\n");
return -ENOTSUPP;
}
/**
* do_dma_transfer - It handles transfers of the current message
* if it is DMA xfer.
* NOT FULLY IMPLEMENTED
* @data: SSP driver's private data structure
*/
static void do_dma_transfer(void *data)
{
struct pl022 *pl022 = data;
if (configure_dma(data)) {
dev_dbg(&pl022->adev->dev, "configuration of DMA Failed!\n");
goto err_config_dma;
}
/* TODO: Implememt DMA setup of pipes here */
/* Enable target chip, set up transfer */
pl022->cur_chip->cs_control(SSP_CHIP_SELECT);
if (set_up_next_transfer(pl022, pl022->cur_transfer)) {
/* Error path */
pl022->cur_msg->state = STATE_ERROR;
pl022->cur_msg->status = -EIO;
giveback(pl022);
return;
}
/* Enable SSP */
writew((readw(SSP_CR1(pl022->virtbase)) | SSP_CR1_MASK_SSE),
SSP_CR1(pl022->virtbase));
/* TODO: Enable the DMA transfer here */
return;
err_config_dma:
pl022->cur_msg->state = STATE_ERROR;
pl022->cur_msg->status = -EIO;
giveback(pl022);
return;
}
static void do_interrupt_transfer(void *data)
{
struct pl022 *pl022 = data;
/* Enable target chip */
pl022->cur_chip->cs_control(SSP_CHIP_SELECT);
if (set_up_next_transfer(pl022, pl022->cur_transfer)) {
/* Error path */
pl022->cur_msg->state = STATE_ERROR;
pl022->cur_msg->status = -EIO;
giveback(pl022);
return;
}
/* Enable SSP, turn on interrupts */
writew((readw(SSP_CR1(pl022->virtbase)) | SSP_CR1_MASK_SSE),
SSP_CR1(pl022->virtbase));
writew(ENABLE_ALL_INTERRUPTS, SSP_IMSC(pl022->virtbase));
}
static void do_polling_transfer(void *data)
{
struct pl022 *pl022 = data;
struct spi_message *message = NULL;
struct spi_transfer *transfer = NULL;
struct spi_transfer *previous = NULL;
struct chip_data *chip;
chip = pl022->cur_chip;
message = pl022->cur_msg;
while (message->state != STATE_DONE) {
/* Handle for abort */
if (message->state == STATE_ERROR)
break;
transfer = pl022->cur_transfer;
/* Delay if requested at end of transfer */
if (message->state == STATE_RUNNING) {
previous =
list_entry(transfer->transfer_list.prev,
struct spi_transfer, transfer_list);
if (previous->delay_usecs)
udelay(previous->delay_usecs);
if (previous->cs_change)
pl022->cur_chip->cs_control(SSP_CHIP_SELECT);
} else {
/* STATE_START */
message->state = STATE_RUNNING;
pl022->cur_chip->cs_control(SSP_CHIP_SELECT);
}
/* Configuration Changing Per Transfer */
if (set_up_next_transfer(pl022, transfer)) {
/* Error path */
message->state = STATE_ERROR;
break;
}
/* Flush FIFOs and enable SSP */
flush(pl022);
writew((readw(SSP_CR1(pl022->virtbase)) | SSP_CR1_MASK_SSE),
SSP_CR1(pl022->virtbase));
dev_dbg(&pl022->adev->dev, "POLLING TRANSFER ONGOING ... \n");
/* FIXME: insert a timeout so we don't hang here indefinately */
while (pl022->tx < pl022->tx_end || pl022->rx < pl022->rx_end)
readwriter(pl022);
/* Update total byte transfered */
message->actual_length += pl022->cur_transfer->len;
if (pl022->cur_transfer->cs_change)
pl022->cur_chip->cs_control(SSP_CHIP_DESELECT);
/* Move to next transfer */
message->state = next_transfer(pl022);
}
/* Handle end of message */
if (message->state == STATE_DONE)
message->status = 0;
else
message->status = -EIO;
giveback(pl022);
return;
}
/**
* pump_messages - Workqueue function which processes spi message queue
* @data: pointer to private data of SSP driver
*
* This function checks if there is any spi message in the queue that
* needs processing and delegate control to appropriate function
* do_polling_transfer()/do_interrupt_transfer()/do_dma_transfer()
* based on the kind of the transfer
*
*/
static void pump_messages(struct work_struct *work)
{
struct pl022 *pl022 =
container_of(work, struct pl022, pump_messages);
unsigned long flags;
/* Lock queue and check for queue work */
spin_lock_irqsave(&pl022->queue_lock, flags);
if (list_empty(&pl022->queue) || pl022->run == QUEUE_STOPPED) {
pl022->busy = 0;
spin_unlock_irqrestore(&pl022->queue_lock, flags);
return;
}
/* Make sure we are not already running a message */
if (pl022->cur_msg) {
spin_unlock_irqrestore(&pl022->queue_lock, flags);
return;
}
/* Extract head of queue */
pl022->cur_msg =
list_entry(pl022->queue.next, struct spi_message, queue);
list_del_init(&pl022->cur_msg->queue);
pl022->busy = 1;
spin_unlock_irqrestore(&pl022->queue_lock, flags);
/* Initial message state */
pl022->cur_msg->state = STATE_START;
pl022->cur_transfer = list_entry(pl022->cur_msg->transfers.next,
struct spi_transfer,
transfer_list);
/* Setup the SPI using the per chip configuration */
pl022->cur_chip = spi_get_ctldata(pl022->cur_msg->spi);
/*
* We enable the clock here, then the clock will be disabled when
* giveback() is called in each method (poll/interrupt/DMA)
*/
clk_enable(pl022->clk);
restore_state(pl022);
flush(pl022);
if (pl022->cur_chip->xfer_type == POLLING_TRANSFER)
do_polling_transfer(pl022);
else if (pl022->cur_chip->xfer_type == INTERRUPT_TRANSFER)
do_interrupt_transfer(pl022);
else
do_dma_transfer(pl022);
}
static int __init init_queue(struct pl022 *pl022)
{
INIT_LIST_HEAD(&pl022->queue);
spin_lock_init(&pl022->queue_lock);
pl022->run = QUEUE_STOPPED;
pl022->busy = 0;
tasklet_init(&pl022->pump_transfers,
pump_transfers, (unsigned long)pl022);
INIT_WORK(&pl022->pump_messages, pump_messages);
pl022->workqueue = create_singlethread_workqueue(
dev_name(pl022->master->dev.parent));
if (pl022->workqueue == NULL)
return -EBUSY;
return 0;
}
static int start_queue(struct pl022 *pl022)
{
unsigned long flags;
spin_lock_irqsave(&pl022->queue_lock, flags);
if (pl022->run == QUEUE_RUNNING || pl022->busy) {
spin_unlock_irqrestore(&pl022->queue_lock, flags);
return -EBUSY;
}
pl022->run = QUEUE_RUNNING;
pl022->cur_msg = NULL;
pl022->cur_transfer = NULL;
pl022->cur_chip = NULL;
spin_unlock_irqrestore(&pl022->queue_lock, flags);
queue_work(pl022->workqueue, &pl022->pump_messages);
return 0;
}
static int stop_queue(struct pl022 *pl022)
{
unsigned long flags;
unsigned limit = 500;
int status = 0;
spin_lock_irqsave(&pl022->queue_lock, flags);
/* This is a bit lame, but is optimized for the common execution path.
* A wait_queue on the pl022->busy could be used, but then the common
* execution path (pump_messages) would be required to call wake_up or
* friends on every SPI message. Do this instead */
pl022->run = QUEUE_STOPPED;
while (!list_empty(&pl022->queue) && pl022->busy && limit--) {
spin_unlock_irqrestore(&pl022->queue_lock, flags);
msleep(10);
spin_lock_irqsave(&pl022->queue_lock, flags);
}
if (!list_empty(&pl022->queue) || pl022->busy)
status = -EBUSY;
spin_unlock_irqrestore(&pl022->queue_lock, flags);
return status;
}
static int destroy_queue(struct pl022 *pl022)
{
int status;
status = stop_queue(pl022);
/* we are unloading the module or failing to load (only two calls
* to this routine), and neither call can handle a return value.
* However, destroy_workqueue calls flush_workqueue, and that will
* block until all work is done. If the reason that stop_queue
* timed out is that the work will never finish, then it does no
* good to call destroy_workqueue, so return anyway. */
if (status != 0)
return status;
destroy_workqueue(pl022->workqueue);
return 0;
}
static int verify_controller_parameters(struct pl022 *pl022,
struct pl022_config_chip *chip_info)
{
if ((chip_info->lbm != LOOPBACK_ENABLED)
&& (chip_info->lbm != LOOPBACK_DISABLED)) {
dev_err(chip_info->dev,
"loopback Mode is configured incorrectly\n");
return -EINVAL;
}
if ((chip_info->iface < SSP_INTERFACE_MOTOROLA_SPI)
|| (chip_info->iface > SSP_INTERFACE_UNIDIRECTIONAL)) {
dev_err(chip_info->dev,
"interface is configured incorrectly\n");
return -EINVAL;
}
if ((chip_info->iface == SSP_INTERFACE_UNIDIRECTIONAL) &&
(!pl022->vendor->unidir)) {
dev_err(chip_info->dev,
"unidirectional mode not supported in this "
"hardware version\n");
return -EINVAL;
}
if ((chip_info->hierarchy != SSP_MASTER)
&& (chip_info->hierarchy != SSP_SLAVE)) {
dev_err(chip_info->dev,
"hierarchy is configured incorrectly\n");
return -EINVAL;
}
if (((chip_info->clk_freq).cpsdvsr < CPSDVR_MIN)
|| ((chip_info->clk_freq).cpsdvsr > CPSDVR_MAX)) {
dev_err(chip_info->dev,
"cpsdvsr is configured incorrectly\n");
return -EINVAL;
}
if ((chip_info->endian_rx != SSP_RX_MSB)
&& (chip_info->endian_rx != SSP_RX_LSB)) {
dev_err(chip_info->dev,
"RX FIFO endianess is configured incorrectly\n");
return -EINVAL;
}
if ((chip_info->endian_tx != SSP_TX_MSB)
&& (chip_info->endian_tx != SSP_TX_LSB)) {
dev_err(chip_info->dev,
"TX FIFO endianess is configured incorrectly\n");
return -EINVAL;
}
if ((chip_info->data_size < SSP_DATA_BITS_4)
|| (chip_info->data_size > SSP_DATA_BITS_32)) {
dev_err(chip_info->dev,
"DATA Size is configured incorrectly\n");
return -EINVAL;
}
if ((chip_info->com_mode != INTERRUPT_TRANSFER)
&& (chip_info->com_mode != DMA_TRANSFER)
&& (chip_info->com_mode != POLLING_TRANSFER)) {
dev_err(chip_info->dev,
"Communication mode is configured incorrectly\n");
return -EINVAL;
}
if ((chip_info->rx_lev_trig < SSP_RX_1_OR_MORE_ELEM)
|| (chip_info->rx_lev_trig > SSP_RX_32_OR_MORE_ELEM)) {
dev_err(chip_info->dev,
"RX FIFO Trigger Level is configured incorrectly\n");
return -EINVAL;
}
if ((chip_info->tx_lev_trig < SSP_TX_1_OR_MORE_EMPTY_LOC)
|| (chip_info->tx_lev_trig > SSP_TX_32_OR_MORE_EMPTY_LOC)) {
dev_err(chip_info->dev,
"TX FIFO Trigger Level is configured incorrectly\n");
return -EINVAL;
}
if (chip_info->iface == SSP_INTERFACE_MOTOROLA_SPI) {
if ((chip_info->clk_phase != SSP_CLK_RISING_EDGE)
&& (chip_info->clk_phase != SSP_CLK_FALLING_EDGE)) {
dev_err(chip_info->dev,
"Clock Phase is configured incorrectly\n");
return -EINVAL;
}
if ((chip_info->clk_pol != SSP_CLK_POL_IDLE_LOW)
&& (chip_info->clk_pol != SSP_CLK_POL_IDLE_HIGH)) {
dev_err(chip_info->dev,
"Clock Polarity is configured incorrectly\n");
return -EINVAL;
}
}
if (chip_info->iface == SSP_INTERFACE_NATIONAL_MICROWIRE) {
if ((chip_info->ctrl_len < SSP_BITS_4)
|| (chip_info->ctrl_len > SSP_BITS_32)) {
dev_err(chip_info->dev,
"CTRL LEN is configured incorrectly\n");
return -EINVAL;
}
if ((chip_info->wait_state != SSP_MWIRE_WAIT_ZERO)
&& (chip_info->wait_state != SSP_MWIRE_WAIT_ONE)) {
dev_err(chip_info->dev,
"Wait State is configured incorrectly\n");
return -EINVAL;
}
if ((chip_info->duplex != SSP_MICROWIRE_CHANNEL_FULL_DUPLEX)
&& (chip_info->duplex !=
SSP_MICROWIRE_CHANNEL_HALF_DUPLEX)) {
dev_err(chip_info->dev,
"DUPLEX is configured incorrectly\n");
return -EINVAL;
}
}
if (chip_info->cs_control == NULL) {
dev_warn(chip_info->dev,
"Chip Select Function is NULL for this chip\n");
chip_info->cs_control = null_cs_control;
}
return 0;
}
/**
* pl022_transfer - transfer function registered to SPI master framework
* @spi: spi device which is requesting transfer
* @msg: spi message which is to handled is queued to driver queue
*
* This function is registered to the SPI framework for this SPI master
* controller. It will queue the spi_message in the queue of driver if
* the queue is not stopped and return.
*/
static int pl022_transfer(struct spi_device *spi, struct spi_message *msg)
{
struct pl022 *pl022 = spi_master_get_devdata(spi->master);
unsigned long flags;
spin_lock_irqsave(&pl022->queue_lock, flags);
if (pl022->run == QUEUE_STOPPED) {
spin_unlock_irqrestore(&pl022->queue_lock, flags);
return -ESHUTDOWN;
}
msg->actual_length = 0;
msg->status = -EINPROGRESS;
msg->state = STATE_START;
list_add_tail(&msg->queue, &pl022->queue);
if (pl022->run == QUEUE_RUNNING && !pl022->busy)
queue_work(pl022->workqueue, &pl022->pump_messages);
spin_unlock_irqrestore(&pl022->queue_lock, flags);
return 0;
}
static int calculate_effective_freq(struct pl022 *pl022,
int freq,
struct ssp_clock_params *clk_freq)
{
/* Lets calculate the frequency parameters */
u16 cpsdvsr = 2;
u16 scr = 0;
bool freq_found = false;
u32 rate;
u32 max_tclk;
u32 min_tclk;
rate = clk_get_rate(pl022->clk);
/* cpsdvscr = 2 & scr 0 */
max_tclk = (rate / (CPSDVR_MIN * (1 + SCR_MIN)));
/* cpsdvsr = 254 & scr = 255 */
min_tclk = (rate / (CPSDVR_MAX * (1 + SCR_MAX)));
if ((freq <= max_tclk) && (freq >= min_tclk)) {
while (cpsdvsr <= CPSDVR_MAX && !freq_found) {
while (scr <= SCR_MAX && !freq_found) {
if ((rate /
(cpsdvsr * (1 + scr))) > freq)
scr += 1;
else {
/*
* This bool is made true when
* effective frequency >=
* target frequency is found
*/
freq_found = true;
if ((rate /
(cpsdvsr * (1 + scr))) != freq) {
if (scr == SCR_MIN) {
cpsdvsr -= 2;
scr = SCR_MAX;
} else
scr -= 1;
}
}
}
if (!freq_found) {
cpsdvsr += 2;
scr = SCR_MIN;
}
}
if (cpsdvsr != 0) {
dev_dbg(&pl022->adev->dev,
"SSP Effective Frequency is %u\n",
(rate / (cpsdvsr * (1 + scr))));
clk_freq->cpsdvsr = (u8) (cpsdvsr & 0xFF);
clk_freq->scr = (u8) (scr & 0xFF);
dev_dbg(&pl022->adev->dev,
"SSP cpsdvsr = %d, scr = %d\n",
clk_freq->cpsdvsr, clk_freq->scr);
}
} else {
dev_err(&pl022->adev->dev,
"controller data is incorrect: out of range frequency");
return -EINVAL;
}
return 0;
}
/**
* NOT IMPLEMENTED
* process_dma_info - Processes the DMA info provided by client drivers
* @chip_info: chip info provided by client device
* @chip: Runtime state maintained by the SSP controller for each spi device
*
* This function processes and stores DMA config provided by client driver
* into the runtime state maintained by the SSP controller driver
*/
static int process_dma_info(struct pl022_config_chip *chip_info,
struct chip_data *chip)
{
dev_err(chip_info->dev,
"cannot process DMA info, DMA not implemented!\n");
return -ENOTSUPP;
}
/**
* pl022_setup - setup function registered to SPI master framework
* @spi: spi device which is requesting setup
*
* This function is registered to the SPI framework for this SPI master
* controller. If it is the first time when setup is called by this device,
* this function will initialize the runtime state for this chip and save
* the same in the device structure. Else it will update the runtime info
* with the updated chip info. Nothing is really being written to the
* controller hardware here, that is not done until the actual transfer
* commence.
*/
/* FIXME: JUST GUESSING the spi->mode bits understood by this driver */
#define MODEBITS (SPI_CPOL | SPI_CPHA | SPI_CS_HIGH \
| SPI_LSB_FIRST | SPI_LOOP)
static int pl022_setup(struct spi_device *spi)
{
struct pl022_config_chip *chip_info;
struct chip_data *chip;
int status = 0;
struct pl022 *pl022 = spi_master_get_devdata(spi->master);
if (spi->mode & ~MODEBITS) {
dev_dbg(&spi->dev, "unsupported mode bits %x\n",
spi->mode & ~MODEBITS);
return -EINVAL;
}
if (!spi->max_speed_hz)
return -EINVAL;
/* Get controller_state if one is supplied */
chip = spi_get_ctldata(spi);
if (chip == NULL) {
chip = kzalloc(sizeof(struct chip_data), GFP_KERNEL);
if (!chip) {
dev_err(&spi->dev,
"cannot allocate controller state\n");
return -ENOMEM;
}
dev_dbg(&spi->dev,
"allocated memory for controller's runtime state\n");
}
/* Get controller data if one is supplied */
chip_info = spi->controller_data;
if (chip_info == NULL) {
/* spi_board_info.controller_data not is supplied */
dev_dbg(&spi->dev,
"using default controller_data settings\n");
chip_info =
kzalloc(sizeof(struct pl022_config_chip), GFP_KERNEL);
if (!chip_info) {
dev_err(&spi->dev,
"cannot allocate controller data\n");
status = -ENOMEM;
goto err_first_setup;
}
dev_dbg(&spi->dev, "allocated memory for controller data\n");
/* Pointer back to the SPI device */
chip_info->dev = &spi->dev;
/*
* Set controller data default values:
* Polling is supported by default
*/
chip_info->lbm = LOOPBACK_DISABLED;
chip_info->com_mode = POLLING_TRANSFER;
chip_info->iface = SSP_INTERFACE_MOTOROLA_SPI;
chip_info->hierarchy = SSP_SLAVE;
chip_info->slave_tx_disable = DO_NOT_DRIVE_TX;
chip_info->endian_tx = SSP_TX_LSB;
chip_info->endian_rx = SSP_RX_LSB;
chip_info->data_size = SSP_DATA_BITS_12;
chip_info->rx_lev_trig = SSP_RX_1_OR_MORE_ELEM;
chip_info->tx_lev_trig = SSP_TX_1_OR_MORE_EMPTY_LOC;
chip_info->clk_phase = SSP_CLK_FALLING_EDGE;
chip_info->clk_pol = SSP_CLK_POL_IDLE_LOW;
chip_info->ctrl_len = SSP_BITS_8;
chip_info->wait_state = SSP_MWIRE_WAIT_ZERO;
chip_info->duplex = SSP_MICROWIRE_CHANNEL_FULL_DUPLEX;
chip_info->cs_control = null_cs_control;
} else {
dev_dbg(&spi->dev,
"using user supplied controller_data settings\n");
}
/*
* We can override with custom divisors, else we use the board
* frequency setting
*/
if ((0 == chip_info->clk_freq.cpsdvsr)
&& (0 == chip_info->clk_freq.scr)) {
status = calculate_effective_freq(pl022,
spi->max_speed_hz,
&chip_info->clk_freq);
if (status < 0)
goto err_config_params;
} else {
if ((chip_info->clk_freq.cpsdvsr % 2) != 0)
chip_info->clk_freq.cpsdvsr =
chip_info->clk_freq.cpsdvsr - 1;
}
status = verify_controller_parameters(pl022, chip_info);
if (status) {
dev_err(&spi->dev, "controller data is incorrect");
goto err_config_params;
}
/* Now set controller state based on controller data */
chip->xfer_type = chip_info->com_mode;
chip->cs_control = chip_info->cs_control;
if (chip_info->data_size <= 8) {
dev_dbg(&spi->dev, "1 <= n <=8 bits per word\n");
chip->n_bytes = 1;
chip->read = READING_U8;
chip->write = WRITING_U8;
} else if (chip_info->data_size <= 16) {
dev_dbg(&spi->dev, "9 <= n <= 16 bits per word\n");
chip->n_bytes = 2;
chip->read = READING_U16;
chip->write = WRITING_U16;
} else {
if (pl022->vendor->max_bpw >= 32) {
dev_dbg(&spi->dev, "17 <= n <= 32 bits per word\n");
chip->n_bytes = 4;
chip->read = READING_U32;
chip->write = WRITING_U32;
} else {
dev_err(&spi->dev,
"illegal data size for this controller!\n");
dev_err(&spi->dev,
"a standard pl022 can only handle "
"1 <= n <= 16 bit words\n");
goto err_config_params;
}
}
/* Now Initialize all register settings required for this chip */
chip->cr0 = 0;
chip->cr1 = 0;
chip->dmacr = 0;
chip->cpsr = 0;
if ((chip_info->com_mode == DMA_TRANSFER)
&& ((pl022->master_info)->enable_dma)) {
chip->enable_dma = 1;
dev_dbg(&spi->dev, "DMA mode set in controller state\n");
status = process_dma_info(chip_info, chip);
if (status < 0)
goto err_config_params;
SSP_WRITE_BITS(chip->dmacr, SSP_DMA_ENABLED,
SSP_DMACR_MASK_RXDMAE, 0);
SSP_WRITE_BITS(chip->dmacr, SSP_DMA_ENABLED,
SSP_DMACR_MASK_TXDMAE, 1);
} else {
chip->enable_dma = 0;
dev_dbg(&spi->dev, "DMA mode NOT set in controller state\n");
SSP_WRITE_BITS(chip->dmacr, SSP_DMA_DISABLED,
SSP_DMACR_MASK_RXDMAE, 0);
SSP_WRITE_BITS(chip->dmacr, SSP_DMA_DISABLED,
SSP_DMACR_MASK_TXDMAE, 1);
}
chip->cpsr = chip_info->clk_freq.cpsdvsr;
SSP_WRITE_BITS(chip->cr0, chip_info->data_size, SSP_CR0_MASK_DSS, 0);
SSP_WRITE_BITS(chip->cr0, chip_info->duplex, SSP_CR0_MASK_HALFDUP, 5);
SSP_WRITE_BITS(chip->cr0, chip_info->clk_pol, SSP_CR0_MASK_SPO, 6);
SSP_WRITE_BITS(chip->cr0, chip_info->clk_phase, SSP_CR0_MASK_SPH, 7);
SSP_WRITE_BITS(chip->cr0, chip_info->clk_freq.scr, SSP_CR0_MASK_SCR, 8);
SSP_WRITE_BITS(chip->cr0, chip_info->ctrl_len, SSP_CR0_MASK_CSS, 16);
SSP_WRITE_BITS(chip->cr0, chip_info->iface, SSP_CR0_MASK_FRF, 21);
SSP_WRITE_BITS(chip->cr1, chip_info->lbm, SSP_CR1_MASK_LBM, 0);
SSP_WRITE_BITS(chip->cr1, SSP_DISABLED, SSP_CR1_MASK_SSE, 1);
SSP_WRITE_BITS(chip->cr1, chip_info->hierarchy, SSP_CR1_MASK_MS, 2);
SSP_WRITE_BITS(chip->cr1, chip_info->slave_tx_disable, SSP_CR1_MASK_SOD, 3);
SSP_WRITE_BITS(chip->cr1, chip_info->endian_rx, SSP_CR1_MASK_RENDN, 4);
SSP_WRITE_BITS(chip->cr1, chip_info->endian_tx, SSP_CR1_MASK_TENDN, 5);
SSP_WRITE_BITS(chip->cr1, chip_info->wait_state, SSP_CR1_MASK_MWAIT, 6);
SSP_WRITE_BITS(chip->cr1, chip_info->rx_lev_trig, SSP_CR1_MASK_RXIFLSEL, 7);
SSP_WRITE_BITS(chip->cr1, chip_info->tx_lev_trig, SSP_CR1_MASK_TXIFLSEL, 10);
/* Save controller_state */
spi_set_ctldata(spi, chip);
return status;
err_config_params:
err_first_setup:
kfree(chip);
return status;
}
/**
* pl022_cleanup - cleanup function registered to SPI master framework
* @spi: spi device which is requesting cleanup
*
* This function is registered to the SPI framework for this SPI master
* controller. It will free the runtime state of chip.
*/
static void pl022_cleanup(struct spi_device *spi)
{
struct chip_data *chip = spi_get_ctldata(spi);
spi_set_ctldata(spi, NULL);
kfree(chip);
}
static int __init
pl022_probe(struct amba_device *adev, struct amba_id *id)
{
struct device *dev = &adev->dev;
struct pl022_ssp_controller *platform_info = adev->dev.platform_data;
struct spi_master *master;
struct pl022 *pl022 = NULL; /*Data for this driver */
int status = 0;
dev_info(&adev->dev,
"ARM PL022 driver, device ID: 0x%08x\n", adev->periphid);
if (platform_info == NULL) {
dev_err(&adev->dev, "probe - no platform data supplied\n");
status = -ENODEV;
goto err_no_pdata;
}
/* Allocate master with space for data */
master = spi_alloc_master(dev, sizeof(struct pl022));
if (master == NULL) {
dev_err(&adev->dev, "probe - cannot alloc SPI master\n");
status = -ENOMEM;
goto err_no_master;
}
pl022 = spi_master_get_devdata(master);
pl022->master = master;
pl022->master_info = platform_info;
pl022->adev = adev;
pl022->vendor = id->data;
/*
* Bus Number Which has been Assigned to this SSP controller
* on this board
*/
master->bus_num = platform_info->bus_id;
master->num_chipselect = platform_info->num_chipselect;
master->cleanup = pl022_cleanup;
master->setup = pl022_setup;
master->transfer = pl022_transfer;
dev_dbg(&adev->dev, "BUSNO: %d\n", master->bus_num);
status = amba_request_regions(adev, NULL);
if (status)
goto err_no_ioregion;
pl022->virtbase = ioremap(adev->res.start, resource_size(&adev->res));
if (pl022->virtbase == NULL) {
status = -ENOMEM;
goto err_no_ioremap;
}
printk(KERN_INFO "pl022: mapped registers from 0x%08x to %p\n",
adev->res.start, pl022->virtbase);
pl022->clk = clk_get(&adev->dev, NULL);
if (IS_ERR(pl022->clk)) {
status = PTR_ERR(pl022->clk);
dev_err(&adev->dev, "could not retrieve SSP/SPI bus clock\n");
goto err_no_clk;
}
/* Disable SSP */
clk_enable(pl022->clk);
writew((readw(SSP_CR1(pl022->virtbase)) & (~SSP_CR1_MASK_SSE)),
SSP_CR1(pl022->virtbase));
load_ssp_default_config(pl022);
clk_disable(pl022->clk);
status = request_irq(adev->irq[0], pl022_interrupt_handler, 0, "pl022",
pl022);
if (status < 0) {
dev_err(&adev->dev, "probe - cannot get IRQ (%d)\n", status);
goto err_no_irq;
}
/* Initialize and start queue */
status = init_queue(pl022);
if (status != 0) {
dev_err(&adev->dev, "probe - problem initializing queue\n");
goto err_init_queue;
}
status = start_queue(pl022);
if (status != 0) {
dev_err(&adev->dev, "probe - problem starting queue\n");
goto err_start_queue;
}
/* Register with the SPI framework */
amba_set_drvdata(adev, pl022);
status = spi_register_master(master);
if (status != 0) {
dev_err(&adev->dev,
"probe - problem registering spi master\n");
goto err_spi_register;
}
dev_dbg(dev, "probe succeded\n");
return 0;
err_spi_register:
err_start_queue:
err_init_queue:
destroy_queue(pl022);
free_irq(adev->irq[0], pl022);
err_no_irq:
clk_put(pl022->clk);
err_no_clk:
iounmap(pl022->virtbase);
err_no_ioremap:
amba_release_regions(adev);
err_no_ioregion:
spi_master_put(master);
err_no_master:
err_no_pdata:
return status;
}
static int __exit
pl022_remove(struct amba_device *adev)
{
struct pl022 *pl022 = amba_get_drvdata(adev);
int status = 0;
if (!pl022)
return 0;
/* Remove the queue */
status = destroy_queue(pl022);
if (status != 0) {
dev_err(&adev->dev,
"queue remove failed (%d)\n", status);
return status;
}
load_ssp_default_config(pl022);
free_irq(adev->irq[0], pl022);
clk_disable(pl022->clk);
clk_put(pl022->clk);
iounmap(pl022->virtbase);
amba_release_regions(adev);
tasklet_disable(&pl022->pump_transfers);
spi_unregister_master(pl022->master);
spi_master_put(pl022->master);
amba_set_drvdata(adev, NULL);
dev_dbg(&adev->dev, "remove succeded\n");
return 0;
}
#ifdef CONFIG_PM
static int pl022_suspend(struct amba_device *adev, pm_message_t state)
{
struct pl022 *pl022 = amba_get_drvdata(adev);
int status = 0;
status = stop_queue(pl022);
if (status) {
dev_warn(&adev->dev, "suspend cannot stop queue\n");
return status;
}
clk_enable(pl022->clk);
load_ssp_default_config(pl022);
clk_disable(pl022->clk);
dev_dbg(&adev->dev, "suspended\n");
return 0;
}
static int pl022_resume(struct amba_device *adev)
{
struct pl022 *pl022 = amba_get_drvdata(adev);
int status = 0;
/* Start the queue running */
status = start_queue(pl022);
if (status)
dev_err(&adev->dev, "problem starting queue (%d)\n", status);
else
dev_dbg(&adev->dev, "resumed\n");
return status;
}
#else
#define pl022_suspend NULL
#define pl022_resume NULL
#endif /* CONFIG_PM */
static struct vendor_data vendor_arm = {
.fifodepth = 8,
.max_bpw = 16,
.unidir = false,
};
static struct vendor_data vendor_st = {
.fifodepth = 32,
.max_bpw = 32,
.unidir = false,
};
static struct amba_id pl022_ids[] = {
{
/*
* ARM PL022 variant, this has a 16bit wide
* and 8 locations deep TX/RX FIFO
*/
.id = 0x00041022,
.mask = 0x000fffff,
.data = &vendor_arm,
},
{
/*
* ST Micro derivative, this has 32bit wide
* and 32 locations deep TX/RX FIFO
*/
.id = 0x00108022,
.mask = 0xffffffff,
.data = &vendor_st,
},
{ 0, 0 },
};
static struct amba_driver pl022_driver = {
.drv = {
.name = "ssp-pl022",
},
.id_table = pl022_ids,
.probe = pl022_probe,
.remove = __exit_p(pl022_remove),
.suspend = pl022_suspend,
.resume = pl022_resume,
};
static int __init pl022_init(void)
{
return amba_driver_register(&pl022_driver);
}
module_init(pl022_init);
static void __exit pl022_exit(void)
{
amba_driver_unregister(&pl022_driver);
}
module_exit(pl022_exit);
MODULE_AUTHOR("Linus Walleij <linus.walleij@stericsson.com>");
MODULE_DESCRIPTION("PL022 SSP Controller Driver");
MODULE_LICENSE("GPL");
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