linux-stable/drivers/spi/spi-s3c24xx.c

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// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (c) 2006 Ben Dooks
* Copyright 2006-2009 Simtec Electronics
* Ben Dooks <ben@simtec.co.uk>
*/
#include <linux/spinlock.h>
#include <linux/interrupt.h>
#include <linux/delay.h>
#include <linux/errno.h>
#include <linux/err.h>
#include <linux/clk.h>
#include <linux/platform_device.h>
#include <linux/gpio.h>
#include <linux/io.h>
include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo <tj@kernel.org> Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-24 08:04:11 +00:00
#include <linux/slab.h>
#include <linux/spi/spi.h>
#include <linux/spi/spi_bitbang.h>
#include <linux/spi/s3c24xx.h>
#include <linux/spi/s3c24xx-fiq.h>
#include <linux/module.h>
#include <asm/fiq.h>
#include "spi-s3c24xx-regs.h"
/**
* struct s3c24xx_spi_devstate - per device data
* @hz: Last frequency calculated for @sppre field.
* @mode: Last mode setting for the @spcon field.
* @spcon: Value to write to the SPCON register.
* @sppre: Value to write to the SPPRE register.
*/
struct s3c24xx_spi_devstate {
unsigned int hz;
unsigned int mode;
u8 spcon;
u8 sppre;
};
enum spi_fiq_mode {
FIQ_MODE_NONE = 0,
FIQ_MODE_TX = 1,
FIQ_MODE_RX = 2,
FIQ_MODE_TXRX = 3,
};
struct s3c24xx_spi {
/* bitbang has to be first */
struct spi_bitbang bitbang;
struct completion done;
void __iomem *regs;
int irq;
int len;
int count;
struct fiq_handler fiq_handler;
enum spi_fiq_mode fiq_mode;
unsigned char fiq_inuse;
unsigned char fiq_claimed;
void (*set_cs)(struct s3c2410_spi_info *spi,
int cs, int pol);
/* data buffers */
const unsigned char *tx;
unsigned char *rx;
struct clk *clk;
struct spi_master *master;
struct spi_device *curdev;
struct device *dev;
struct s3c2410_spi_info *pdata;
};
#define SPCON_DEFAULT (S3C2410_SPCON_MSTR | S3C2410_SPCON_SMOD_INT)
#define SPPIN_DEFAULT (S3C2410_SPPIN_KEEP)
static inline struct s3c24xx_spi *to_hw(struct spi_device *sdev)
{
return spi_master_get_devdata(sdev->master);
}
static void s3c24xx_spi_gpiocs(struct s3c2410_spi_info *spi, int cs, int pol)
{
gpio_set_value(spi->pin_cs, pol);
}
static void s3c24xx_spi_chipsel(struct spi_device *spi, int value)
{
struct s3c24xx_spi_devstate *cs = spi->controller_state;
struct s3c24xx_spi *hw = to_hw(spi);
unsigned int cspol = spi->mode & SPI_CS_HIGH ? 1 : 0;
/* change the chipselect state and the state of the spi engine clock */
switch (value) {
case BITBANG_CS_INACTIVE:
hw->set_cs(hw->pdata, spi->chip_select, cspol^1);
writeb(cs->spcon, hw->regs + S3C2410_SPCON);
break;
case BITBANG_CS_ACTIVE:
writeb(cs->spcon | S3C2410_SPCON_ENSCK,
hw->regs + S3C2410_SPCON);
hw->set_cs(hw->pdata, spi->chip_select, cspol);
break;
}
}
static int s3c24xx_spi_update_state(struct spi_device *spi,
struct spi_transfer *t)
{
struct s3c24xx_spi *hw = to_hw(spi);
struct s3c24xx_spi_devstate *cs = spi->controller_state;
unsigned int hz;
unsigned int div;
unsigned long clk;
hz = t ? t->speed_hz : spi->max_speed_hz;
if (!hz)
hz = spi->max_speed_hz;
if (spi->mode != cs->mode) {
u8 spcon = SPCON_DEFAULT | S3C2410_SPCON_ENSCK;
if (spi->mode & SPI_CPHA)
spcon |= S3C2410_SPCON_CPHA_FMTB;
if (spi->mode & SPI_CPOL)
spcon |= S3C2410_SPCON_CPOL_HIGH;
cs->mode = spi->mode;
cs->spcon = spcon;
}
if (cs->hz != hz) {
clk = clk_get_rate(hw->clk);
div = DIV_ROUND_UP(clk, hz * 2) - 1;
if (div > 255)
div = 255;
dev_dbg(&spi->dev, "pre-scaler=%d (wanted %d, got %ld)\n",
div, hz, clk / (2 * (div + 1)));
cs->hz = hz;
cs->sppre = div;
}
return 0;
}
static int s3c24xx_spi_setupxfer(struct spi_device *spi,
struct spi_transfer *t)
{
struct s3c24xx_spi_devstate *cs = spi->controller_state;
struct s3c24xx_spi *hw = to_hw(spi);
int ret;
ret = s3c24xx_spi_update_state(spi, t);
if (!ret)
writeb(cs->sppre, hw->regs + S3C2410_SPPRE);
return ret;
}
static int s3c24xx_spi_setup(struct spi_device *spi)
{
struct s3c24xx_spi_devstate *cs = spi->controller_state;
struct s3c24xx_spi *hw = to_hw(spi);
int ret;
/* allocate settings on the first call */
if (!cs) {
cs = devm_kzalloc(&spi->dev,
sizeof(struct s3c24xx_spi_devstate),
GFP_KERNEL);
if (!cs)
return -ENOMEM;
cs->spcon = SPCON_DEFAULT;
cs->hz = -1;
spi->controller_state = cs;
}
/* initialise the state from the device */
ret = s3c24xx_spi_update_state(spi, NULL);
if (ret)
return ret;
mutex_lock(&hw->bitbang.lock);
if (!hw->bitbang.busy) {
hw->bitbang.chipselect(spi, BITBANG_CS_INACTIVE);
/* need to ndelay for 0.5 clocktick ? */
}
mutex_unlock(&hw->bitbang.lock);
return 0;
}
static inline unsigned int hw_txbyte(struct s3c24xx_spi *hw, int count)
{
return hw->tx ? hw->tx[count] : 0;
}
#ifdef CONFIG_SPI_S3C24XX_FIQ
/* Support for FIQ based pseudo-DMA to improve the transfer speed.
*
* This code uses the assembly helper in spi_s3c24xx_spi.S which is
* used by the FIQ core to move data between main memory and the peripheral
* block. Since this is code running on the processor, there is no problem
* with cache coherency of the buffers, so we can use any buffer we like.
*/
/**
* struct spi_fiq_code - FIQ code and header
* @length: The length of the code fragment, excluding this header.
* @ack_offset: The offset from @data to the word to place the IRQ ACK bit at.
* @data: The code itself to install as a FIQ handler.
*/
struct spi_fiq_code {
u32 length;
u32 ack_offset;
u8 data[];
};
/**
* s3c24xx_spi_tryfiq - attempt to claim and setup FIQ for transfer
* @hw: The hardware state.
*
* Claim the FIQ handler (only one can be active at any one time) and
* then setup the correct transfer code for this transfer.
*
* This call updates all the necessary state information if successful,
* so the caller does not need to do anything more than start the transfer
* as normal, since the IRQ will have been re-routed to the FIQ handler.
*/
static void s3c24xx_spi_tryfiq(struct s3c24xx_spi *hw)
{
struct pt_regs regs;
enum spi_fiq_mode mode;
struct spi_fiq_code *code;
u32 *ack_ptr = NULL;
int ret;
if (!hw->fiq_claimed) {
/* try and claim fiq if we haven't got it, and if not
* then return and simply use another transfer method */
ret = claim_fiq(&hw->fiq_handler);
if (ret)
return;
}
if (hw->tx && !hw->rx)
mode = FIQ_MODE_TX;
else if (hw->rx && !hw->tx)
mode = FIQ_MODE_RX;
else
mode = FIQ_MODE_TXRX;
regs.uregs[fiq_rspi] = (long)hw->regs;
regs.uregs[fiq_rrx] = (long)hw->rx;
regs.uregs[fiq_rtx] = (long)hw->tx + 1;
regs.uregs[fiq_rcount] = hw->len - 1;
set_fiq_regs(&regs);
if (hw->fiq_mode != mode) {
hw->fiq_mode = mode;
switch (mode) {
case FIQ_MODE_TX:
code = &s3c24xx_spi_fiq_tx;
break;
case FIQ_MODE_RX:
code = &s3c24xx_spi_fiq_rx;
break;
case FIQ_MODE_TXRX:
code = &s3c24xx_spi_fiq_txrx;
break;
default:
code = NULL;
}
BUG_ON(!code);
ack_ptr = (u32 *)&code->data[code->ack_offset];
set_fiq_handler(&code->data, code->length);
}
s3c24xx_set_fiq(hw->irq, ack_ptr, true);
hw->fiq_mode = mode;
hw->fiq_inuse = 1;
}
/**
* s3c24xx_spi_fiqop - FIQ core code callback
* @pw: Data registered with the handler
* @release: Whether this is a release or a return.
*
* Called by the FIQ code when another module wants to use the FIQ, so
* return whether we are currently using this or not and then update our
* internal state.
*/
static int s3c24xx_spi_fiqop(void *pw, int release)
{
struct s3c24xx_spi *hw = pw;
int ret = 0;
if (release) {
if (hw->fiq_inuse)
ret = -EBUSY;
/* note, we do not need to unroute the FIQ, as the FIQ
* vector code de-routes it to signal the end of transfer */
hw->fiq_mode = FIQ_MODE_NONE;
hw->fiq_claimed = 0;
} else {
hw->fiq_claimed = 1;
}
return ret;
}
/**
* s3c24xx_spi_initfiq - setup the information for the FIQ core
* @hw: The hardware state.
*
* Setup the fiq_handler block to pass to the FIQ core.
*/
static inline void s3c24xx_spi_initfiq(struct s3c24xx_spi *hw)
{
hw->fiq_handler.dev_id = hw;
hw->fiq_handler.name = dev_name(hw->dev);
hw->fiq_handler.fiq_op = s3c24xx_spi_fiqop;
}
/**
* s3c24xx_spi_usefiq - return if we should be using FIQ.
* @hw: The hardware state.
*
* Return true if the platform data specifies whether this channel is
* allowed to use the FIQ.
*/
static inline bool s3c24xx_spi_usefiq(struct s3c24xx_spi *hw)
{
return hw->pdata->use_fiq;
}
/**
* s3c24xx_spi_usingfiq - return if channel is using FIQ
* @spi: The hardware state.
*
* Return whether the channel is currently using the FIQ (separate from
* whether the FIQ is claimed).
*/
static inline bool s3c24xx_spi_usingfiq(struct s3c24xx_spi *spi)
{
return spi->fiq_inuse;
}
#else
static inline void s3c24xx_spi_initfiq(struct s3c24xx_spi *s) { }
static inline void s3c24xx_spi_tryfiq(struct s3c24xx_spi *s) { }
static inline bool s3c24xx_spi_usefiq(struct s3c24xx_spi *s) { return false; }
static inline bool s3c24xx_spi_usingfiq(struct s3c24xx_spi *s) { return false; }
#endif /* CONFIG_SPI_S3C24XX_FIQ */
static int s3c24xx_spi_txrx(struct spi_device *spi, struct spi_transfer *t)
{
struct s3c24xx_spi *hw = to_hw(spi);
hw->tx = t->tx_buf;
hw->rx = t->rx_buf;
hw->len = t->len;
hw->count = 0;
init_completion(&hw->done);
hw->fiq_inuse = 0;
if (s3c24xx_spi_usefiq(hw) && t->len >= 3)
s3c24xx_spi_tryfiq(hw);
/* send the first byte */
writeb(hw_txbyte(hw, 0), hw->regs + S3C2410_SPTDAT);
wait_for_completion(&hw->done);
return hw->count;
}
IRQ: Maintain regs pointer globally rather than passing to IRQ handlers Maintain a per-CPU global "struct pt_regs *" variable which can be used instead of passing regs around manually through all ~1800 interrupt handlers in the Linux kernel. The regs pointer is used in few places, but it potentially costs both stack space and code to pass it around. On the FRV arch, removing the regs parameter from all the genirq function results in a 20% speed up of the IRQ exit path (ie: from leaving timer_interrupt() to leaving do_IRQ()). Where appropriate, an arch may override the generic storage facility and do something different with the variable. On FRV, for instance, the address is maintained in GR28 at all times inside the kernel as part of general exception handling. Having looked over the code, it appears that the parameter may be handed down through up to twenty or so layers of functions. Consider a USB character device attached to a USB hub, attached to a USB controller that posts its interrupts through a cascaded auxiliary interrupt controller. A character device driver may want to pass regs to the sysrq handler through the input layer which adds another few layers of parameter passing. I've build this code with allyesconfig for x86_64 and i386. I've runtested the main part of the code on FRV and i386, though I can't test most of the drivers. I've also done partial conversion for powerpc and MIPS - these at least compile with minimal configurations. This will affect all archs. Mostly the changes should be relatively easy. Take do_IRQ(), store the regs pointer at the beginning, saving the old one: struct pt_regs *old_regs = set_irq_regs(regs); And put the old one back at the end: set_irq_regs(old_regs); Don't pass regs through to generic_handle_irq() or __do_IRQ(). In timer_interrupt(), this sort of change will be necessary: - update_process_times(user_mode(regs)); - profile_tick(CPU_PROFILING, regs); + update_process_times(user_mode(get_irq_regs())); + profile_tick(CPU_PROFILING); I'd like to move update_process_times()'s use of get_irq_regs() into itself, except that i386, alone of the archs, uses something other than user_mode(). Some notes on the interrupt handling in the drivers: (*) input_dev() is now gone entirely. The regs pointer is no longer stored in the input_dev struct. (*) finish_unlinks() in drivers/usb/host/ohci-q.c needs checking. It does something different depending on whether it's been supplied with a regs pointer or not. (*) Various IRQ handler function pointers have been moved to type irq_handler_t. Signed-Off-By: David Howells <dhowells@redhat.com> (cherry picked from 1b16e7ac850969f38b375e511e3fa2f474a33867 commit)
2006-10-05 13:55:46 +00:00
static irqreturn_t s3c24xx_spi_irq(int irq, void *dev)
{
struct s3c24xx_spi *hw = dev;
unsigned int spsta = readb(hw->regs + S3C2410_SPSTA);
unsigned int count = hw->count;
if (spsta & S3C2410_SPSTA_DCOL) {
dev_dbg(hw->dev, "data-collision\n");
complete(&hw->done);
goto irq_done;
}
if (!(spsta & S3C2410_SPSTA_READY)) {
dev_dbg(hw->dev, "spi not ready for tx?\n");
complete(&hw->done);
goto irq_done;
}
if (!s3c24xx_spi_usingfiq(hw)) {
hw->count++;
if (hw->rx)
hw->rx[count] = readb(hw->regs + S3C2410_SPRDAT);
count++;
if (count < hw->len)
writeb(hw_txbyte(hw, count), hw->regs + S3C2410_SPTDAT);
else
complete(&hw->done);
} else {
hw->count = hw->len;
hw->fiq_inuse = 0;
if (hw->rx)
hw->rx[hw->len-1] = readb(hw->regs + S3C2410_SPRDAT);
complete(&hw->done);
}
irq_done:
return IRQ_HANDLED;
}
static void s3c24xx_spi_initialsetup(struct s3c24xx_spi *hw)
{
/* for the moment, permanently enable the clock */
clk_enable(hw->clk);
/* program defaults into the registers */
writeb(0xff, hw->regs + S3C2410_SPPRE);
writeb(SPPIN_DEFAULT, hw->regs + S3C2410_SPPIN);
writeb(SPCON_DEFAULT, hw->regs + S3C2410_SPCON);
if (hw->pdata) {
if (hw->set_cs == s3c24xx_spi_gpiocs)
gpio_direction_output(hw->pdata->pin_cs, 1);
if (hw->pdata->gpio_setup)
hw->pdata->gpio_setup(hw->pdata, 1);
}
}
static int s3c24xx_spi_probe(struct platform_device *pdev)
{
struct s3c2410_spi_info *pdata;
struct s3c24xx_spi *hw;
struct spi_master *master;
int err = 0;
master = spi_alloc_master(&pdev->dev, sizeof(struct s3c24xx_spi));
if (master == NULL) {
dev_err(&pdev->dev, "No memory for spi_master\n");
return -ENOMEM;
}
hw = spi_master_get_devdata(master);
hw->master = master;
hw->pdata = pdata = dev_get_platdata(&pdev->dev);
hw->dev = &pdev->dev;
if (pdata == NULL) {
dev_err(&pdev->dev, "No platform data supplied\n");
err = -ENOENT;
goto err_no_pdata;
}
platform_set_drvdata(pdev, hw);
init_completion(&hw->done);
/* initialise fiq handler */
s3c24xx_spi_initfiq(hw);
/* setup the master state. */
/* the spi->mode bits understood by this driver: */
master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH;
master->num_chipselect = hw->pdata->num_cs;
master->bus_num = pdata->bus_num;
master->bits_per_word_mask = SPI_BPW_MASK(8);
/* setup the state for the bitbang driver */
hw->bitbang.master = hw->master;
hw->bitbang.setup_transfer = s3c24xx_spi_setupxfer;
hw->bitbang.chipselect = s3c24xx_spi_chipsel;
hw->bitbang.txrx_bufs = s3c24xx_spi_txrx;
hw->master->setup = s3c24xx_spi_setup;
dev_dbg(hw->dev, "bitbang at %p\n", &hw->bitbang);
/* find and map our resources */
hw->regs = devm_platform_ioremap_resource(pdev, 0);
if (IS_ERR(hw->regs)) {
err = PTR_ERR(hw->regs);
goto err_no_pdata;
}
hw->irq = platform_get_irq(pdev, 0);
if (hw->irq < 0) {
err = -ENOENT;
goto err_no_pdata;
}
err = devm_request_irq(&pdev->dev, hw->irq, s3c24xx_spi_irq, 0,
pdev->name, hw);
if (err) {
dev_err(&pdev->dev, "Cannot claim IRQ\n");
goto err_no_pdata;
}
hw->clk = devm_clk_get(&pdev->dev, "spi");
if (IS_ERR(hw->clk)) {
dev_err(&pdev->dev, "No clock for device\n");
err = PTR_ERR(hw->clk);
goto err_no_pdata;
}
/* setup any gpio we can */
if (!pdata->set_cs) {
if (pdata->pin_cs < 0) {
dev_err(&pdev->dev, "No chipselect pin\n");
err = -EINVAL;
goto err_register;
}
err = devm_gpio_request(&pdev->dev, pdata->pin_cs,
dev_name(&pdev->dev));
if (err) {
dev_err(&pdev->dev, "Failed to get gpio for cs\n");
goto err_register;
}
hw->set_cs = s3c24xx_spi_gpiocs;
gpio_direction_output(pdata->pin_cs, 1);
} else
hw->set_cs = pdata->set_cs;
s3c24xx_spi_initialsetup(hw);
/* register our spi controller */
err = spi_bitbang_start(&hw->bitbang);
if (err) {
dev_err(&pdev->dev, "Failed to register SPI master\n");
goto err_register;
}
return 0;
err_register:
clk_disable(hw->clk);
err_no_pdata:
spi_master_put(hw->master);
return err;
}
static int s3c24xx_spi_remove(struct platform_device *dev)
{
struct s3c24xx_spi *hw = platform_get_drvdata(dev);
spi_bitbang_stop(&hw->bitbang);
clk_disable(hw->clk);
spi_master_put(hw->master);
return 0;
}
#ifdef CONFIG_PM
static int s3c24xx_spi_suspend(struct device *dev)
{
struct s3c24xx_spi *hw = dev_get_drvdata(dev);
int ret;
ret = spi_master_suspend(hw->master);
if (ret)
return ret;
if (hw->pdata && hw->pdata->gpio_setup)
hw->pdata->gpio_setup(hw->pdata, 0);
clk_disable(hw->clk);
return 0;
}
static int s3c24xx_spi_resume(struct device *dev)
{
struct s3c24xx_spi *hw = dev_get_drvdata(dev);
s3c24xx_spi_initialsetup(hw);
return spi_master_resume(hw->master);
}
static const struct dev_pm_ops s3c24xx_spi_pmops = {
.suspend = s3c24xx_spi_suspend,
.resume = s3c24xx_spi_resume,
};
#define S3C24XX_SPI_PMOPS &s3c24xx_spi_pmops
#else
#define S3C24XX_SPI_PMOPS NULL
#endif /* CONFIG_PM */
MODULE_ALIAS("platform:s3c2410-spi");
static struct platform_driver s3c24xx_spi_driver = {
.probe = s3c24xx_spi_probe,
.remove = s3c24xx_spi_remove,
.driver = {
.name = "s3c2410-spi",
.pm = S3C24XX_SPI_PMOPS,
},
};
module_platform_driver(s3c24xx_spi_driver);
MODULE_DESCRIPTION("S3C24XX SPI Driver");
MODULE_AUTHOR("Ben Dooks, <ben@simtec.co.uk>");
MODULE_LICENSE("GPL");