android_kernel_xiaomi_sm8350/drivers/spi/spi_s3c24xx_gpio.c
David Brownell fc3ba9525b SPI driver hotplug/coldplug fixes
Update various SPI drivers so they properly support

  - coldplug through "modprobe $(cat /sys/devices/.../modalias)"

  - hotplug through "modprobe $(MODALIAS)"

The basic rule for platform, SPI, and (new style) I2C drivers is just
to make sure that modprobing the driver name works.  In this case, all
the relevant drivers are platform drivers, and this patch either

  (a)	Changes the driver name, if no in-tree code would break;
	this is simpler and thus preferable in the long term.

  (b)	Adds MODULE_ALIAS directives, when in-tree platforms declare
	devices using the current driver name; less desirable.

Most systems will link SPI controller drivers statically, but
there's no point in being needlessly broken.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Cc: Jean Delvare <khali@linux-fr.org>
Acked-by: Andrei Konovalov <akonovalov@ru.mvista.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-08-31 01:42:22 -07:00

204 lines
5.0 KiB
C

/* linux/drivers/spi/spi_s3c24xx_gpio.c
*
* Copyright (c) 2006 Ben Dooks
* Copyright (c) 2006 Simtec Electronics
*
* S3C24XX GPIO based SPI driver
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
*/
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/delay.h>
#include <linux/spinlock.h>
#include <linux/workqueue.h>
#include <linux/platform_device.h>
#include <linux/spi/spi.h>
#include <linux/spi/spi_bitbang.h>
#include <asm/arch/regs-gpio.h>
#include <asm/arch/spi-gpio.h>
#include <asm/hardware.h>
struct s3c2410_spigpio {
struct spi_bitbang bitbang;
struct s3c2410_spigpio_info *info;
struct platform_device *dev;
};
static inline struct s3c2410_spigpio *spidev_to_sg(struct spi_device *spi)
{
return spi->controller_data;
}
static inline void setsck(struct spi_device *dev, int on)
{
struct s3c2410_spigpio *sg = spidev_to_sg(dev);
s3c2410_gpio_setpin(sg->info->pin_clk, on ? 1 : 0);
}
static inline void setmosi(struct spi_device *dev, int on)
{
struct s3c2410_spigpio *sg = spidev_to_sg(dev);
s3c2410_gpio_setpin(sg->info->pin_mosi, on ? 1 : 0);
}
static inline u32 getmiso(struct spi_device *dev)
{
struct s3c2410_spigpio *sg = spidev_to_sg(dev);
return s3c2410_gpio_getpin(sg->info->pin_miso) ? 1 : 0;
}
#define spidelay(x) ndelay(x)
#define EXPAND_BITBANG_TXRX
#include <linux/spi/spi_bitbang.h>
static u32 s3c2410_spigpio_txrx_mode0(struct spi_device *spi,
unsigned nsecs, u32 word, u8 bits)
{
return bitbang_txrx_be_cpha0(spi, nsecs, 0, word, bits);
}
static u32 s3c2410_spigpio_txrx_mode1(struct spi_device *spi,
unsigned nsecs, u32 word, u8 bits)
{
return bitbang_txrx_be_cpha1(spi, nsecs, 0, word, bits);
}
static u32 s3c2410_spigpio_txrx_mode2(struct spi_device *spi,
unsigned nsecs, u32 word, u8 bits)
{
return bitbang_txrx_be_cpha0(spi, nsecs, 1, word, bits);
}
static u32 s3c2410_spigpio_txrx_mode3(struct spi_device *spi,
unsigned nsecs, u32 word, u8 bits)
{
return bitbang_txrx_be_cpha1(spi, nsecs, 1, word, bits);
}
static void s3c2410_spigpio_chipselect(struct spi_device *dev, int value)
{
struct s3c2410_spigpio *sg = spidev_to_sg(dev);
if (sg->info && sg->info->chip_select)
(sg->info->chip_select)(sg->info, value);
}
static int s3c2410_spigpio_probe(struct platform_device *dev)
{
struct spi_master *master;
struct s3c2410_spigpio *sp;
int ret;
int i;
master = spi_alloc_master(&dev->dev, sizeof(struct s3c2410_spigpio));
if (master == NULL) {
dev_err(&dev->dev, "failed to allocate spi master\n");
ret = -ENOMEM;
goto err;
}
sp = spi_master_get_devdata(master);
platform_set_drvdata(dev, sp);
/* copy in the plkatform data */
sp->info = dev->dev.platform_data;
/* setup spi bitbang adaptor */
sp->bitbang.master = spi_master_get(master);
sp->bitbang.chipselect = s3c2410_spigpio_chipselect;
sp->bitbang.txrx_word[SPI_MODE_0] = s3c2410_spigpio_txrx_mode0;
sp->bitbang.txrx_word[SPI_MODE_1] = s3c2410_spigpio_txrx_mode1;
sp->bitbang.txrx_word[SPI_MODE_2] = s3c2410_spigpio_txrx_mode2;
sp->bitbang.txrx_word[SPI_MODE_3] = s3c2410_spigpio_txrx_mode3;
/* set state of spi pins */
s3c2410_gpio_setpin(sp->info->pin_clk, 0);
s3c2410_gpio_setpin(sp->info->pin_mosi, 0);
s3c2410_gpio_cfgpin(sp->info->pin_clk, S3C2410_GPIO_OUTPUT);
s3c2410_gpio_cfgpin(sp->info->pin_mosi, S3C2410_GPIO_OUTPUT);
s3c2410_gpio_cfgpin(sp->info->pin_miso, S3C2410_GPIO_INPUT);
ret = spi_bitbang_start(&sp->bitbang);
if (ret)
goto err_no_bitbang;
/* register the chips to go with the board */
for (i = 0; i < sp->info->board_size; i++) {
dev_info(&dev->dev, "registering %p: %s\n",
&sp->info->board_info[i],
sp->info->board_info[i].modalias);
sp->info->board_info[i].controller_data = sp;
spi_new_device(master, sp->info->board_info + i);
}
return 0;
err_no_bitbang:
spi_master_put(sp->bitbang.master);
err:
return ret;
}
static int s3c2410_spigpio_remove(struct platform_device *dev)
{
struct s3c2410_spigpio *sp = platform_get_drvdata(dev);
spi_bitbang_stop(&sp->bitbang);
spi_master_put(sp->bitbang.master);
return 0;
}
/* all gpio should be held over suspend/resume, so we should
* not need to deal with this
*/
#define s3c2410_spigpio_suspend NULL
#define s3c2410_spigpio_resume NULL
static struct platform_driver s3c2410_spigpio_drv = {
.probe = s3c2410_spigpio_probe,
.remove = s3c2410_spigpio_remove,
.suspend = s3c2410_spigpio_suspend,
.resume = s3c2410_spigpio_resume,
.driver = {
.name = "spi_s3c24xx_gpio",
.owner = THIS_MODULE,
},
};
static int __init s3c2410_spigpio_init(void)
{
return platform_driver_register(&s3c2410_spigpio_drv);
}
static void __exit s3c2410_spigpio_exit(void)
{
platform_driver_unregister(&s3c2410_spigpio_drv);
}
module_init(s3c2410_spigpio_init);
module_exit(s3c2410_spigpio_exit);
MODULE_DESCRIPTION("S3C24XX SPI Driver");
MODULE_AUTHOR("Ben Dooks, <ben@simtec.co.uk>");
MODULE_LICENSE("GPL");