Gabor Juhos
16 years ago
parent
55f3b8ade2
commit
74321caaf8
@ -1,242 +0,0 @@ |
||||
/*
|
||||
* Bitbanging SPI bus driver using GPIO API |
||||
* |
||||
* Copyright (c) 2008 Piotr Skamruk |
||||
* Copyright (c) 2008 Michael Buesch |
||||
* |
||||
* based on spi_s3c2410_gpio.c |
||||
* Copyright (c) 2006 Ben Dooks |
||||
* Copyright (c) 2006 Simtec Electronics |
||||
* and on i2c-gpio.c |
||||
* Copyright (C) 2007 Atmel Corporation |
||||
* |
||||
* 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/module.h> |
||||
#include <linux/platform_device.h> |
||||
#include <linux/spi/spi.h> |
||||
#include <linux/spi/spi_bitbang.h> |
||||
#include "linux/spi/spi_gpio.h" //XXX |
||||
#include <asm/gpio.h> |
||||
|
||||
|
||||
struct spi_gpio { |
||||
struct spi_bitbang bitbang; |
||||
struct spi_gpio_platform_data *info; |
||||
struct platform_device *pdev; |
||||
struct spi_board_info bi; |
||||
}; |
||||
|
||||
|
||||
static inline struct spi_gpio *spidev_to_sg(struct spi_device *dev) |
||||
{ |
||||
return dev->controller_data; |
||||
} |
||||
|
||||
static inline void setsck(struct spi_device *dev, int val) |
||||
{ |
||||
struct spi_gpio *sp = spidev_to_sg(dev); |
||||
gpio_set_value(sp->info->pin_clk, val ? 1 : 0); |
||||
} |
||||
|
||||
static inline void setmosi(struct spi_device *dev, int val ) |
||||
{ |
||||
struct spi_gpio *sp = spidev_to_sg(dev); |
||||
gpio_set_value(sp->info->pin_mosi, val ? 1 : 0); |
||||
} |
||||
|
||||
static inline u32 getmiso(struct spi_device *dev) |
||||
{ |
||||
struct spi_gpio *sp = spidev_to_sg(dev); |
||||
return gpio_get_value(sp->info->pin_miso) ? 1 : 0; |
||||
} |
||||
|
||||
static inline void do_spidelay(struct spi_device *dev, unsigned nsecs) |
||||
{ |
||||
struct spi_gpio *sp = spidev_to_sg(dev); |
||||
|
||||
if (!sp->info->no_spi_delay) |
||||
ndelay(nsecs); |
||||
} |
||||
|
||||
#define spidelay(nsecs) do { \ |
||||
/* Steal the spi_device pointer from our caller. \
|
||||
* The bitbang-API should probably get fixed here... */ \
|
||||
do_spidelay(spi, nsecs); \
|
||||
} while (0) |
||||
|
||||
#define EXPAND_BITBANG_TXRX |
||||
#include <linux/spi/spi_bitbang.h> |
||||
|
||||
static u32 spi_gpio_txrx_mode0(struct spi_device *spi, |
||||
unsigned nsecs, u32 word, u8 bits) |
||||
{ |
||||
return bitbang_txrx_be_cpha0(spi, nsecs, 0, word, bits); |
||||
} |
||||
|
||||
static u32 spi_gpio_txrx_mode1(struct spi_device *spi, |
||||
unsigned nsecs, u32 word, u8 bits) |
||||
{ |
||||
return bitbang_txrx_be_cpha1(spi, nsecs, 0, word, bits); |
||||
} |
||||
|
||||
static u32 spi_gpio_txrx_mode2(struct spi_device *spi, |
||||
unsigned nsecs, u32 word, u8 bits) |
||||
{ |
||||
return bitbang_txrx_be_cpha0(spi, nsecs, 1, word, bits); |
||||
} |
||||
|
||||
static u32 spi_gpio_txrx_mode3(struct spi_device *spi, |
||||
unsigned nsecs, u32 word, u8 bits) |
||||
{ |
||||
return bitbang_txrx_be_cpha1(spi, nsecs, 1, word, bits); |
||||
} |
||||
|
||||
static void spi_gpio_chipselect(struct spi_device *dev, int on) |
||||
{ |
||||
struct spi_gpio *sp = spidev_to_sg(dev); |
||||
|
||||
if (sp->info->cs_activelow) |
||||
on = !on; |
||||
gpio_set_value(sp->info->pin_cs, on ? 1 : 0); |
||||
} |
||||
|
||||
static int spi_gpio_probe(struct platform_device *pdev) |
||||
{ |
||||
struct spi_master *master; |
||||
struct spi_gpio_platform_data *pdata; |
||||
struct spi_gpio *sp; |
||||
struct spi_device *spidev; |
||||
int err; |
||||
|
||||
pdata = pdev->dev.platform_data; |
||||
if (!pdata) |
||||
return -ENXIO; |
||||
|
||||
err = -ENOMEM; |
||||
master = spi_alloc_master(&pdev->dev, sizeof(struct spi_gpio)); |
||||
if (!master) |
||||
goto err_alloc_master; |
||||
|
||||
sp = spi_master_get_devdata(master); |
||||
platform_set_drvdata(pdev, sp); |
||||
sp->info = pdata; |
||||
|
||||
err = gpio_request(pdata->pin_clk, "spi_clock"); |
||||
if (err) |
||||
goto err_request_clk; |
||||
err = gpio_request(pdata->pin_mosi, "spi_mosi"); |
||||
if (err) |
||||
goto err_request_mosi; |
||||
err = gpio_request(pdata->pin_miso, "spi_miso"); |
||||
if (err) |
||||
goto err_request_miso; |
||||
err = gpio_request(pdata->pin_cs, "spi_cs"); |
||||
if (err) |
||||
goto err_request_cs; |
||||
|
||||
sp->bitbang.master = spi_master_get(master); |
||||
sp->bitbang.master->bus_num = -1; |
||||
sp->bitbang.master->num_chipselect = 1; |
||||
sp->bitbang.chipselect = spi_gpio_chipselect; |
||||
sp->bitbang.txrx_word[SPI_MODE_0] = spi_gpio_txrx_mode0; |
||||
sp->bitbang.txrx_word[SPI_MODE_1] = spi_gpio_txrx_mode1; |
||||
sp->bitbang.txrx_word[SPI_MODE_2] = spi_gpio_txrx_mode2; |
||||
sp->bitbang.txrx_word[SPI_MODE_3] = spi_gpio_txrx_mode3; |
||||
|
||||
gpio_direction_output(pdata->pin_clk, 0); |
||||
gpio_direction_output(pdata->pin_mosi, 0); |
||||
gpio_direction_output(pdata->pin_cs, |
||||
pdata->cs_activelow ? 1 : 0); |
||||
gpio_direction_input(pdata->pin_miso); |
||||
|
||||
err = spi_bitbang_start(&sp->bitbang); |
||||
if (err) |
||||
goto err_no_bitbang; |
||||
err = pdata->boardinfo_setup(&sp->bi, master, |
||||
pdata->boardinfo_setup_data); |
||||
if (err) |
||||
goto err_bi_setup; |
||||
sp->bi.controller_data = sp; |
||||
spidev = spi_new_device(master, &sp->bi); |
||||
if (!spidev) |
||||
goto err_new_dev; |
||||
|
||||
return 0; |
||||
|
||||
err_new_dev: |
||||
err_bi_setup: |
||||
spi_bitbang_stop(&sp->bitbang); |
||||
err_no_bitbang: |
||||
spi_master_put(sp->bitbang.master); |
||||
gpio_free(pdata->pin_cs); |
||||
err_request_cs: |
||||
gpio_free(pdata->pin_miso); |
||||
err_request_miso: |
||||
gpio_free(pdata->pin_mosi); |
||||
err_request_mosi: |
||||
gpio_free(pdata->pin_clk); |
||||
err_request_clk: |
||||
kfree(master); |
||||
|
||||
err_alloc_master: |
||||
return err; |
||||
} |
||||
|
||||
static int __devexit spi_gpio_remove(struct platform_device *pdev) |
||||
{ |
||||
struct spi_gpio *sp; |
||||
struct spi_gpio_platform_data *pdata; |
||||
|
||||
pdata = pdev->dev.platform_data; |
||||
sp = platform_get_drvdata(pdev); |
||||
|
||||
gpio_free(pdata->pin_clk); |
||||
gpio_free(pdata->pin_mosi); |
||||
gpio_free(pdata->pin_miso); |
||||
gpio_free(pdata->pin_cs); |
||||
spi_bitbang_stop(&sp->bitbang); |
||||
spi_master_put(sp->bitbang.master); |
||||
|
||||
return 0; |
||||
} |
||||
|
||||
static struct platform_driver spi_gpio_driver = { |
||||
.driver = { |
||||
.name = "spi-gpio", |
||||
.owner = THIS_MODULE, |
||||
}, |
||||
.probe = spi_gpio_probe, |
||||
.remove = __devexit_p(spi_gpio_remove), |
||||
}; |
||||
|
||||
static int __init spi_gpio_init(void) |
||||
{ |
||||
int err; |
||||
|
||||
err = platform_driver_register(&spi_gpio_driver); |
||||
if (err) |
||||
printk(KERN_ERR "spi-gpio: register failed: %d\n", err); |
||||
|
||||
return err; |
||||
} |
||||
module_init(spi_gpio_init); |
||||
|
||||
static void __exit spi_gpio_exit(void) |
||||
{ |
||||
platform_driver_unregister(&spi_gpio_driver); |
||||
} |
||||
module_exit(spi_gpio_exit); |
||||
|
||||
MODULE_AUTHOR("Piot Skamruk <piotr.skamruk at gmail.com>"); |
||||
MODULE_AUTHOR("Michael Buesch"); |
||||
MODULE_DESCRIPTION("Platform independent GPIO bitbangling SPI driver"); |
||||
MODULE_LICENSE("GPL v2"); |
||||
@ -1,53 +0,0 @@ |
||||
/*
|
||||
* spi_gpio interface to platform code |
||||
* |
||||
* Copyright (c) 2008 Piotr Skamruk |
||||
* |
||||
* 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. |
||||
*/ |
||||
#ifndef _LINUX_SPI_SPI_GPIO |
||||
#define _LINUX_SPI_SPI_GPIO |
||||
|
||||
#include <linux/types.h> |
||||
#include <linux/spi/spi.h> |
||||
|
||||
|
||||
/** struct spi_gpio_platform_data - Data definitions for a SPI-GPIO device.
|
||||
* This structure holds information about a GPIO-based SPI device. |
||||
* |
||||
* @pin_clk: The GPIO pin number of the CLOCK pin. |
||||
* |
||||
* @pin_miso: The GPIO pin number of the MISO pin. |
||||
* |
||||
* @pin_mosi: The GPIO pin number of the MOSI pin. |
||||
* |
||||
* @pin_cs: The GPIO pin number of the CHIPSELECT pin. |
||||
* |
||||
* @cs_activelow: If true, the chip is selected when the CS line is low. |
||||
* |
||||
* @no_spi_delay: If true, no delay is done in the lowlevel bitbanging. |
||||
* Note that doing no delay is not standards compliant, |
||||
* but it might be needed to speed up transfers on some |
||||
* slow embedded machines. |
||||
* |
||||
* @boardinfo_setup: This callback is called after the |
||||
* SPI master device was registered, but before the |
||||
* device is registered. |
||||
* @boardinfo_setup_data: Data argument passed to boardinfo_setup(). |
||||
*/ |
||||
struct spi_gpio_platform_data { |
||||
unsigned int pin_clk; |
||||
unsigned int pin_miso; |
||||
unsigned int pin_mosi; |
||||
unsigned int pin_cs; |
||||
bool cs_activelow; |
||||
bool no_spi_delay; |
||||
int (*boardinfo_setup)(struct spi_board_info *bi, |
||||
struct spi_master *master, |
||||
void *data); |
||||
void *boardinfo_setup_data; |
||||
}; |
||||
|
||||
#endif /* _LINUX_SPI_SPI_GPIO */ |
||||
@ -0,0 +1,837 @@ |
||||
--- /dev/null
|
||||
+++ b/drivers/mmc/host/gpiommc.c
|
||||
@@ -0,0 +1,608 @@
|
||||
+/*
|
||||
+ * Driver an MMC/SD card on a bitbanging GPIO SPI bus.
|
||||
+ * This module hooks up the mmc_spi and spi_gpio modules and also
|
||||
+ * provides a configfs interface.
|
||||
+ *
|
||||
+ * Copyright 2008 Michael Buesch <mb@bu3sch.de>
|
||||
+ *
|
||||
+ * Licensed under the GNU/GPL. See COPYING for details.
|
||||
+ */
|
||||
+
|
||||
+#include <linux/mmc/gpiommc.h>
|
||||
+#include <linux/platform_device.h>
|
||||
+#include <linux/list.h>
|
||||
+#include <linux/mutex.h>
|
||||
+#include <linux/spi/spi_gpio.h>
|
||||
+#include <linux/configfs.h>
|
||||
+#include <linux/gpio.h>
|
||||
+#include <asm/atomic.h>
|
||||
+
|
||||
+
|
||||
+#define PFX "gpio-mmc: "
|
||||
+
|
||||
+
|
||||
+struct gpiommc_device {
|
||||
+ struct platform_device *pdev;
|
||||
+ struct platform_device *spi_pdev;
|
||||
+ struct spi_board_info boardinfo;
|
||||
+};
|
||||
+
|
||||
+
|
||||
+MODULE_DESCRIPTION("GPIO based MMC driver");
|
||||
+MODULE_AUTHOR("Michael Buesch");
|
||||
+MODULE_LICENSE("GPL");
|
||||
+
|
||||
+
|
||||
+static int gpiommc_boardinfo_setup(struct spi_board_info *bi,
|
||||
+ struct spi_master *master,
|
||||
+ void *data)
|
||||
+{
|
||||
+ struct gpiommc_device *d = data;
|
||||
+ struct gpiommc_platform_data *pdata = d->pdev->dev.platform_data;
|
||||
+
|
||||
+ /* Bind the SPI master to the MMC-SPI host driver. */
|
||||
+ strlcpy(bi->modalias, "mmc_spi", sizeof(bi->modalias));
|
||||
+
|
||||
+ bi->max_speed_hz = pdata->max_bus_speed;
|
||||
+ bi->bus_num = master->bus_num;
|
||||
+ bi->mode = pdata->mode;
|
||||
+
|
||||
+ return 0;
|
||||
+}
|
||||
+
|
||||
+static int gpiommc_probe(struct platform_device *pdev)
|
||||
+{
|
||||
+ struct gpiommc_platform_data *mmc_pdata = pdev->dev.platform_data;
|
||||
+ struct spi_gpio_platform_data spi_pdata;
|
||||
+ struct gpiommc_device *d;
|
||||
+ int err;
|
||||
+
|
||||
+ err = -ENXIO;
|
||||
+ if (!mmc_pdata)
|
||||
+ goto error;
|
||||
+
|
||||
+#ifdef CONFIG_MMC_SPI_MODULE
|
||||
+ err = request_module("mmc_spi");
|
||||
+ if (err) {
|
||||
+ printk(KERN_WARNING PFX
|
||||
+ "Failed to request mmc_spi module.\n");
|
||||
+ }
|
||||
+#endif /* CONFIG_MMC_SPI_MODULE */
|
||||
+
|
||||
+ /* Allocate the GPIO-MMC device */
|
||||
+ err = -ENOMEM;
|
||||
+ d = kzalloc(sizeof(*d), GFP_KERNEL);
|
||||
+ if (!d)
|
||||
+ goto error;
|
||||
+ d->pdev = pdev;
|
||||
+
|
||||
+ /* Create the SPI-GPIO device */
|
||||
+ d->spi_pdev = platform_device_alloc(SPI_GPIO_PLATDEV_NAME,
|
||||
+ spi_gpio_next_id());
|
||||
+ if (!d->spi_pdev)
|
||||
+ goto err_free_d;
|
||||
+
|
||||
+ memset(&spi_pdata, 0, sizeof(spi_pdata));
|
||||
+ spi_pdata.pin_clk = mmc_pdata->pins.gpio_clk;
|
||||
+ spi_pdata.pin_miso = mmc_pdata->pins.gpio_do;
|
||||
+ spi_pdata.pin_mosi = mmc_pdata->pins.gpio_di;
|
||||
+ spi_pdata.pin_cs = mmc_pdata->pins.gpio_cs;
|
||||
+ spi_pdata.cs_activelow = mmc_pdata->pins.cs_activelow;
|
||||
+ spi_pdata.no_spi_delay = mmc_pdata->no_spi_delay;
|
||||
+ spi_pdata.boardinfo_setup = gpiommc_boardinfo_setup;
|
||||
+ spi_pdata.boardinfo_setup_data = d;
|
||||
+
|
||||
+ err = platform_device_add_data(d->spi_pdev, &spi_pdata,
|
||||
+ sizeof(spi_pdata));
|
||||
+ if (err)
|
||||
+ goto err_free_pdev;
|
||||
+ err = platform_device_add(d->spi_pdev);
|
||||
+ if (err)
|
||||
+ goto err_free_pdata;
|
||||
+ platform_set_drvdata(pdev, d);
|
||||
+
|
||||
+ printk(KERN_INFO PFX "MMC-Card \"%s\" "
|
||||
+ "attached to GPIO pins di=%u, do=%u, clk=%u, cs=%u\n",
|
||||
+ mmc_pdata->name, mmc_pdata->pins.gpio_di,
|
||||
+ mmc_pdata->pins.gpio_do,
|
||||
+ mmc_pdata->pins.gpio_clk,
|
||||
+ mmc_pdata->pins.gpio_cs);
|
||||
+
|
||||
+ return 0;
|
||||
+
|
||||
+err_free_pdata:
|
||||
+ kfree(d->spi_pdev->dev.platform_data);
|
||||
+ d->spi_pdev->dev.platform_data = NULL;
|
||||
+err_free_pdev:
|
||||
+ platform_device_put(d->spi_pdev);
|
||||
+err_free_d:
|
||||
+ kfree(d);
|
||||
+error:
|
||||
+ return err;
|
||||
+}
|
||||
+
|
||||
+static int gpiommc_remove(struct platform_device *pdev)
|
||||
+{
|
||||
+ struct gpiommc_device *d = platform_get_drvdata(pdev);
|
||||
+ struct gpiommc_platform_data *pdata = d->pdev->dev.platform_data;
|
||||
+
|
||||
+ platform_device_unregister(d->spi_pdev);
|
||||
+ printk(KERN_INFO PFX "GPIO based MMC-Card \"%s\" removed\n",
|
||||
+ pdata->name);
|
||||
+ platform_device_put(d->spi_pdev);
|
||||
+
|
||||
+ return 0;
|
||||
+}
|
||||
+
|
||||
+#ifdef CONFIG_GPIOMMC_CONFIGFS
|
||||
+
|
||||
+/* A device that was created through configfs */
|
||||
+struct gpiommc_configfs_device {
|
||||
+ struct config_item item;
|
||||
+ /* The platform device, after registration. */
|
||||
+ struct platform_device *pdev;
|
||||
+ /* The configuration */
|
||||
+ struct gpiommc_platform_data pdata;
|
||||
+};
|
||||
+
|
||||
+#define GPIO_INVALID -1
|
||||
+
|
||||
+static inline bool gpiommc_is_registered(struct gpiommc_configfs_device *dev)
|
||||
+{
|
||||
+ return (dev->pdev != NULL);
|
||||
+}
|
||||
+
|
||||
+static inline struct gpiommc_configfs_device *ci_to_gpiommc(struct config_item *item)
|
||||
+{
|
||||
+ return item ? container_of(item, struct gpiommc_configfs_device, item) : NULL;
|
||||
+}
|
||||
+
|
||||
+static struct configfs_attribute gpiommc_attr_DI = {
|
||||
+ .ca_owner = THIS_MODULE,
|
||||
+ .ca_name = "gpio_data_in",
|
||||
+ .ca_mode = S_IRUGO | S_IWUSR,
|
||||
+};
|
||||
+
|
||||
+static struct configfs_attribute gpiommc_attr_DO = {
|
||||
+ .ca_owner = THIS_MODULE,
|
||||
+ .ca_name = "gpio_data_out",
|
||||
+ .ca_mode = S_IRUGO | S_IWUSR,
|
||||
+};
|
||||
+
|
||||
+static struct configfs_attribute gpiommc_attr_CLK = {
|
||||
+ .ca_owner = THIS_MODULE,
|
||||
+ .ca_name = "gpio_clock",
|
||||
+ .ca_mode = S_IRUGO | S_IWUSR,
|
||||
+};
|
||||
+
|
||||
+static struct configfs_attribute gpiommc_attr_CS = {
|
||||
+ .ca_owner = THIS_MODULE,
|
||||
+ .ca_name = "gpio_chipselect",
|
||||
+ .ca_mode = S_IRUGO | S_IWUSR,
|
||||
+};
|
||||
+
|
||||
+static struct configfs_attribute gpiommc_attr_CS_activelow = {
|
||||
+ .ca_owner = THIS_MODULE,
|
||||
+ .ca_name = "gpio_chipselect_activelow",
|
||||
+ .ca_mode = S_IRUGO | S_IWUSR,
|
||||
+};
|
||||
+
|
||||
+static struct configfs_attribute gpiommc_attr_spimode = {
|
||||
+ .ca_owner = THIS_MODULE,
|
||||
+ .ca_name = "spi_mode",
|
||||
+ .ca_mode = S_IRUGO | S_IWUSR,
|
||||
+};
|
||||
+
|
||||
+static struct configfs_attribute gpiommc_attr_spidelay = {
|
||||
+ .ca_owner = THIS_MODULE,
|
||||
+ .ca_name = "spi_delay",
|
||||
+ .ca_mode = S_IRUGO | S_IWUSR,
|
||||
+};
|
||||
+
|
||||
+static struct configfs_attribute gpiommc_attr_max_bus_speed = {
|
||||
+ .ca_owner = THIS_MODULE,
|
||||
+ .ca_name = "max_bus_speed",
|
||||
+ .ca_mode = S_IRUGO | S_IWUSR,
|
||||
+};
|
||||
+
|
||||
+static struct configfs_attribute gpiommc_attr_register = {
|
||||
+ .ca_owner = THIS_MODULE,
|
||||
+ .ca_name = "register",
|
||||
+ .ca_mode = S_IRUGO | S_IWUSR,
|
||||
+};
|
||||
+
|
||||
+static struct configfs_attribute *gpiommc_config_attrs[] = {
|
||||
+ &gpiommc_attr_DI,
|
||||
+ &gpiommc_attr_DO,
|
||||
+ &gpiommc_attr_CLK,
|
||||
+ &gpiommc_attr_CS,
|
||||
+ &gpiommc_attr_CS_activelow,
|
||||
+ &gpiommc_attr_spimode,
|
||||
+ &gpiommc_attr_spidelay,
|
||||
+ &gpiommc_attr_max_bus_speed,
|
||||
+ &gpiommc_attr_register,
|
||||
+ NULL,
|
||||
+};
|
||||
+
|
||||
+static ssize_t gpiommc_config_attr_show(struct config_item *item,
|
||||
+ struct configfs_attribute *attr,
|
||||
+ char *page)
|
||||
+{
|
||||
+ struct gpiommc_configfs_device *dev = ci_to_gpiommc(item);
|
||||
+ ssize_t count = 0;
|
||||
+ unsigned int gpio;
|
||||
+ int err = 0;
|
||||
+
|
||||
+ if (attr == &gpiommc_attr_DI) {
|
||||
+ gpio = dev->pdata.pins.gpio_di;
|
||||
+ if (gpio == GPIO_INVALID)
|
||||
+ count = snprintf(page, PAGE_SIZE, "not configured\n");
|
||||
+ else
|
||||
+ count = snprintf(page, PAGE_SIZE, "%u\n", gpio);
|
||||
+ goto out;
|
||||
+ }
|
||||
+ if (attr == &gpiommc_attr_DO) {
|
||||
+ gpio = dev->pdata.pins.gpio_do;
|
||||
+ if (gpio == GPIO_INVALID)
|
||||
+ count = snprintf(page, PAGE_SIZE, "not configured\n");
|
||||
+ else
|
||||
+ count = snprintf(page, PAGE_SIZE, "%u\n", gpio);
|
||||
+ goto out;
|
||||
+ }
|
||||
+ if (attr == &gpiommc_attr_CLK) {
|
||||
+ gpio = dev->pdata.pins.gpio_clk;
|
||||
+ if (gpio == GPIO_INVALID)
|
||||
+ count = snprintf(page, PAGE_SIZE, "not configured\n");
|
||||
+ else
|
||||
+ count = snprintf(page, PAGE_SIZE, "%u\n", gpio);
|
||||
+ goto out;
|
||||
+ }
|
||||
+ if (attr == &gpiommc_attr_CS) {
|
||||
+ gpio = dev->pdata.pins.gpio_cs;
|
||||
+ if (gpio == GPIO_INVALID)
|
||||
+ count = snprintf(page, PAGE_SIZE, "not configured\n");
|
||||
+ else
|
||||
+ count = snprintf(page, PAGE_SIZE, "%u\n", gpio);
|
||||
+ goto out;
|
||||
+ }
|
||||
+ if (attr == &gpiommc_attr_CS_activelow) {
|
||||
+ count = snprintf(page, PAGE_SIZE, "%u\n",
|
||||
+ dev->pdata.pins.cs_activelow);
|
||||
+ goto out;
|
||||
+ }
|
||||
+ if (attr == &gpiommc_attr_spimode) {
|
||||
+ count = snprintf(page, PAGE_SIZE, "%u\n",
|
||||
+ dev->pdata.mode);
|
||||
+ goto out;
|
||||
+ }
|
||||
+ if (attr == &gpiommc_attr_spidelay) {
|
||||
+ count = snprintf(page, PAGE_SIZE, "%u\n",
|
||||
+ !dev->pdata.no_spi_delay);
|
||||
+ goto out;
|
||||
+ }
|
||||
+ if (attr == &gpiommc_attr_max_bus_speed) {
|
||||
+ count = snprintf(page, PAGE_SIZE, "%u\n",
|
||||
+ dev->pdata.max_bus_speed);
|
||||
+ goto out;
|
||||
+ }
|
||||
+ if (attr == &gpiommc_attr_register) {
|
||||
+ count = snprintf(page, PAGE_SIZE, "%u\n",
|
||||
+ gpiommc_is_registered(dev));
|
||||
+ goto out;
|
||||
+ }
|
||||
+ WARN_ON(1);
|
||||
+ err = -ENOSYS;
|
||||
+out:
|
||||
+ return err ? err : count;
|
||||
+}
|
||||
+
|
||||
+static int gpiommc_do_register(struct gpiommc_configfs_device *dev,
|
||||
+ const char *name)
|
||||
+{
|
||||
+ int err;
|
||||
+
|
||||
+ if (gpiommc_is_registered(dev))
|
||||
+ return 0;
|
||||
+
|
||||
+ if (!gpio_is_valid(dev->pdata.pins.gpio_di) ||
|
||||
+ !gpio_is_valid(dev->pdata.pins.gpio_do) ||
|
||||
+ !gpio_is_valid(dev->pdata.pins.gpio_clk) ||
|
||||
+ !gpio_is_valid(dev->pdata.pins.gpio_cs)) {
|
||||
+ printk(KERN_ERR PFX
|
||||
+ "configfs: Invalid GPIO pin number(s)\n");
|
||||
+ return -EINVAL;
|
||||
+ }
|
||||
+
|
||||
+ strlcpy(dev->pdata.name, name,
|
||||
+ sizeof(dev->pdata.name));
|
||||
+
|
||||
+ dev->pdev = platform_device_alloc(GPIOMMC_PLATDEV_NAME,
|
||||
+ gpiommc_next_id());
|
||||
+ if (!dev->pdev)
|
||||
+ return -ENOMEM;
|
||||
+ err = platform_device_add_data(dev->pdev, &dev->pdata,
|
||||
+ sizeof(dev->pdata));
|
||||
+ if (err) {
|
||||
+ platform_device_put(dev->pdev);
|
||||
+ return err;
|
||||
+ }
|
||||
+ err = platform_device_add(dev->pdev);
|
||||
+ if (err) {
|
||||
+ platform_device_put(dev->pdev);
|
||||
+ return err;
|
||||
+ }
|
||||
+
|
||||
+ return 0;
|
||||
+}
|
||||
+
|
||||
+static void gpiommc_do_unregister(struct gpiommc_configfs_device *dev)
|
||||
+{
|
||||
+ if (!gpiommc_is_registered(dev))
|
||||
+ return;
|
||||
+
|
||||
+ platform_device_unregister(dev->pdev);
|
||||
+ dev->pdev = NULL;
|
||||
+}
|
||||
+
|
||||
+static ssize_t gpiommc_config_attr_store(struct config_item *item,
|
||||
+ struct configfs_attribute *attr,
|
||||
+ const char *page, size_t count)
|
||||
+{
|
||||
+ struct gpiommc_configfs_device *dev = ci_to_gpiommc(item);
|
||||
+ int err = -EINVAL;
|
||||
+ unsigned long data;
|
||||
+
|
||||
+ if (attr == &gpiommc_attr_register) {
|
||||
+ err = strict_strtoul(page, 10, &data);
|
||||
+ if (err)
|
||||
+ goto out;
|
||||
+ err = -EINVAL;
|
||||
+ if (data == 1)
|
||||
+ err = gpiommc_do_register(dev, item->ci_name);
|
||||
+ if (data == 0) {
|
||||
+ gpiommc_do_unregister(dev);
|
||||
+ err = 0;
|
||||
+ }
|
||||
+ goto out;
|
||||
+ }
|
||||
+
|
||||
+ if (gpiommc_is_registered(dev)) {
|
||||
+ /* The rest of the config parameters can only be set
|
||||
+ * as long as the device is not registered, yet. */
|
||||
+ err = -EBUSY;
|
||||
+ goto out;
|
||||
+ }
|
||||
+
|
||||
+ if (attr == &gpiommc_attr_DI) {
|
||||
+ err = strict_strtoul(page, 10, &data);
|
||||
+ if (err)
|
||||
+ goto out;
|
||||
+ err = -EINVAL;
|
||||
+ if (!gpio_is_valid(data))
|
||||
+ goto out;
|
||||
+ dev->pdata.pins.gpio_di = data;
|
||||
+ err = 0;
|
||||
+ goto out;
|
||||
+ }
|
||||
+ if (attr == &gpiommc_attr_DO) {
|
||||
+ err = strict_strtoul(page, 10, &data);
|
||||
+ if (err)
|
||||
+ goto out;
|
||||
+ err = -EINVAL;
|
||||
+ if (!gpio_is_valid(data))
|
||||
+ goto out;
|
||||
+ dev->pdata.pins.gpio_do = data;
|
||||
+ err = 0;
|
||||
+ goto out;
|
||||
+ }
|
||||
+ if (attr == &gpiommc_attr_CLK) {
|
||||
+ err = strict_strtoul(page, 10, &data);
|
||||
+ if (err)
|
||||
+ goto out;
|
||||
+ err = -EINVAL;
|
||||
+ if (!gpio_is_valid(data))
|
||||
+ goto out;
|
||||
+ dev->pdata.pins.gpio_clk = data;
|
||||
+ err = 0;
|
||||
+ goto out;
|
||||
+ }
|
||||
+ if (attr == &gpiommc_attr_CS) {
|
||||
+ err = strict_strtoul(page, 10, &data);
|
||||
+ if (err)
|
||||
+ goto out;
|
||||
+ err = -EINVAL;
|
||||
+ if (!gpio_is_valid(data))
|
||||
+ goto out;
|
||||
+ dev->pdata.pins.gpio_cs = data;
|
||||
+ err = 0;
|
||||
+ goto out;
|
||||
+ }
|
||||
+ if (attr == &gpiommc_attr_CS_activelow) {
|
||||
+ err = strict_strtoul(page, 10, &data);
|
||||
+ if (err)
|
||||
+ goto out;
|
||||
+ err = -EINVAL;
|
||||
+ if (data != 0 && data != 1)
|
||||
+ goto out;
|
||||
+ dev->pdata.pins.cs_activelow = data;
|
||||
+ err = 0;
|
||||
+ goto out;
|
||||
+ }
|
||||
+ if (attr == &gpiommc_attr_spimode) {
|
||||
+ err = strict_strtoul(page, 10, &data);
|
||||
+ if (err)
|
||||
+ goto out;
|
||||
+ err = -EINVAL;
|
||||
+ switch (data) {
|
||||
+ case 0:
|
||||
+ dev->pdata.mode = SPI_MODE_0;
|
||||
+ break;
|
||||
+ case 1:
|
||||
+ dev->pdata.mode = SPI_MODE_1;
|
||||
+ break;
|
||||
+ case 2:
|
||||
+ dev->pdata.mode = SPI_MODE_2;
|
||||
+ break;
|
||||
+ case 3:
|
||||
+ dev->pdata.mode = SPI_MODE_3;
|
||||
+ break;
|
||||
+ default:
|
||||
+ goto out;
|
||||
+ }
|
||||
+ err = 0;
|
||||
+ goto out;
|
||||
+ }
|
||||
+ if (attr == &gpiommc_attr_spidelay) {
|
||||
+ err = strict_strtoul(page, 10, &data);
|
||||
+ if (err)
|
||||
+ goto out;
|
||||
+ err = -EINVAL;
|
||||
+ if (data != 0 && data != 1)
|
||||
+ goto out;
|
||||
+ dev->pdata.no_spi_delay = !data;
|
||||
+ err = 0;
|
||||
+ goto out;
|
||||
+ }
|
||||
+ if (attr == &gpiommc_attr_max_bus_speed) {
|
||||
+ err = strict_strtoul(page, 10, &data);
|
||||
+ if (err)
|
||||
+ goto out;
|
||||
+ err = -EINVAL;
|
||||
+ if (data > UINT_MAX)
|
||||
+ goto out;
|
||||
+ dev->pdata.max_bus_speed = data;
|
||||
+ err = 0;
|
||||
+ goto out;
|
||||
+ }
|
||||
+ WARN_ON(1);
|
||||
+ err = -ENOSYS;
|
||||
+out:
|
||||
+ return err ? err : count;
|
||||
+}
|
||||
+
|
||||
+static void gpiommc_config_item_release(struct config_item *item)
|
||||
+{
|
||||
+ struct gpiommc_configfs_device *dev = ci_to_gpiommc(item);
|
||||
+
|
||||
+ kfree(dev);
|
||||
+}
|
||||
+
|
||||
+static struct configfs_item_operations gpiommc_config_item_ops = {
|
||||
+ .release = gpiommc_config_item_release,
|
||||
+ .show_attribute = gpiommc_config_attr_show,
|
||||
+ .store_attribute = gpiommc_config_attr_store,
|
||||
+};
|
||||
+
|
||||
+static struct config_item_type gpiommc_dev_ci_type = {
|
||||
+ .ct_item_ops = &gpiommc_config_item_ops,
|
||||
+ .ct_attrs = gpiommc_config_attrs,
|
||||
+ .ct_owner = THIS_MODULE,
|
||||
+};
|
||||
+
|
||||
+static struct config_item *gpiommc_make_item(struct config_group *group,
|
||||
+ const char *name)
|
||||
+{
|
||||
+ struct gpiommc_configfs_device *dev;
|
||||
+
|
||||
+ if (strlen(name) > GPIOMMC_MAX_NAMELEN) {
|
||||
+ printk(KERN_ERR PFX "configfs: device name too long\n");
|
||||
+ return NULL;
|
||||
+ }
|
||||
+
|
||||
+ dev = kzalloc(sizeof(*dev), GFP_KERNEL);
|
||||
+ if (!dev)
|
||||
+ return NULL;
|
||||
+
|
||||
+ config_item_init_type_name(&dev->item, name,
|
||||
+ &gpiommc_dev_ci_type);
|
||||
+
|
||||
+ /* Assign default configuration */
|
||||
+ dev->pdata.pins.gpio_di = GPIO_INVALID;
|
||||
+ dev->pdata.pins.gpio_do = GPIO_INVALID;
|
||||
+ dev->pdata.pins.gpio_clk = GPIO_INVALID;
|
||||
+ dev->pdata.pins.gpio_cs = GPIO_INVALID;
|
||||
+ dev->pdata.pins.cs_activelow = 1;
|
||||
+ dev->pdata.mode = SPI_MODE_0;
|
||||
+ dev->pdata.no_spi_delay = 0;
|
||||
+ dev->pdata.max_bus_speed = 5000000; /* 5 MHz */
|
||||
+
|
||||
+ return &(dev->item);
|
||||
+}
|
||||
+
|
||||
+static void gpiommc_drop_item(struct config_group *group,
|
||||
+ struct config_item *item)
|
||||
+{
|
||||
+ struct gpiommc_configfs_device *dev = ci_to_gpiommc(item);
|
||||
+
|
||||
+ gpiommc_do_unregister(dev);
|
||||
+ kfree(dev);
|
||||
+}
|
||||
+
|
||||
+static struct configfs_group_operations gpiommc_ct_group_ops = {
|
||||
+ .make_item = gpiommc_make_item,
|
||||
+ .drop_item = gpiommc_drop_item,
|
||||
+};
|
||||
+
|
||||
+static struct config_item_type gpiommc_ci_type = {
|
||||
+ .ct_group_ops = &gpiommc_ct_group_ops,
|
||||
+ .ct_owner = THIS_MODULE,
|
||||
+};
|
||||
+
|
||||
+static struct configfs_subsystem gpiommc_subsys = {
|
||||
+ .su_group = {
|
||||
+ .cg_item = {
|
||||
+ .ci_namebuf = GPIOMMC_PLATDEV_NAME,
|
||||
+ .ci_type = &gpiommc_ci_type,
|
||||
+ },
|
||||
+ },
|
||||
+ .su_mutex = __MUTEX_INITIALIZER(gpiommc_subsys.su_mutex),
|
||||
+};
|
||||
+
|
||||
+#endif /* CONFIG_GPIOMMC_CONFIGFS */
|
||||
+
|
||||
+static struct platform_driver gpiommc_plat_driver = {
|
||||
+ .probe = gpiommc_probe,
|
||||
+ .remove = gpiommc_remove,
|
||||
+ .driver = {
|
||||
+ .name = GPIOMMC_PLATDEV_NAME,
|
||||
+ .owner = THIS_MODULE,
|
||||
+ },
|
||||
+};
|
||||
+
|
||||
+int gpiommc_next_id(void)
|
||||
+{
|
||||
+ static atomic_t counter = ATOMIC_INIT(-1);
|
||||
+
|
||||
+ return atomic_inc_return(&counter);
|
||||
+}
|
||||
+EXPORT_SYMBOL(gpiommc_next_id);
|
||||
+
|
||||
+static int __init gpiommc_modinit(void)
|
||||
+{
|
||||
+ int err;
|
||||
+
|
||||
+ err = platform_driver_register(&gpiommc_plat_driver);
|
||||
+ if (err)
|
||||
+ return err;
|
||||
+
|
||||
+#ifdef CONFIG_GPIOMMC_CONFIGFS
|
||||
+ config_group_init(&gpiommc_subsys.su_group);
|
||||
+ err = configfs_register_subsystem(&gpiommc_subsys);
|
||||
+ if (err) {
|
||||
+ platform_driver_unregister(&gpiommc_plat_driver);
|
||||
+ return err;
|
||||
+ }
|
||||
+#endif /* CONFIG_GPIOMMC_CONFIGFS */
|
||||
+
|
||||
+ return 0;
|
||||
+}
|
||||
+module_init(gpiommc_modinit);
|
||||
+
|
||||
+static void __exit gpiommc_modexit(void)
|
||||
+{
|
||||
+#ifdef CONFIG_GPIOMMC_CONFIGFS
|
||||
+ configfs_unregister_subsystem(&gpiommc_subsys);
|
||||
+#endif
|
||||
+ platform_driver_unregister(&gpiommc_plat_driver);
|
||||
+}
|
||||
+module_exit(gpiommc_modexit);
|
||||
--- a/drivers/mmc/host/Kconfig
|
||||
+++ b/drivers/mmc/host/Kconfig
|
||||
@@ -130,3 +130,27 @@
|
||||
|
||||
If unsure, or if your system has no SPI master driver, say N.
|
||||
|
||||
+config GPIOMMC
|
||||
+ tristate "MMC/SD over GPIO-based SPI"
|
||||
+ depends on MMC && MMC_SPI && SPI_GPIO
|
||||
+ help
|
||||
+ This driver hooks up the mmc_spi and spi_gpio modules so that
|
||||
+ MMC/SD cards can be used on a GPIO based bus by bitbanging
|
||||
+ the SPI protocol in software.
|
||||
+
|
||||
+ This driver provides a configfs interface to dynamically create
|
||||
+ and destroy GPIO-based MMC/SD card devices. It also provides
|
||||
+ a platform device interface API.
|
||||
+ See Documentation/gpiommc.txt for details.
|
||||
+
|
||||
+ The module will be called gpiommc.
|
||||
+
|
||||
+ If unsure, say N.
|
||||
+
|
||||
+config GPIOMMC_CONFIGFS
|
||||
+ bool
|
||||
+ depends on GPIOMMC && CONFIGFS_FS
|
||||
+ default y
|
||||
+ help
|
||||
+ This option automatically enables configfs support for gpiommc
|
||||
+ if configfs is available.
|
||||
--- a/drivers/mmc/host/Makefile
|
||||
+++ b/drivers/mmc/host/Makefile
|
||||
@@ -17,4 +17,4 @@
|
||||
obj-$(CONFIG_MMC_AT91) += at91_mci.o
|
||||
obj-$(CONFIG_MMC_TIFM_SD) += tifm_sd.o
|
||||
obj-$(CONFIG_MMC_SPI) += mmc_spi.o
|
||||
-
|
||||
+obj-$(CONFIG_GPIOMMC) += gpiommc.o
|
||||
--- /dev/null
|
||||
+++ b/include/linux/mmc/gpiommc.h
|
||||
@@ -0,0 +1,71 @@
|
||||
+/*
|
||||
+ * Device driver for MMC/SD cards driven over a GPIO bus.
|
||||
+ *
|
||||
+ * Copyright (c) 2008 Michael Buesch
|
||||
+ *
|
||||
+ * Licensed under the GNU/GPL version 2.
|
||||
+ */
|
||||
+#ifndef LINUX_GPIOMMC_H_
|
||||
+#define LINUX_GPIOMMC_H_
|
||||
+
|
||||
+#include <linux/types.h>
|
||||
+
|
||||
+
|
||||
+#define GPIOMMC_MAX_NAMELEN 15
|
||||
+#define GPIOMMC_MAX_NAMELEN_STR __stringify(GPIOMMC_MAX_NAMELEN)
|
||||
+
|
||||
+/**
|
||||
+ * struct gpiommc_pins - Hardware pin assignments
|
||||
+ *
|
||||
+ * @gpio_di: The GPIO number of the DATA IN pin
|
||||
+ * @gpio_do: The GPIO number of the DATA OUT pin
|
||||
+ * @gpio_clk: The GPIO number of the CLOCK pin
|
||||
+ * @gpio_cs: The GPIO number of the CHIPSELECT pin
|
||||
+ * @cs_activelow: If true, the chip is considered selected if @gpio_cs is low.
|
||||
+ */
|
||||
+struct gpiommc_pins {
|
||||
+ unsigned int gpio_di;
|
||||
+ unsigned int gpio_do;
|
||||
+ unsigned int gpio_clk;
|
||||
+ unsigned int gpio_cs;
|
||||
+ bool cs_activelow;
|
||||
+};
|
||||
+
|
||||
+/**
|
||||
+ * struct gpiommc_platform_data - Platform data for a MMC-over-SPI-GPIO device.
|
||||
+ *
|
||||
+ * @name: The unique name string of the device.
|
||||
+ * @pins: The hardware pin assignments.
|
||||
+ * @mode: The hardware mode. This is either SPI_MODE_0,
|
||||
+ * SPI_MODE_1, SPI_MODE_2 or SPI_MODE_3. See the SPI documentation.
|
||||
+ * @no_spi_delay: Do not use delays in the lowlevel SPI bitbanging code.
|
||||
+ * This is not standards compliant, but may be required for some
|
||||
+ * embedded machines to gain reasonable speed.
|
||||
+ * @max_bus_speed: The maximum speed of the SPI bus, in Hertz.
|
||||
+ */
|
||||
+struct gpiommc_platform_data {
|
||||
+ char name[GPIOMMC_MAX_NAMELEN + 1];
|
||||
+ struct gpiommc_pins pins;
|
||||
+ u8 mode;
|
||||
+ bool no_spi_delay;
|
||||
+ unsigned int max_bus_speed;
|
||||
+};
|
||||
+
|
||||
+/**
|
||||
+ * GPIOMMC_PLATDEV_NAME - The platform device name string.
|
||||
+ *
|
||||
+ * The name string that has to be used for platform_device_alloc
|
||||
+ * when allocating a gpiommc device.
|
||||
+ */
|
||||
+#define GPIOMMC_PLATDEV_NAME "gpiommc"
|
||||
+
|
||||
+/**
|
||||
+ * gpiommc_next_id - Get another platform device ID number.
|
||||
+ *
|
||||
+ * This returns the next platform device ID number that has to be used
|
||||
+ * for platform_device_alloc. The ID is opaque and should not be used for
|
||||
+ * anything else.
|
||||
+ */
|
||||
+int gpiommc_next_id(void);
|
||||
+
|
||||
+#endif /* LINUX_GPIOMMC_H_ */
|
||||
--- /dev/null
|
||||
+++ b/Documentation/gpiommc.txt
|
||||
@@ -0,0 +1,97 @@
|
||||
+GPIOMMC - Driver for an MMC/SD card on a bitbanging GPIO SPI bus
|
||||
+================================================================
|
||||
+
|
||||
+The gpiommc module hooks up the mmc_spi and spi_gpio modules for running an
|
||||
+MMC or SD card on GPIO pins.
|
||||
+
|
||||
+Two interfaces for registering a new MMC/SD card device are provided:
|
||||
+A static platform-device based mechanism and a dynamic configfs based interface.
|
||||
+
|
||||
+
|
||||
+Registering devices via platform-device
|
||||
+=======================================
|
||||
+
|
||||
+The platform-device interface is used for registering MMC/SD devices that are
|
||||
+part of the hardware platform. This is most useful only for embedded machines
|
||||
+with MMC/SD devices statically connected to the platform GPIO bus.
|
||||
+
|
||||
+The data structures are declared in <linux/mmc/gpiommc.h>.
|
||||
+
|
||||
+To register a new device, define an instance of struct gpiommc_platform_data.
|
||||
+This structure holds any information about how the device is hooked up to the
|
||||
+GPIO pins and what hardware modes the device supports. See the docbook-style
|
||||
+documentation in the header file for more information on the struct fields.
|
||||
+
|
||||
+Then allocate a new instance of a platform device by doing:
|
||||
+
|
||||
+ pdev = platform_device_alloc(GPIOMMC_PLATDEV_NAME, gpiommc_next_id());
|
||||
+
|
||||
+This will allocate the platform device data structures and hook it up to the
|
||||
+gpiommc driver.
|
||||
+Then add the gpiommc_platform_data to the platform device.
|
||||
+
|
||||
+ err = platform_device_add_data(pdev, pdata, sizeof(struct gpiommc_platform_data));
|
||||
+
|
||||
+You may free the local instance of struct gpiommc_platform_data now. (So the
|
||||
+struct may be allocated on the stack, too).
|
||||
+Now simply register the platform device.
|
||||
+
|
||||
+ err = platform_device_add(pdev);
|
||||
+
|
||||
+Done. The gpiommc probe routine will be invoked now and you should see a kernel
|
||||
+log message for the added device.
|
||||
+
|
||||
+
|
||||
+Registering devices via configfs
|
||||
+================================
|
||||
+
|
||||
+MMC/SD cards connected via GPIO often are a pretty dynamic thing, as for example
|
||||
+selfmade hacks for soldering an MMC/SD card to standard GPIO pins on embedded
|
||||
+hardware are a common situation.
|
||||
+So we provide a dynamic interface to conveniently handle adding and removing
|
||||
+devices from userspace, without the need to recompile the kernel.
|
||||
+
|
||||
+The "gpiommc" subdirectory at the configfs mountpoint is used for handling
|
||||
+the dynamic configuration.
|
||||
+
|
||||
+To create a new device, it must first be allocated with mkdir.
|
||||
+The following command will allocate a device named "my_mmc":
|
||||
+ mkdir /config/gpiommc/my_mmc
|
||||
+
|
||||
+There are several configuration files available in the new
|
||||
+/config/gpiommc/my_mmc/ directory:
|
||||
+
|
||||
+gpio_data_in = The SPI data-IN GPIO pin number.
|
||||
+gpio_data_out = The SPI data-OUT GPIO pin number.
|
||||
+gpio_clock = The SPI Clock GPIO pin number.
|
||||
+gpio_chipselect = The SPI Chipselect GPIO pin number.
|
||||
+gpio_chipselect_activelow = Boolean. If 0, Chipselect is active-HIGH.
|
||||
+ If 1, Chipselect is active-LOW.
|
||||
+spi_mode = The SPI data mode. Can be 0-3.
|
||||
+spi_delay = Enable all delays in the lowlevel bitbanging.
|
||||
+max_bus_speed = The maximum SPI bus speed. In Hertz.
|
||||
+
|
||||
+register = Not a configuration parameter.
|
||||
+ Used to register the configured card
|
||||
+ with the kernel.
|
||||
+
|
||||
+The device must first get configured and then registered by writing "1" to
|
||||
+the "register" file.
|
||||
+The configuration parameters "gpio_data_in", "gpio_data_out", "gpio_clock"
|
||||
+and "gpio_chipselect" are essential and _must_ be configured before writing
|
||||
+"1" to the "register" file. The registration will fail, otherwise.
|
||||
+
|
||||
+The default values for the other parameters are:
|
||||
+gpio_chipselect_activelow = 1 (CS active-LOW)
|
||||
+spi_mode = 0 (SPI_MODE_0)
|
||||
+spi_delay = 1 (enabled)
|
||||
+max_bus_speed = 5000000 (5 Mhz)
|
||||
+
|
||||
+Configuration values can not be changed after registration. To unregister
|
||||
+the device, write a "0" to the "register" file. The configuration can be
|
||||
+changed again after unregistering.
|
||||
+
|
||||
+To completely remove the device, simply rmdir the directory
|
||||
+(/config/gpiommc/my_mmc in this example).
|
||||
+There's no need to first unregister the device before removing it. That will
|
||||
+be done automatically.
|
||||
--- a/MAINTAINERS
|
||||
+++ b/MAINTAINERS
|
||||
@@ -1818,6 +1818,11 @@
|
||||
W: http://gigaset307x.sourceforge.net/
|
||||
S: Maintained
|
||||
|
||||
+GPIOMMC DRIVER
|
||||
+P: Michael Buesch
|
||||
+M: mb@bu3sch.de
|
||||
+S: Maintained
|
||||
+
|
||||
HARDWARE MONITORING
|
||||
P: Mark M. Hoffman
|
||||
M: mhoffman@lightlink.com
|
||||
@ -0,0 +1,58 @@ |
||||
The gpiommc configfs context structure needs locking, as configfs
|
||||
does not lock access between files.
|
||||
|
||||
--- a/drivers/mmc/host/gpiommc.c
|
||||
+++ b/drivers/mmc/host/gpiommc.c
|
||||
@@ -143,6 +143,8 @@
|
||||
struct platform_device *pdev;
|
||||
/* The configuration */
|
||||
struct gpiommc_platform_data pdata;
|
||||
+ /* Mutex to protect this structure */
|
||||
+ struct mutex mutex;
|
||||
};
|
||||
|
||||
#define GPIO_INVALID -1
|
||||
@@ -233,6 +235,8 @@
|
||||
unsigned int gpio;
|
||||
int err = 0;
|
||||
|
||||
+ mutex_lock(&dev->mutex);
|
||||
+
|
||||
if (attr == &gpiommc_attr_DI) {
|
||||
gpio = dev->pdata.pins.gpio_di;
|
||||
if (gpio == GPIO_INVALID)
|
||||
@@ -293,6 +297,8 @@
|
||||
WARN_ON(1);
|
||||
err = -ENOSYS;
|
||||
out:
|
||||
+ mutex_unlock(&dev->mutex);
|
||||
+
|
||||
return err ? err : count;
|
||||
}
|
||||
|
||||
@@ -352,6 +358,8 @@
|
||||
int err = -EINVAL;
|
||||
unsigned long data;
|
||||
|
||||
+ mutex_lock(&dev->mutex);
|
||||
+
|
||||
if (attr == &gpiommc_attr_register) {
|
||||
err = strict_strtoul(page, 10, &data);
|
||||
if (err)
|
||||
@@ -477,6 +485,8 @@
|
||||
WARN_ON(1);
|
||||
err = -ENOSYS;
|
||||
out:
|
||||
+ mutex_unlock(&dev->mutex);
|
||||
+
|
||||
return err ? err : count;
|
||||
}
|
||||
|
||||
@@ -513,6 +523,7 @@
|
||||
if (!dev)
|
||||
return NULL;
|
||||
|
||||
+ mutex_init(&dev->mutex);
|
||||
config_item_init_type_name(&dev->item, name,
|
||||
&gpiommc_dev_ci_type);
|
||||
|
||||
Loading…
Reference in new issue