diff options
Diffstat (limited to 'target/linux/generic-2.6/patches-2.6.28/921-gpio_spi_driver.patch')
| -rw-r--r-- | target/linux/generic-2.6/patches-2.6.28/921-gpio_spi_driver.patch | 376 |
1 files changed, 376 insertions, 0 deletions
diff --git a/target/linux/generic-2.6/patches-2.6.28/921-gpio_spi_driver.patch b/target/linux/generic-2.6/patches-2.6.28/921-gpio_spi_driver.patch new file mode 100644 index 0000000..d55eda6 --- /dev/null +++ b/target/linux/generic-2.6/patches-2.6.28/921-gpio_spi_driver.patch @@ -0,0 +1,376 @@ +--- /dev/null ++++ b/include/linux/spi/spi_gpio.h +@@ -0,0 +1,73 @@ ++/* ++ * spi_gpio interface to platform code ++ * ++ * Copyright (c) 2008 Piotr Skamruk ++ * Copyright (c) 2008 Michael Buesch ++ * ++ * 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; ++}; ++ ++/** ++ * SPI_GPIO_PLATDEV_NAME - The platform device name string. ++ * ++ * The name string that has to be used for platform_device_alloc ++ * when allocating a spi-gpio device. ++ */ ++#define SPI_GPIO_PLATDEV_NAME "spi-gpio" ++ ++/** ++ * spi_gpio_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 spi_gpio_next_id(void); ++ ++#endif /* _LINUX_SPI_SPI_GPIO */ +--- /dev/null ++++ b/drivers/spi/spi_gpio.c +@@ -0,0 +1,251 @@ ++/* ++ * 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> ++#include <linux/gpio.h> ++#include <asm/atomic.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_PLATDEV_NAME, ++ .owner = THIS_MODULE, ++ }, ++ .probe = spi_gpio_probe, ++ .remove = __devexit_p(spi_gpio_remove), ++}; ++ ++int spi_gpio_next_id(void) ++{ ++ static atomic_t counter = ATOMIC_INIT(-1); ++ ++ return atomic_inc_return(&counter); ++} ++EXPORT_SYMBOL(spi_gpio_next_id); ++ ++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 bitbanging SPI driver"); ++MODULE_LICENSE("GPL v2"); +--- a/drivers/spi/Kconfig ++++ b/drivers/spi/Kconfig +@@ -100,6 +100,19 @@ config SPI_BUTTERFLY + inexpensive battery powered microcontroller evaluation board. + This same cable can be used to flash new firmware. + ++config SPI_GPIO ++ tristate "GPIO API based bitbanging SPI controller" ++ depends on SPI_MASTER && GENERIC_GPIO ++ select SPI_BITBANG ++ help ++ This is a platform driver that can be used for bitbanging ++ an SPI bus over GPIO pins. ++ Select this if you have any SPI device that is connected via ++ GPIO pins. ++ The module will be called spi_gpio. ++ ++ If unsure, say N. ++ + config SPI_IMX + tristate "Freescale iMX SPI controller" + depends on ARCH_IMX && EXPERIMENTAL +--- a/drivers/spi/Makefile ++++ b/drivers/spi/Makefile +@@ -16,6 +16,7 @@ obj-$(CONFIG_SPI_BFIN) += spi_bfin5xx. + obj-$(CONFIG_SPI_BITBANG) += spi_bitbang.o + obj-$(CONFIG_SPI_AU1550) += au1550_spi.o + obj-$(CONFIG_SPI_BUTTERFLY) += spi_butterfly.o ++obj-$(CONFIG_SPI_GPIO) += spi_gpio.o + obj-$(CONFIG_SPI_IMX) += spi_imx.o + obj-$(CONFIG_SPI_LM70_LLP) += spi_lm70llp.o + obj-$(CONFIG_SPI_PXA2XX) += pxa2xx_spi.o +--- a/MAINTAINERS ++++ b/MAINTAINERS +@@ -4017,6 +4017,11 @@ M: jbglaw@lug-owl.de + L: linux-kernel@vger.kernel.org + S: Maintained + ++SPI GPIO MASTER DRIVER ++P: Michael Buesch ++M: mb@bu3sch.de ++S: Maintained ++ + STABLE BRANCH + P: Greg Kroah-Hartman + M: greg@kroah.com |