mirror of
git://projects.qi-hardware.com/openwrt-xburst.git
synced 2024-12-27 06:22:03 +02:00
0f80ce2088
git-svn-id: svn://svn.openwrt.org/openwrt/trunk@13135 3c298f89-4303-0410-b956-a3cf2f4a3e73
377 lines
10 KiB
Diff
377 lines
10 KiB
Diff
--- /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 SPI_MASTER && 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
|
|
@@ -3795,6 +3795,11 @@ L: cbe-oss-dev@ozlabs.org
|
|
W: http://www.ibm.com/developerworks/power/cell/
|
|
S: Supported
|
|
|
|
+SPI GPIO MASTER DRIVER
|
|
+P: Michael Buesch
|
|
+M: mb@bu3sch.de
|
|
+S: Maintained
|
|
+
|
|
STABLE BRANCH:
|
|
P: Greg Kroah-Hartman
|
|
M: greg@kroah.com
|