move spi_gpio driver into the kernel, clean-up SPI modules

SVN-Revision: 10844

1 files changed, 242 insertions, 0 deletions

diff --git a/target/linux/generic-2.6/files/drivers/spi/spi_gpio.c b/target/linux/generic-2.6/files/drivers/spi/spi_gpio.c
new file mode 100644
index 0000000..31048ac
--- /dev/null
+++ b/target/linux/generic-2.6/files/drivers/spi/spi_gpio.c
@@ -0,0 +1,242 @@
+/*
+ * 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");