summaryrefslogtreecommitdiffstats
path: root/drivers/spi/spi-s3c24xx-gpio.c
diff options
context:
space:
mode:
Diffstat (limited to 'drivers/spi/spi-s3c24xx-gpio.c')
-rw-r--r--drivers/spi/spi-s3c24xx-gpio.c200
1 files changed, 200 insertions, 0 deletions
diff --git a/drivers/spi/spi-s3c24xx-gpio.c b/drivers/spi/spi-s3c24xx-gpio.c
new file mode 100644
index 000000000000..2d3c085930fe
--- /dev/null
+++ b/drivers/spi/spi-s3c24xx-gpio.c
@@ -0,0 +1,200 @@
+/*
+ * 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/gpio.h>
+
+#include <linux/spi/spi.h>
+#include <linux/spi/spi_bitbang.h>
+
+#include <mach/regs-gpio.h>
+#include <mach/spi-gpio.h>
+#include <mach/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_master_get_devdata(spi->master);
+}
+
+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)
+
+#include "spi-bitbang-txrx.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, 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, 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, 0, 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, 0, 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 s3c2410_spigpio_info *info;
+ struct spi_master *master;
+ struct s3c2410_spigpio *sp;
+ int ret;
+
+ 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 */
+ info = sp->info = dev->dev.platform_data;
+
+ /* setup spi bitbang adaptor */
+ sp->bitbang.master = spi_master_get(master);
+ sp->bitbang.master->bus_num = info->bus_num;
+ sp->bitbang.master->num_chipselect = info->num_chipselect;
+ 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, always assume that the clock is
+ * available, but do check the MOSI and MISO. */
+ s3c2410_gpio_setpin(info->pin_clk, 0);
+ s3c2410_gpio_cfgpin(info->pin_clk, S3C2410_GPIO_OUTPUT);
+
+ if (info->pin_mosi < S3C2410_GPH10) {
+ s3c2410_gpio_setpin(info->pin_mosi, 0);
+ s3c2410_gpio_cfgpin(info->pin_mosi, S3C2410_GPIO_OUTPUT);
+ }
+
+ if (info->pin_miso != S3C2410_GPA0 && info->pin_miso < S3C2410_GPH10)
+ s3c2410_gpio_cfgpin(info->pin_miso, S3C2410_GPIO_INPUT);
+
+ ret = spi_bitbang_start(&sp->bitbang);
+ if (ret)
+ goto err_no_bitbang;
+
+ 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
+
+/* work with hotplug and coldplug */
+MODULE_ALIAS("platform:spi_s3c24xx_gpio");
+
+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");