[PATCH 1/2] S3C64XX: Add SPI-GPIO based driver.
Matt Hsu
matt_hsu at openmoko.org
Tue Jan 20 12:09:32 CET 2009
This driver drives SPI bus over generic GPIO on s3c64xx.
Signed-off-by: Matt Hsu <matt_hsu at openmoko.org>
---
arch/arm/mach-s3c6410/include/mach/spi-gpio.h | 36 +++++
drivers/spi/Kconfig | 9 +
drivers/spi/Makefile | 1 +
drivers/spi/spi_s3c64xx_gpio.c | 201 +++++++++++++++++++++++++
4 files changed, 247 insertions(+), 0 deletions(-)
create mode 100644 arch/arm/mach-s3c6410/include/mach/spi-gpio.h
create mode 100644 drivers/spi/spi_s3c64xx_gpio.c
diff --git a/arch/arm/mach-s3c6410/include/mach/spi-gpio.h b/arch/arm/mach-s3c6410/include/mach/spi-gpio.h
new file mode 100644
index 0000000..35716ff
--- /dev/null
+++ b/arch/arm/mach-s3c6410/include/mach/spi-gpio.h
@@ -0,0 +1,36 @@
+/* arch/arm/mach-s3c6400/include/mach/spi-gpio.h
+ *
+ * Copyright (c) 2006 Simtec Electronics
+ * Ben Dooks <ben at simtec.co.uk>
+ *
+ * S3C64XX - SPI Controller platfrom_device info
+ *
+ * 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 __ASM_ARCH_SPIGPIO_H
+#define __ASM_ARCH_SPIGPIO_H __FILE__
+
+struct s3c64xx_spigpio_info {
+ unsigned long pin_clk;
+ unsigned long pin_mosi;
+ unsigned long pin_miso;
+
+ int bus_num;
+ int num_chipselect;
+
+ /*
+ * FIXME: board_size and board_info DO NOT belong here.
+ * These were already removed upstream... but we still rely on them
+ * so leave for now and revisit this.
+ */
+ unsigned long board_size;
+ struct spi_board_info *board_info;
+
+ void (*chip_select)(struct s3c64xx_spigpio_info *spi, int csid, int cs);
+};
+
+
+#endif /* __ASM_ARCH_SPIGPIO_H */
diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig
index b9d0efb..c713add 100644
--- a/drivers/spi/Kconfig
+++ b/drivers/spi/Kconfig
@@ -243,6 +243,15 @@ config SPI_TLE62X0
sysfs interface, with each line presented as a kind of GPIO
exposing both switch control and diagnostic feedback.
+config SPI_S3C64XX_GPIO
+ tristate "Samsung S3C64XX series SPI by GPIO"
+ depends on ARCH_S3C64XX && EXPERIMENTAL
+ select SPI_BITBANG
+ help
+ SPI driver for Samsung S3C64XX series ARM SoCs using
+ GPIO lines to provide the SPI bus. This can be used where
+ the inbuilt hardware cannot provide the transfer mode, or
+ where the board is using non hardware connected pins.
#
# Add new SPI protocol masters in alphabetical order above this line
#
diff --git a/drivers/spi/Makefile b/drivers/spi/Makefile
index ccf18de..a55fed7 100644
--- a/drivers/spi/Makefile
+++ b/drivers/spi/Makefile
@@ -29,6 +29,7 @@ obj-$(CONFIG_SPI_S3C24XX) += spi_s3c24xx.o
obj-$(CONFIG_SPI_TXX9) += spi_txx9.o
obj-$(CONFIG_SPI_XILINX) += xilinx_spi.o
obj-$(CONFIG_SPI_SH_SCI) += spi_sh_sci.o
+obj-$(CONFIG_SPI_S3C64XX_GPIO) += spi_s3c64xx_gpio.o
# ... add above this line ...
# SPI protocol drivers (device/link on bus)
diff --git a/drivers/spi/spi_s3c64xx_gpio.c b/drivers/spi/spi_s3c64xx_gpio.c
new file mode 100644
index 0000000..9ade147
--- /dev/null
+++ b/drivers/spi/spi_s3c64xx_gpio.c
@@ -0,0 +1,201 @@
+/* linux/drivers/spi/spi_s3c64xx_gpio.c
+ *
+ * Copyright (c) 2009 Openmoko Inc.
+ * Author: Matt Hsu <matt_hsu at openmoko.org>
+ *
+ * S3C64XX GPIO-SPI driver.
+ * This driver is based on spi_s3c24xx_gpio.c
+ *
+ * Copyright (c) 2006 Ben Dooks
+ * Copyright (c) 2006 Simtec Electronics
+ *
+ * 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 <plat/gpio-cfg.h>
+#include <mach/spi-gpio.h>
+
+struct s3c64xx_spigpio {
+ struct spi_bitbang bitbang;
+ struct s3c64xx_spigpio_info *info;
+ struct platform_device *dev;
+};
+
+static inline struct s3c64xx_spigpio *spidev_to_sg(struct spi_device *spi)
+{
+ return spi->controller_data;
+}
+
+static inline void setsck(struct spi_device *dev, int on)
+{
+ struct s3c64xx_spigpio *sg = spidev_to_sg(dev);
+ gpio_direction_output(sg->info->pin_clk, on ? 1 : 0);
+}
+
+static inline void setmosi(struct spi_device *dev, int on)
+{
+ struct s3c64xx_spigpio *sg = spidev_to_sg(dev);
+ gpio_direction_output(sg->info->pin_mosi, on ? 1 : 0);
+}
+
+static inline u32 getmiso(struct spi_device *dev)
+{
+ struct s3c64xx_spigpio *sg = spidev_to_sg(dev);
+ return gpio_direction_input(sg->info->pin_miso) ? 1 : 0;
+}
+
+#define spidelay(x) ndelay(x)
+
+#define EXPAND_BITBANG_TXRX
+#include <linux/spi/spi_bitbang.h>
+
+static u32 s3c64xx_spigpio_txrx_mode0(struct spi_device *spi,
+ unsigned nsecs, u32 word, u8 bits)
+{
+ return bitbang_txrx_be_cpha0(spi, nsecs, 0, word, bits);
+}
+
+static u32 s3c64xx_spigpio_txrx_mode1(struct spi_device *spi,
+ unsigned nsecs, u32 word, u8 bits)
+{
+ return bitbang_txrx_be_cpha1(spi, nsecs, 0, word, bits);
+}
+
+static u32 s3c64xx_spigpio_txrx_mode2(struct spi_device *spi,
+ unsigned nsecs, u32 word, u8 bits)
+{
+ return bitbang_txrx_be_cpha0(spi, nsecs, 1, word, bits);
+}
+
+static u32 s3c64xx_spigpio_txrx_mode3(struct spi_device *spi,
+ unsigned nsecs, u32 word, u8 bits)
+{
+ return bitbang_txrx_be_cpha1(spi, nsecs, 1, word, bits);
+}
+static void s3c64xx_spigpio_chipselect(struct spi_device *dev, int value)
+{
+ struct s3c64xx_spigpio *sg = spidev_to_sg(dev);
+
+ if (sg->info && sg->info->chip_select)
+ (sg->info->chip_select)(sg->info, dev->chip_select, value);
+}
+
+static int s3c64xx_spigpio_probe(struct platform_device *dev)
+{
+ struct s3c64xx_spigpio_info *info;
+ struct spi_master *master;
+ struct s3c64xx_spigpio *spi;
+
+ int ret;
+ int i;
+
+ master = spi_alloc_master(&dev->dev, sizeof(struct s3c64xx_spigpio));
+ if (master == NULL) {
+ dev_err(&dev->dev, "failed to allocate spi master\n");
+ ret = -ENOMEM;
+ goto err;
+ }
+
+ spi = spi_master_get_devdata(master);
+
+ /* copy in the platform data */
+ info = spi->info = dev->dev.platform_data;
+
+ master->num_chipselect = info->num_chipselect;
+
+ /* setup spi bitbang adaptor */
+ spi->bitbang.master = spi_master_get(master);
+ spi->bitbang.master->bus_num = info->bus_num;
+
+ spi->bitbang.chipselect = s3c64xx_spigpio_chipselect;
+
+ spi->bitbang.txrx_word[SPI_MODE_0] = s3c64xx_spigpio_txrx_mode0;
+ spi->bitbang.txrx_word[SPI_MODE_1] = s3c64xx_spigpio_txrx_mode1;
+ spi->bitbang.txrx_word[SPI_MODE_2] = s3c64xx_spigpio_txrx_mode2;
+ spi->bitbang.txrx_word[SPI_MODE_3] = s3c64xx_spigpio_txrx_mode3;
+
+ /* set state of spi pins. */
+ gpio_direction_output(info->pin_clk, 0);
+ s3c_gpio_cfgpin(info->pin_clk, S3C_GPIO_OUTPUT);
+
+ ret = spi_bitbang_start(&spi->bitbang);
+ if (ret)
+ goto err_no_bitbang;
+
+ /* register the chips to go with the board */
+ for (i = 0; i < spi->info->board_size; i++) {
+ struct spi_device *spidev;
+
+ dev_info(&dev->dev, "registering %p: %s\n",
+ &spi->info->board_info[i],
+ spi->info->board_info[i].modalias);
+
+ spi->info->board_info[i].controller_data = spi;
+ spidev = spi_new_device(master, spi->info->board_info + i);
+ if (spidev)
+ spidev->max_speed_hz =
+ spi->info->board_info[i].max_speed_hz;
+ }
+
+ return 0;
+
+ err_no_bitbang:
+ spi_master_put(spi->bitbang.master);
+ err:
+ return ret;
+}
+
+static int s3c64xx_spigpio_remove(struct platform_device *dev)
+{
+ struct s3c64xx_spigpio *sp = platform_get_drvdata(dev);
+
+ spi_bitbang_stop(&sp->bitbang);
+ spi_master_put(sp->bitbang.master);
+
+ return 0;
+}
+
+#define s3c64xx_spigpio_suspend NULL
+#define s3c64xx_spigpio_resume NULL
+
+static struct platform_driver s3c64xx_spigpio_drv = {
+ .probe = s3c64xx_spigpio_probe,
+ .remove = s3c64xx_spigpio_remove,
+ .suspend = s3c64xx_spigpio_suspend,
+ .resume = s3c64xx_spigpio_resume,
+ .driver = {
+ .name = "spi_s3c64xx_gpio",
+ .owner = THIS_MODULE,
+ },
+};
+
+static int __init s3c64xx_spigpio_init(void)
+{
+ return platform_driver_register(&s3c64xx_spigpio_drv);
+}
+
+static void __exit s3c64xx_spigpio_exit(void)
+{
+ platform_driver_unregister(&s3c64xx_spigpio_drv);
+}
+
+module_init(s3c64xx_spigpio_init);
+module_exit(s3c64xx_spigpio_exit);
+
+MODULE_DESCRIPTION("S3C64XX GPIO-SPI Driver");
+MODULE_AUTHOR("Matt Hsu, <matt_hsu at openmoko.org>");
+MODULE_LICENSE("GPLv2");
--
1.5.6.5
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