Initial import

1 files changed, 197 insertions, 0 deletions

diff --git a/drivers/spi/spi-sh-sci.c b/drivers/spi/spi-sh-sci.c
new file mode 100644
index 000000000..a9beeeed8
--- /dev/null
+++ b/drivers/spi/spi-sh-sci.c
@@ -0,0 +1,197 @@
+/*
+ * SH SCI SPI interface
+ *
+ * Copyright (c) 2008 Magnus Damm
+ *
+ * Based on S3C24XX GPIO based SPI driver, which is:
+ *   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/delay.h>
+#include <linux/spinlock.h>
+#include <linux/platform_device.h>
+
+#include <linux/spi/spi.h>
+#include <linux/spi/spi_bitbang.h>
+#include <linux/module.h>
+
+#include <asm/spi.h>
+#include <asm/io.h>
+
+struct sh_sci_spi {
+	struct spi_bitbang bitbang;
+
+	void __iomem *membase;
+	unsigned char val;
+	struct sh_spi_info *info;
+	struct platform_device *dev;
+};
+
+#define SCSPTR(sp)	(sp->membase + 0x1c)
+#define PIN_SCK		(1 << 2)
+#define PIN_TXD		(1 << 0)
+#define PIN_RXD		PIN_TXD
+#define PIN_INIT	((1 << 1) | (1 << 3) | PIN_SCK | PIN_TXD)
+
+static inline void setbits(struct sh_sci_spi *sp, int bits, int on)
+{
+	/*
+	 * We are the only user of SCSPTR so no locking is required.
+	 * Reading bit 2 and 0 in SCSPTR gives pin state as input.
+	 * Writing the same bits sets the output value.
+	 * This makes regular read-modify-write difficult so we
+	 * use sp->val to keep track of the latest register value.
+	 */
+
+	if (on)
+		sp->val |= bits;
+	else
+		sp->val &= ~bits;
+
+	iowrite8(sp->val, SCSPTR(sp));
+}
+
+static inline void setsck(struct spi_device *dev, int on)
+{
+	setbits(spi_master_get_devdata(dev->master), PIN_SCK, on);
+}
+
+static inline void setmosi(struct spi_device *dev, int on)
+{
+	setbits(spi_master_get_devdata(dev->master), PIN_TXD, on);
+}
+
+static inline u32 getmiso(struct spi_device *dev)
+{
+	struct sh_sci_spi *sp = spi_master_get_devdata(dev->master);
+
+	return (ioread8(SCSPTR(sp)) & PIN_RXD) ? 1 : 0;
+}
+
+#define spidelay(x) ndelay(x)
+
+#include "spi-bitbang-txrx.h"
+
+static u32 sh_sci_spi_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 sh_sci_spi_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 sh_sci_spi_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 sh_sci_spi_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 sh_sci_spi_chipselect(struct spi_device *dev, int value)
+{
+	struct sh_sci_spi *sp = spi_master_get_devdata(dev->master);
+
+	if (sp->info->chip_select)
+		(sp->info->chip_select)(sp->info, dev->chip_select, value);
+}
+
+static int sh_sci_spi_probe(struct platform_device *dev)
+{
+	struct resource	*r;
+	struct spi_master *master;
+	struct sh_sci_spi *sp;
+	int ret;
+
+	master = spi_alloc_master(&dev->dev, sizeof(struct sh_sci_spi));
+	if (master == NULL) {
+		dev_err(&dev->dev, "failed to allocate spi master\n");
+		ret = -ENOMEM;
+		goto err0;
+	}
+
+	sp = spi_master_get_devdata(master);
+
+	platform_set_drvdata(dev, sp);
+	sp->info = dev_get_platdata(&dev->dev);
+	if (!sp->info) {
+		dev_err(&dev->dev, "platform data is missing\n");
+		ret = -ENOENT;
+		goto err1;
+	}
+
+	/* setup spi bitbang adaptor */
+	sp->bitbang.master = master;
+	sp->bitbang.master->bus_num = sp->info->bus_num;
+	sp->bitbang.master->num_chipselect = sp->info->num_chipselect;
+	sp->bitbang.chipselect = sh_sci_spi_chipselect;
+
+	sp->bitbang.txrx_word[SPI_MODE_0] = sh_sci_spi_txrx_mode0;
+	sp->bitbang.txrx_word[SPI_MODE_1] = sh_sci_spi_txrx_mode1;
+	sp->bitbang.txrx_word[SPI_MODE_2] = sh_sci_spi_txrx_mode2;
+	sp->bitbang.txrx_word[SPI_MODE_3] = sh_sci_spi_txrx_mode3;
+
+	r = platform_get_resource(dev, IORESOURCE_MEM, 0);
+	if (r == NULL) {
+		ret = -ENOENT;
+		goto err1;
+	}
+	sp->membase = ioremap(r->start, resource_size(r));
+	if (!sp->membase) {
+		ret = -ENXIO;
+		goto err1;
+	}
+	sp->val = ioread8(SCSPTR(sp));
+	setbits(sp, PIN_INIT, 1);
+
+	ret = spi_bitbang_start(&sp->bitbang);
+	if (!ret)
+		return 0;
+
+	setbits(sp, PIN_INIT, 0);
+	iounmap(sp->membase);
+ err1:
+	spi_master_put(sp->bitbang.master);
+ err0:
+	return ret;
+}
+
+static int sh_sci_spi_remove(struct platform_device *dev)
+{
+	struct sh_sci_spi *sp = platform_get_drvdata(dev);
+
+	spi_bitbang_stop(&sp->bitbang);
+	setbits(sp, PIN_INIT, 0);
+	iounmap(sp->membase);
+	spi_master_put(sp->bitbang.master);
+	return 0;
+}
+
+static struct platform_driver sh_sci_spi_drv = {
+	.probe		= sh_sci_spi_probe,
+	.remove		= sh_sci_spi_remove,
+	.driver		= {
+		.name	= "spi_sh_sci",
+	},
+};
+module_platform_driver(sh_sci_spi_drv);
+
+MODULE_DESCRIPTION("SH SCI SPI Driver");
+MODULE_AUTHOR("Magnus Damm <damm@opensource.se>");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:spi_sh_sci");