[ar71xx] add another SPI controller driver for the earlier AP83 boards

git-svn-id: svn://svn.openwrt.org/openwrt/trunk@16315 3c298f89-4303-0410-b956-a3cf2f4a3e73

1 files changed, 282 insertions, 0 deletions

diff --git a/target/linux/ar71xx/files/drivers/spi/ap83_spi.c b/target/linux/ar71xx/files/drivers/spi/ap83_spi.c
new file mode 100644
index 0000000000..c93070d50a
--- /dev/null
+++ b/target/linux/ar71xx/files/drivers/spi/ap83_spi.c
@@ -0,0 +1,282 @@
+/*
+ * Atheros AP83 board specific SPI Controller driver
+ *
+ * Copyright (C) 2009 Gabor Juhos <juhosg@openwrt.org>
+ *
+ * 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/io.h>
+#include <linux/spi/spi.h>
+#include <linux/spi/spi_bitbang.h>
+#include <linux/bitops.h>
+#include <linux/gpio.h>
+
+#include <asm/mach-ar71xx/ar71xx.h>
+#include <asm/mach-ar71xx/platform.h>
+
+#define DRV_DESC	"Atheros AP83 board SPI Controller driver"
+#define DRV_VERSION	"0.1.0"
+#define DRV_NAME	"ap83-spi"
+
+#define AP83_SPI_CLK_HIGH	(1 << 23)
+#define AP83_SPI_CLK_LOW	0
+#define AP83_SPI_MOSI_HIGH	(1 << 22)
+#define AP83_SPI_MOSI_LOW	0
+
+#define AP83_SPI_GPIO_CS	1
+#define AP83_SPI_GPIO_MISO	3
+
+struct ap83_spi {
+	struct	spi_bitbang 	bitbang;
+	void __iomem 		*base;
+	u32			addr;
+
+	struct platform_device	*pdev;
+};
+
+static inline u32 ap83_spi_rr(struct ap83_spi *sp, u32 reg)
+{
+	return __raw_readl(sp->base + reg);
+}
+
+static inline struct ap83_spi *spidev_to_sp(struct spi_device *spi)
+{
+	return spi_master_get_devdata(spi->master);
+}
+
+static inline void setsck(struct spi_device *spi, int val)
+{
+	struct ap83_spi *sp = spidev_to_sp(spi);
+
+	if (val)
+		sp->addr |= AP83_SPI_CLK_HIGH;
+	else
+		sp->addr &= ~AP83_SPI_CLK_HIGH;
+
+	dev_dbg(&spi->dev, "addr=%08x,  SCK set to %s\n",
+		sp->addr, (val) ? "HIGH" : "LOW");
+
+	ap83_spi_rr(sp, sp->addr);
+}
+
+static inline void setmosi(struct spi_device *spi, int val)
+{
+	struct ap83_spi *sp = spidev_to_sp(spi);
+
+	if (val)
+		sp->addr |= AP83_SPI_MOSI_HIGH;
+	else
+		sp->addr &= ~AP83_SPI_MOSI_HIGH;
+
+	dev_dbg(&spi->dev, "addr=%08x, MOSI set to %s\n",
+		sp->addr, (val) ? "HIGH" : "LOW");
+
+	ap83_spi_rr(sp, sp->addr);
+}
+
+static inline u32 getmiso(struct spi_device *spi)
+{
+	u32 ret;
+
+	ret = gpio_get_value(AP83_SPI_GPIO_MISO) ? 1 : 0;
+	dev_dbg(&spi->dev, "get MISO: %d\n", ret);
+
+	return ret;
+}
+
+static inline void do_spidelay(struct spi_device *spi, unsigned nsecs)
+{
+	ndelay(nsecs);
+}
+
+static void ap83_spi_chipselect(struct spi_device *spi, int on)
+{
+	struct ap83_spi *sp = spidev_to_sp(spi);
+
+	dev_dbg(&spi->dev, "set CS to %d\n", (on) ? 0 : 1);
+
+	if (on) {
+		ar71xx_flash_acquire();
+
+		sp->addr = 0;
+		ap83_spi_rr(sp, sp->addr);
+
+		gpio_set_value(AP83_SPI_GPIO_CS, 0);
+	} else {
+		gpio_set_value(AP83_SPI_GPIO_CS, 1);
+		ar71xx_flash_release();
+	}
+}
+
+#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 ap83_spi_txrx_mode0(struct spi_device *spi,
+			       unsigned nsecs, u32 word, u8 bits)
+{
+	dev_dbg(&spi->dev, "TXRX0 word=%08x, bits=%u\n", word, bits);
+	return bitbang_txrx_be_cpha0(spi, nsecs, 0, word, bits);
+}
+
+static u32 ap83_spi_txrx_mode1(struct spi_device *spi,
+			       unsigned nsecs, u32 word, u8 bits)
+{
+	dev_dbg(&spi->dev, "TXRX1 word=%08x, bits=%u\n", word, bits);
+	return bitbang_txrx_be_cpha1(spi, nsecs, 0, word, bits);
+}
+
+static u32 ap83_spi_txrx_mode2(struct spi_device *spi,
+			       unsigned nsecs, u32 word, u8 bits)
+{
+	dev_dbg(&spi->dev, "TXRX2 word=%08x, bits=%u\n", word, bits);
+	return bitbang_txrx_be_cpha0(spi, nsecs, 1, word, bits);
+}
+
+static u32 ap83_spi_txrx_mode3(struct spi_device *spi,
+			       unsigned nsecs, u32 word, u8 bits)
+{
+	dev_dbg(&spi->dev, "TXRX3 word=%08x, bits=%u\n", word, bits);
+	return bitbang_txrx_be_cpha1(spi, nsecs, 1, word, bits);
+}
+
+static int ap83_spi_probe(struct platform_device *pdev)
+{
+	struct spi_master *master;
+	struct ap83_spi *sp;
+	struct ap83_spi_platform_data *pdata;
+	struct resource	*r;
+	int ret;
+
+	ret = gpio_request(AP83_SPI_GPIO_MISO, "spi-miso");
+	if (ret) {
+		dev_err(&pdev->dev, "gpio request failed for MISO\n");
+		return ret;
+	}
+
+	ret = gpio_request(AP83_SPI_GPIO_CS, "spi-cs");
+	if (ret) {
+		dev_err(&pdev->dev, "gpio request failed for CS\n");
+		goto err_free_miso;
+	}
+
+	ret = gpio_direction_input(AP83_SPI_GPIO_MISO);
+	if (ret) {
+		dev_err(&pdev->dev, "unable to set direction of MISO\n");
+		goto err_free_cs;
+	}
+
+	ret = gpio_direction_output(AP83_SPI_GPIO_CS, 0);
+	if (ret) {
+		dev_err(&pdev->dev, "unable to set direction of CS\n");
+		goto err_free_cs;
+	}
+
+	master = spi_alloc_master(&pdev->dev, sizeof(*sp));
+	if (master == NULL) {
+		dev_err(&pdev->dev, "failed to allocate spi master\n");
+		return -ENOMEM;
+	}
+
+	sp = spi_master_get_devdata(master);
+	platform_set_drvdata(pdev, sp);
+
+	pdata = pdev->dev.platform_data;
+
+	sp->bitbang.master = spi_master_get(master);
+	sp->bitbang.chipselect = ap83_spi_chipselect;
+	sp->bitbang.txrx_word[SPI_MODE_0] = ap83_spi_txrx_mode0;
+	sp->bitbang.txrx_word[SPI_MODE_1] = ap83_spi_txrx_mode1;
+	sp->bitbang.txrx_word[SPI_MODE_2] = ap83_spi_txrx_mode2;
+	sp->bitbang.txrx_word[SPI_MODE_3] = ap83_spi_txrx_mode3;
+
+	sp->bitbang.master->bus_num = pdev->id;
+	sp->bitbang.master->num_chipselect = 1;
+
+	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (r == NULL) {
+		ret = -ENOENT;
+		goto err_spi_put;
+	}
+
+	sp->base = ioremap_nocache(r->start, r->end - r->start + 1);
+	if (!sp->base) {
+		ret = -ENXIO;
+		goto err_spi_put;
+	}
+
+	ret = spi_bitbang_start(&sp->bitbang);
+	if (!ret)
+		goto err_unmap;
+
+	dev_info(&pdev->dev, "AP83 SPI adapter at %08x\n", r->start);
+
+	return 0;
+
+ err_unmap:
+	iounmap(sp->base);
+ err_spi_put:
+	platform_set_drvdata(pdev, NULL);
+	spi_master_put(sp->bitbang.master);
+
+ err_free_cs:
+	gpio_free(AP83_SPI_GPIO_CS);
+ err_free_miso:
+	gpio_free(AP83_SPI_GPIO_MISO);
+	return ret;
+}
+
+static int ap83_spi_remove(struct platform_device *pdev)
+{
+	struct ap83_spi *sp = platform_get_drvdata(pdev);
+
+	spi_bitbang_stop(&sp->bitbang);
+	iounmap(sp->base);
+	platform_set_drvdata(pdev, NULL);
+	spi_master_put(sp->bitbang.master);
+
+	return 0;
+}
+
+static struct platform_driver ap83_spi_drv = {
+	.probe		= ap83_spi_probe,
+	.remove		= ap83_spi_remove,
+	.driver		= {
+		.name	= DRV_NAME,
+		.owner	= THIS_MODULE,
+	},
+};
+
+static int __init ap83_spi_init(void)
+{
+	return platform_driver_register(&ap83_spi_drv);
+}
+module_init(ap83_spi_init);
+
+static void __exit ap83_spi_exit(void)
+{
+	platform_driver_unregister(&ap83_spi_drv);
+}
+module_exit(ap83_spi_exit);
+
+MODULE_ALIAS("platform:" DRV_NAME);
+MODULE_DESCRIPTION(DRV_DESC);
+MODULE_VERSION(DRV_VERSION);
+MODULE_AUTHOR("Gabor Juhos <juhosg@openwrt.org>");
+MODULE_LICENSE("GPL v2");