path: root/target/linux/cns21xx/patches-2.6.37/105-cns21xx-spi-driver.patch

--- a/include/linux/spi/spi.h
+++ b/include/linux/spi/spi.h
@@ -445,6 +445,8 @@ struct spi_transfer {
 	u16		delay_usecs;
 	u32		speed_hz;
 
+	unsigned	last_in_message_list;
+
 	struct list_head transfer_list;
 };
 
--- a/drivers/spi/Kconfig
+++ b/drivers/spi/Kconfig
@@ -167,6 +167,14 @@ config SPI_GPIO_OLD
 
 	  If unsure, say N.
 
+config SPI_CNS21XX
+	tristate "Cavium Netowrks CNS21xx SPI master"
+	depends on ARCH_CNS21XX && EXPERIMENTAL
+	select SPI_BITBANG
+	help
+	  This driver supports the buil-in SPI controller of the Cavium Networks
+	  CNS21xx SoCs.
+
 config SPI_IMX
 	tristate "Freescale i.MX SPI controllers"
 	depends on ARCH_MXC
--- a/drivers/spi/Makefile
+++ b/drivers/spi/Makefile
@@ -50,6 +50,7 @@ obj-$(CONFIG_SPI_SH_SCI)		+= spi_sh_sci.
 obj-$(CONFIG_SPI_SH_MSIOF)		+= spi_sh_msiof.o
 obj-$(CONFIG_SPI_STMP3XXX)		+= spi_stmp.o
 obj-$(CONFIG_SPI_NUC900)		+= spi_nuc900.o
+obj-$(CONFIG_SPI_CNS21XX)		+= spi_cns21xx.o
 
 # special build for s3c24xx spi driver with fiq support
 spi_s3c24xx_hw-y			:= spi_s3c24xx.o
--- a/drivers/spi/spi_bitbang.c
+++ b/drivers/spi/spi_bitbang.c
@@ -337,6 +337,13 @@ static void bitbang_work(struct work_str
 				 */
 				if (!m->is_dma_mapped)
 					t->rx_dma = t->tx_dma = 0;
+
+				if (t->transfer_list.next == &m->transfers) {
+					t->last_in_message_list = 1;
+				} else {
+					t->last_in_message_list = 0;
+				}
+
 				status = bitbang->txrx_bufs(spi, t);
 			}
 			if (status > 0)
--- /dev/null
+++ b/drivers/spi/spi_cns21xx.c
@@ -0,0 +1,520 @@
+/*
+ *  Copyright (c) 2008 Cavium Networks
+ *  Copyright (c) 2010 Gabor Juhos <juhosg@openwrt.org>
+ *
+ *  This file 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/init.h>
+#include <linux/spinlock.h>
+#include <linux/workqueue.h>
+#include <linux/interrupt.h>
+#include <linux/delay.h>
+#include <linux/errno.h>
+#include <linux/platform_device.h>
+#include <linux/io.h>
+#include <linux/spi/spi.h>
+#include <linux/spi/spi_bitbang.h>
+
+#include <mach/hardware.h>
+#include <mach/cns21xx.h>
+
+#define DRIVER_NAME	"cns21xx-spi"
+
+#ifdef CONFIG_CNS21XX_SPI_DEBUG
+#define DBG(fmt, args...)	pr_info("[CNS21XX_SPI_DEBUG]" fmt, ## args)
+#else
+#define DBG(fmt, args...)	do {} while (0)
+#endif /*  CNS21XX_SPI_DEBUG */
+
+#define SPI_REG_CFG			0x40
+#define SPI_REG_STAT			0x44
+#define SPI_REG_BIT_RATE		0x48
+#define SPI_REG_TX_CTRL			0x4c
+#define SPI_REG_TX_DATA			0x50
+#define SPI_REG_RX_CTRL			0x54
+#define SPI_REG_RX_DATA			0x58
+#define SPI_REG_FIFO_TX_CFG		0x5c
+#define SPI_REG_FIFO_TX_CTRL		0x60
+#define SPI_REG_FIFO_RX_CFG		0x64
+#define SPI_REG_INTR_STAT		0x68
+#define SPI_REG_INTR_ENA		0x6c
+
+#define CFG_SPI_EN			BIT(31)
+#define CFG_SPI_CLKPOL			BIT(14)
+#define CFG_SPI_CLKPHA			BIT(13)
+#define CFG_SPI_MASTER_EN		BIT(11)
+#define CFG_SPI_CHAR_LEN_M		0x3
+#define CFG_SPI_CHAR_LEN_8BITS		0
+#define CFG_SPI_CHAR_LEN_16BITS		1
+#define CFG_SPI_CHAR_LEN_24BITS		2
+#define CFG_SPI_CHAR_LEN_32BITS		3
+
+#define STAT_SPI_BUSY_STA		BIT(1)
+
+#define BIT_RATE_DIV_1			0
+#define BIT_RATE_DIV_2			1
+#define BIT_RATE_DIV_4			2
+#define BIT_RATE_DIV_8			3
+#define BIT_RATE_DIV_16			4
+#define BIT_RATE_DIV_32			5
+#define BIT_RATE_DIV_64			6
+#define BIT_RATE_DIV_128		7
+
+#define TX_CTRL_SPI_TXDAT_EOF		BIT(2)
+#define TX_CTRL_SPI_TXCH_NUM_M		0x3
+#define TX_CTRL_CLEAR_MASK		(TX_CTRL_SPI_TXDAT_EOF | \
+					 TX_CTRL_SPI_TXCH_NUM_M)
+
+#define RX_CTRL_SPI_RXDAT_EOF		BIT(2)
+#define RX_CTRL_SPI_RXCH_NUM_M		0x3
+
+#define INTR_STAT_SPI_TXBF_UNRN_FG	BIT(7)
+#define INTR_STAT_SPI_RXBF_OVRN_FG	BIT(6)
+#define INTR_STAT_SPI_TXFF_UNRN_FG	BIT(5)
+#define INTR_STAT_SPI_RXFF_OVRN_FG	BIT(4)
+#define INTR_STAT_SPI_TXBUF_FG		BIT(3)
+#define INTR_STAT_SPI_RXBUF_FG		BIT(2)
+#define INTR_STAT_SPI_TXFF_FG		BIT(1)
+#define INTR_STAT_SPI_RXFF_FG		BIT(0)
+
+#define INTR_STAT_CLEAR_MASK		(INTR_STAT_SPI_TXBF_UNRN_FG | \
+					 INTR_STAT_SPI_RXBF_OVRN_FG | \
+					 INTR_STAT_SPI_TXFF_UNRN_FG | \
+					 INTR_STAT_SPI_RXFF_OVRN_FG)
+
+#define FIFO_TX_CFG_SPI_TXFF_THRED_M	0x3
+#define FIFO_TX_CFG_SPI_TXFF_THRED_S	4
+#define FIFO_TX_CFG_SPI_TXFF_THRED_2	0
+#define FIFO_TX_CFG_SPI_TXFF_THRED_4	1
+#define FIFO_TX_CFG_SPI_TXFF_THRED_6	0
+#define FIFO_TX_CFG_SPI_TXFF_STATUS_M	0xf
+
+#define FIFO_RX_CFG_SPI_RXFF_THRED_M	0x3
+#define FIFO_RX_CFG_SPI_RXFF_THRED_S	4
+#define FIFO_RX_CFG_SPI_RXFF_THRED_2	0
+#define FIFO_RX_CFG_SPI_RXFF_THRED_4	1
+#define FIFO_RX_CFG_SPI_RXFF_THRED_6	0
+#define FIFO_RX_CFG_SPI_RXFF_STATUS_M	0xf
+
+#define CNS21XX_SPI_NUM_BIT_RATES	8
+
+struct cns21xx_spi {
+	struct spi_bitbang	bitbang;
+
+	struct spi_master	*master;
+	struct device		*dev;
+	void __iomem		*base;
+	struct resource		*region;
+
+	unsigned		freq_max;
+	unsigned		freq_min;
+
+};
+
+static inline struct cns21xx_spi *to_hw(struct spi_device *spi)
+{
+	return spi_master_get_devdata(spi->master);
+}
+
+static inline u32 cns21xx_spi_rr(struct cns21xx_spi *hw, unsigned int reg)
+{
+	return __raw_readl(hw->base + reg);
+}
+
+static inline void cns21xx_spi_wr(struct cns21xx_spi *hw, u32 val,
+				  unsigned int reg)
+{
+	__raw_writel(val, hw->base + reg);
+}
+
+#define CNS21XX_SPI_RETRY_COUNT		100
+static inline int cns21xx_spi_wait(struct cns21xx_spi *hw, unsigned int reg,
+				   u32 mask, u32 val)
+{
+	int retry_cnt = 0;
+
+	do {
+		if ((cns21xx_spi_rr(hw, reg) & mask) == val)
+			break;
+
+		if (++retry_cnt > CNS21XX_SPI_RETRY_COUNT) {
+			dev_err(hw->dev, "timeout waiting on register %02x\n",
+				reg);
+			return -EIO;
+		}
+	} while (1);
+
+	return 0;
+}
+
+static int cns21xx_spi_txrx_word(struct cns21xx_spi *hw, u8 tx_channel,
+				 u8 tx_eof_flag, u32 tx_data, u32 *rx_data)
+{
+	unsigned int tx_ctrl;
+	u8 rx_channel;
+	u8 rx_eof_flag;
+	int err = 0;
+
+	err = cns21xx_spi_wait(hw, SPI_REG_STAT, STAT_SPI_BUSY_STA, 0);
+	if (err)
+		return err;
+
+	err = cns21xx_spi_wait(hw, SPI_REG_INTR_STAT, INTR_STAT_SPI_TXBUF_FG,
+			       INTR_STAT_SPI_TXBUF_FG);
+	if (err)
+		return err;
+
+	tx_ctrl = cns21xx_spi_rr(hw, SPI_REG_TX_CTRL);
+	tx_ctrl &= ~(TX_CTRL_CLEAR_MASK);
+	tx_ctrl |= (tx_channel & TX_CTRL_SPI_TXCH_NUM_M);
+	tx_ctrl |= (tx_eof_flag) ? TX_CTRL_SPI_TXDAT_EOF : 0;
+	cns21xx_spi_wr(hw, tx_ctrl, SPI_REG_TX_CTRL);
+
+	cns21xx_spi_wr(hw, tx_data, SPI_REG_TX_DATA);
+
+	err = cns21xx_spi_wait(hw, SPI_REG_INTR_STAT, INTR_STAT_SPI_RXBUF_FG,
+			       INTR_STAT_SPI_RXBUF_FG);
+	if (err)
+		return err;
+
+	rx_channel = cns21xx_spi_rr(hw, SPI_REG_RX_CTRL) &
+					RX_CTRL_SPI_RXCH_NUM_M;
+
+	rx_eof_flag = (cns21xx_spi_rr(hw, SPI_REG_RX_CTRL) &
+					RX_CTRL_SPI_RXDAT_EOF) ? 1 : 0;
+
+	*rx_data = cns21xx_spi_rr(hw, SPI_REG_RX_DATA);
+
+	if ((tx_channel != rx_channel) || (tx_eof_flag != rx_eof_flag))
+		return -EPROTO;
+
+	return 0;
+}
+
+static void cns21xx_spi_chipselect(struct spi_device *spi, int value)
+{
+	struct cns21xx_spi *hw = to_hw(spi);
+	unsigned int spi_config;
+	unsigned int tx_ctrl;
+
+	switch (value) {
+	case BITBANG_CS_INACTIVE:
+		break;
+
+	case BITBANG_CS_ACTIVE:
+		spi_config = cns21xx_spi_rr(hw, SPI_REG_CFG);
+
+		if (spi->mode & SPI_CPHA)
+			spi_config |= CFG_SPI_CLKPHA;
+		else
+			spi_config &= ~CFG_SPI_CLKPHA;
+
+		if (spi->mode & SPI_CPOL)
+			spi_config |= CFG_SPI_CLKPOL;
+		else
+			spi_config &= ~CFG_SPI_CLKPOL;
+
+		cns21xx_spi_wr(hw, spi_config, SPI_REG_CFG);
+
+		tx_ctrl = cns21xx_spi_rr(hw, SPI_REG_TX_CTRL);
+		tx_ctrl &= ~(TX_CTRL_CLEAR_MASK);
+		tx_ctrl |= (spi->chip_select & TX_CTRL_SPI_TXCH_NUM_M);
+		cns21xx_spi_wr(hw, tx_ctrl, SPI_REG_TX_CTRL);
+
+		break;
+	}
+}
+
+static int cns21xx_spi_setup(struct spi_device *spi)
+{
+	struct cns21xx_spi *hw = to_hw(spi);
+
+	if (spi->bits_per_word != 8) {
+		dev_err(&spi->dev, "%s: invalid bits_per_word=%u\n",
+			__func__, spi->bits_per_word);
+		return -EINVAL;
+	}
+
+	if (spi->max_speed_hz == 0)
+		spi->max_speed_hz = hw->freq_max;
+
+	if (spi->max_speed_hz > hw->freq_max ||
+	    spi->max_speed_hz < hw->freq_min) {
+		dev_err(&spi->dev, "%s: max_speed_hz=%u out of range\n",
+			__func__, spi->max_speed_hz);
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static int cns21xx_spi_setup_transfer(struct spi_device *spi,
+				      struct spi_transfer *t)
+{
+	struct cns21xx_spi *hw = to_hw(spi);
+	u8	bits_per_word;
+	u32	hz;
+	int	i;
+
+	bits_per_word = (t) ? t->bits_per_word : spi->bits_per_word;
+	hz = t ? t->speed_hz : spi->max_speed_hz;
+
+	if (!bits_per_word)
+		bits_per_word = spi->bits_per_word;
+
+	if (!hz)
+		hz = spi->max_speed_hz;
+
+	if (bits_per_word != 8) {
+		dev_err(&spi->dev, "%s: invalid bits_per_word=%u\n",
+			__func__, bits_per_word);
+		return -EINVAL;
+	}
+
+	if (hz > spi->max_speed_hz || hz > hw->freq_max || hz < hw->freq_min) {
+		dev_err(&spi->dev, "%s: max_speed_hz=%u out of range\n",
+			__func__, hz);
+		return -EINVAL;
+	}
+
+	for (i = 0; i < CNS21XX_SPI_NUM_BIT_RATES; i++)
+		if (spi->max_speed_hz > (cns21xx_get_apb_freq() >> i))
+			break;
+
+	DBG("max_speed:%uHz, curr_speed:%luHz, rate_index=%d\n",
+	    spi->max_speed_hz, cns21xx_get_apb_freq() / (1 << i), i);
+
+	cns21xx_spi_wr(hw, i, SPI_REG_BIT_RATE);
+
+	return 0;
+}
+
+static int cns21xx_spi_txrx(struct spi_device *spi, struct spi_transfer *t)
+{
+	struct cns21xx_spi *hw = to_hw(spi);
+	const unsigned char *tx_buf;
+	unsigned char *rx_buf;
+	u32 rx_data;
+	int tx_eof;
+	int err = 0;
+	int i;
+
+	tx_buf = t->tx_buf;
+	rx_buf = t->rx_buf;
+	tx_eof = t->last_in_message_list;
+
+	DBG("txrx: tx %p, rx %p, len %d\n", tx_buf, rx_buf, t->len);
+
+	if (tx_buf) {
+		for (i = 0; i < t->len; i++)
+			DBG("tx_buf[%02d]: 0x%02x\n", i, tx_buf[i]);
+
+		for (i = 0; i < (t->len - 1); i++) {
+			err = cns21xx_spi_txrx_word(hw, spi->chip_select, 0,
+						    tx_buf[i], &rx_data);
+			if (err)
+				goto done;
+
+			if (rx_buf) {
+				rx_buf[i] = rx_data;
+				DBG("rx_buf[%02d]:0x%02x\n", i, rx_buf[i]);
+			}
+		}
+
+		err = cns21xx_spi_txrx_word(hw, spi->chip_select, tx_eof,
+					    tx_buf[i], &rx_data);
+		if (err)
+			goto done;
+
+		if ((tx_eof) && rx_buf) {
+			rx_buf[i] = rx_data;
+			DBG("rx_buf[%02d]:0x%02x\n", i, rx_buf[i]);
+		}
+	} else if (rx_buf) {
+		for (i = 0; i < (t->len - 1); i++) {
+			err = cns21xx_spi_txrx_word(hw, spi->chip_select, 0,
+						    0xff, &rx_data);
+			if (err)
+				goto done;
+
+			rx_buf[i] = rx_data;
+			DBG("rx_buf[%02d]:0x%02x\n", i, rx_buf[i]);
+		}
+
+		err = cns21xx_spi_txrx_word(hw, spi->chip_select, tx_eof,
+					    0xff, &rx_data);
+		if (err)
+			goto done;
+
+		rx_buf[i] = rx_data;
+		DBG("rx_buf[%02d]:0x%02x\n", i, rx_buf[i]);
+	}
+
+ done:
+	return (err) ? err : t->len;
+}
+
+static void __init cns21xx_spi_hw_init(struct cns21xx_spi *hw)
+{
+	u32 t;
+	u32 pclk;
+
+	/* Setup configuration register */
+	cns21xx_spi_wr(hw, CFG_SPI_MASTER_EN, SPI_REG_CFG);
+
+	/* Set default clock to PCLK/2 */
+	cns21xx_spi_wr(hw, BIT_RATE_DIV_2, SPI_REG_BIT_RATE);
+
+	/* Configure SPI's Tx channel */
+	cns21xx_spi_wr(hw, 0, SPI_REG_TX_CTRL);
+
+	/* Configure Tx FIFO Threshold */
+	t = cns21xx_spi_rr(hw, SPI_REG_FIFO_TX_CFG);
+	t &= ~(FIFO_TX_CFG_SPI_TXFF_THRED_M << FIFO_TX_CFG_SPI_TXFF_THRED_S);
+	t |= (FIFO_TX_CFG_SPI_TXFF_THRED_2 << FIFO_TX_CFG_SPI_TXFF_THRED_S);
+	cns21xx_spi_wr(hw, t, SPI_REG_FIFO_TX_CFG);
+
+	/* Configure Rx FIFO Threshold */
+	t = cns21xx_spi_rr(hw, SPI_REG_FIFO_RX_CFG);
+	t &= ~(FIFO_RX_CFG_SPI_RXFF_THRED_M << FIFO_RX_CFG_SPI_RXFF_THRED_S);
+	t |= (FIFO_RX_CFG_SPI_RXFF_THRED_2 << FIFO_RX_CFG_SPI_RXFF_THRED_S);
+	cns21xx_spi_wr(hw, t, SPI_REG_FIFO_RX_CFG);
+
+	/* Disable interrupts, and clear interrupt status */
+	cns21xx_spi_wr(hw, 0, SPI_REG_INTR_ENA);
+	cns21xx_spi_wr(hw, INTR_STAT_CLEAR_MASK, SPI_REG_INTR_STAT);
+
+	(void) cns21xx_spi_rr(hw, SPI_REG_RX_DATA);
+
+	/* Enable SPI */
+	t = cns21xx_spi_rr(hw, SPI_REG_CFG);
+	t |= CFG_SPI_EN;
+	cns21xx_spi_wr(hw, t, SPI_REG_CFG);
+
+	pclk = cns21xx_get_apb_freq();
+	hw->freq_max = pclk;
+	hw->freq_min = pclk / (1 << BIT_RATE_DIV_128);
+}
+
+static int __init cns21xx_spi_probe(struct platform_device *pdev)
+{
+	struct cns21xx_spi *hw;
+	struct spi_master *master;
+	struct resource *res;
+	int err = 0;
+
+	master = spi_alloc_master(&pdev->dev, sizeof(struct cns21xx_spi));
+	if (!master) {
+		dev_err(&pdev->dev, "No memory for spi_master\n");
+		return -ENOMEM;
+	}
+
+	hw = spi_master_get_devdata(master);
+
+	platform_set_drvdata(pdev, hw);
+	hw->master = spi_master_get(master);
+	hw->dev = &pdev->dev;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res) {
+		dev_dbg(&pdev->dev, "no MEM resource found\n");
+		err = -ENOENT;
+		goto err_put_master;
+	}
+
+	hw->region = request_mem_region(res->start, resource_size(res),
+					dev_name(&pdev->dev));
+	if (!hw->region) {
+		dev_err(&pdev->dev, "unable to reserve iomem region\n");
+		err = -ENXIO;
+		goto err_put_master;
+	}
+
+	hw->base = ioremap(res->start, resource_size(res));
+	if (!hw->base) {
+		dev_err(&pdev->dev, "ioremap failed\n");
+		err = -ENOENT;
+		goto err_release_region;
+	}
+
+	cns21xx_spi_hw_init(hw);
+
+	master->bus_num = pdev->id;
+	if (master->bus_num == -1)
+		master->bus_num = 0;
+
+	master->num_chipselect = 4;
+	master->setup = cns21xx_spi_setup;
+
+	hw->bitbang.master = hw->master;
+	hw->bitbang.chipselect = cns21xx_spi_chipselect;
+	hw->bitbang.txrx_bufs = cns21xx_spi_txrx;
+	hw->bitbang.setup_transfer = cns21xx_spi_setup_transfer;
+
+	err = spi_bitbang_start(&hw->bitbang);
+	if (err) {
+		dev_err(hw->dev, "unable to register SPI master\n");
+		goto err_unmap;
+	}
+
+	dev_info(hw->dev, "iomem at %08x\n", res->start);
+
+	return 0;
+
+ err_unmap:
+	iounmap(hw->base);
+
+ err_release_region:
+	release_resource(hw->region);
+	kfree(hw->region);
+
+ err_put_master:
+	spi_master_put(hw->bitbang.master);
+	platform_set_drvdata(pdev, NULL);
+
+	return err;
+}
+
+static int __devexit cns21xx_spi_remove(struct platform_device *pdev)
+{
+	struct cns21xx_spi *hw = platform_get_drvdata(pdev);
+
+	spi_bitbang_stop(&hw->bitbang);
+	iounmap(hw->base);
+	release_resource(hw->region);
+	kfree(hw->region);
+	spi_master_put(hw->bitbang.master);
+	platform_set_drvdata(pdev, NULL);
+
+	return 0;
+}
+
+static struct platform_driver cns21xx_spi_driver = {
+	.remove		= __devexit_p(cns21xx_spi_remove),
+	.driver		= {
+		.name	= DRIVER_NAME,
+		.owner	= THIS_MODULE,
+	},
+};
+
+static int __init cns21xx_spi_init(void)
+{
+	return platform_driver_probe(&cns21xx_spi_driver, cns21xx_spi_probe);
+}
+
+static void __exit cns21xx_spi_exit(void)
+{
+	platform_driver_unregister(&cns21xx_spi_driver);
+}
+
+module_init(cns21xx_spi_init);
+module_exit(cns21xx_spi_exit);
+
+MODULE_DESCRIPTION("Cavium Networks CNS21xx SPI Controller driver");
+MODULE_AUTHOR("STAR Semi Corp.");
+MODULE_AUTHOR("Gabor Juhos <juhosg@openwrt.org>");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:" DRIVER_NAME);