path: root/patches/linux-3.11-rc1/0003-spi-new-controller-driver-for-efm32-SoCs.patch

From: =?UTF-8?q?Uwe=20Kleine-K=C3=B6nig?= <u.kleine-koenig@pengutronix.de>
Date: Thu, 23 Feb 2012 10:44:35 +0100
Subject: [PATCH] spi: new controller driver for efm32 SoCs
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
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known issues:
	efm32-spi efm32-spi.1: master is unqueued, this is deprecated

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
---
 drivers/spi/Kconfig     |   5 +
 drivers/spi/Makefile    |   1 +
 drivers/spi/spi-efm32.c | 481 ++++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 487 insertions(+)
 create mode 100644 drivers/spi/spi-efm32.c

diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig
index 89cbbab..6a273d3 100644
--- a/drivers/spi/Kconfig
+++ b/drivers/spi/Kconfig
@@ -157,6 +157,11 @@ config SPI_DAVINCI
 	help
 	  SPI master controller for DaVinci/DA8x/OMAP-L/AM1x SPI modules.
 
+config SPI_EFM32
+	tristate "EFM32 SPI controller"
+	depends on ARCH_EFM32
+	select SPI_BITBANG
+
 config SPI_EP93XX
 	tristate "Cirrus Logic EP93xx SPI controller"
 	depends on ARCH_EP93XX
diff --git a/drivers/spi/Makefile b/drivers/spi/Makefile
index 33f9c09..4a1cfb2 100644
--- a/drivers/spi/Makefile
+++ b/drivers/spi/Makefile
@@ -27,6 +27,7 @@ obj-$(CONFIG_SPI_DESIGNWARE)		+= spi-dw.o
 obj-$(CONFIG_SPI_DW_MMIO)		+= spi-dw-mmio.o
 obj-$(CONFIG_SPI_DW_PCI)		+= spi-dw-midpci.o
 spi-dw-midpci-objs			:= spi-dw-pci.o spi-dw-mid.o
+obj-$(CONFIG_SPI_EFM32)			+= spi-efm32.o
 obj-$(CONFIG_SPI_EP93XX)		+= spi-ep93xx.o
 obj-$(CONFIG_SPI_FALCON)		+= spi-falcon.o
 obj-$(CONFIG_SPI_FSL_CPM)		+= spi-fsl-cpm.o
diff --git a/drivers/spi/spi-efm32.c b/drivers/spi/spi-efm32.c
new file mode 100644
index 0000000..f20b36b
--- /dev/null
+++ b/drivers/spi/spi-efm32.c
@@ -0,0 +1,481 @@
+/*
+ * Copyright (C) 2012 Uwe Kleine-Koenig for Pengutronix
+ *
+ * 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/io.h>
+#include <linux/spi/spi.h>
+#include <linux/spi/spi_bitbang.h>
+#include <linux/gpio.h>
+#include <linux/interrupt.h>
+#include <linux/platform_device.h>
+#include <linux/clk.h>
+#include <linux/err.h>
+#include <linux/module.h>
+#include <linux/of_gpio.h>
+
+#define DRIVER_NAME "efm32-spi"
+
+#define REG_CTRL		0x00
+#define REG_CTRL_SYNC			0x0001
+#define REG_CTRL_CLKPOL			0x0100
+#define REG_CTRL_CLKPHA			0x0200
+#define REG_CTRL_MSBF			0x0400
+#define REG_CTRL_TXBIL			0x1000
+
+#define REG_FRAME		0x04
+#define REG_FRAME_DATABITS__MASK	0x000f
+#define REG_FRAME_DATABITS(n)		((n) - 3)
+
+#define REG_CMD			0x0c
+#define REG_CMD_RXEN			0x0001
+#define REG_CMD_RXDIS			0x0002
+#define REG_CMD_TXEN			0x0004
+#define REG_CMD_TXDIS			0x0008
+#define REG_CMD_MASTEREN		0x0010
+
+#define REG_STATUS		0x10
+#define REG_STATUS_TXENS		0x0002
+#define REG_STATUS_TXC			0x0020
+#define REG_STATUS_TXBL			0x0040
+#define REG_STATUS_RXDATAV		0x0080
+
+#define REG_CLKDIV		0x14
+
+#define REG_RXDATAX		0x18
+#define REG_RXDATAX_RXDATA__MASK	0x01ff
+#define REG_RXDATAX_PERR		0x4000
+#define REG_RXDATAX_FERR		0x8000
+
+#define REG_TXDATA		0x34
+
+#define REG_IF		0x40
+#define REG_IF_TXBL			0x0002
+#define REG_IF_RXDATAV			0x0004
+
+#define REG_IFS		0x44
+#define REG_IFC		0x48
+#define REG_IEN		0x4c
+
+#define REG_ROUTE		0x54
+#define REG_ROUTE_RXPEN			0x0001
+#define REG_ROUTE_TXPEN			0x0002
+#define REG_ROUTE_CLKPEN		0x0008
+#define REG_ROUTE_LOCATION__MASK	0x0700
+#define REG_ROUTE_LOCATION(n)		(((n) << 8) & REG_ROUTE_LOCATION__MASK)
+
+struct efm32_spi_ddata {
+	/* bitbang must be the first member */
+	struct spi_bitbang bitbang;
+
+	spinlock_t lock;
+
+	struct clk *clk;
+	void __iomem *base;
+	unsigned int rxirq, txirq;
+
+	/* irq data */
+	struct completion done;
+	const void *tx_buf;
+	void *rx_buf;
+	unsigned tx_len, rx_len;
+	unsigned csgpio[];
+};
+
+static void efm32_spi_write32(struct efm32_spi_ddata *ddata,
+		u32 value, unsigned offset)
+{
+	writel_relaxed(value, ddata->base + offset);
+}
+
+static u32 efm32_spi_read32(struct efm32_spi_ddata *ddata, unsigned offset)
+{
+	return readl_relaxed(ddata->base + offset);
+}
+
+static int efm32_spi_setup(struct spi_device *spi)
+{
+	pr_debug("%s\n", __func__);
+
+	return 0;
+
+}
+
+static void efm32_spi_cleanup(struct spi_device *spi)
+{
+	pr_debug("%s\n", __func__);
+}
+
+static void efm32_spi_chipselect(struct spi_device *spi, int is_on)
+{
+	struct efm32_spi_ddata *ddata = spi_master_get_devdata(spi->master);
+	int value = !(spi->mode & SPI_CS_HIGH) == !(is_on == BITBANG_CS_ACTIVE);
+
+	gpio_set_value(ddata->csgpio[spi->chip_select], value);
+}
+
+static int efm32_spi_setup_transfer(struct spi_device *spi, struct spi_transfer *t)
+{
+	struct efm32_spi_ddata *ddata = spi_master_get_devdata(spi->master);
+
+	unsigned bpw = t && t->bits_per_word ?
+		t->bits_per_word : spi->bits_per_word;
+	unsigned speed = t && t->speed_hz ? t->speed_hz : spi->max_speed_hz;
+	unsigned long clkfreq = clk_get_rate(ddata->clk);
+	u32 clkdiv;
+
+	efm32_spi_write32(ddata, REG_CTRL_SYNC | REG_CTRL_MSBF |
+			(spi->mode & SPI_CPHA ? REG_CTRL_CLKPHA : 0) |
+			(spi->mode & SPI_CPOL ? REG_CTRL_CLKPOL : 0), REG_CTRL);
+
+	efm32_spi_write32(ddata,
+			REG_FRAME_DATABITS(bpw), REG_FRAME);
+	/* XXX */
+	if (2 * speed >= clkfreq)
+		clkdiv = 0;
+	else
+		clkdiv = 64 * (DIV_ROUND_UP(2 * clkfreq, speed) - 4);
+
+	if (clkdiv > (1U << 21))
+		return -EINVAL;
+
+	efm32_spi_write32(ddata, clkdiv, REG_CLKDIV);
+	efm32_spi_write32(ddata, REG_CMD_MASTEREN, REG_CMD);
+	efm32_spi_write32(ddata, REG_CMD_RXEN | REG_CMD_TXEN, REG_CMD);
+
+	return 0;
+}
+
+#define DEFINE_EFM32_SPI_XFER(type)					\
+static void efm32_spi_tx_ ## type(struct efm32_spi_ddata *ddata)	\
+{									\
+	type val = 0;							\
+									\
+	if (ddata->tx_len >= sizeof(type)) {				\
+		if (ddata->tx_buf) {					\
+			val = *(type *)ddata->tx_buf;			\
+			ddata->tx_buf += sizeof(type);			\
+		}							\
+									\
+		ddata->tx_len -= sizeof(type);				\
+		efm32_spi_write32(ddata, val, REG_TXDATA);		\
+		pr_debug("%s: tx 0x%x\n", __func__, val);		\
+	}								\
+}									\
+									\
+static void efm32_spi_rx_ ## type(struct efm32_spi_ddata *ddata)	\
+{									\
+	if (ddata->rx_len >= sizeof(type)) {				\
+		u32 rxdata = efm32_spi_read32(ddata, REG_RXDATAX);	\
+		pr_debug("%s: rx 0x%x\n", __func__, rxdata);		\
+									\
+		if (ddata->rx_buf) {					\
+			*(type *)ddata->rx_buf = rxdata;		\
+			ddata->rx_buf += sizeof(type);			\
+		}							\
+									\
+		ddata->rx_len -= sizeof(type);				\
+	}								\
+}
+
+DEFINE_EFM32_SPI_XFER(u8)
+
+static void efm32_spi_filltx(struct efm32_spi_ddata *ddata)
+{
+	while (ddata->tx_len &&
+			ddata->tx_len + 2 /* XXX * bpw */ > ddata->rx_len &&
+			efm32_spi_read32(ddata, REG_STATUS) & REG_STATUS_TXBL) {
+		efm32_spi_tx_u8(ddata);
+	}
+}
+
+static int efm32_spi_txrx_bufs(struct spi_device *spi, struct spi_transfer *t)
+{
+	struct efm32_spi_ddata *ddata = spi_master_get_devdata(spi->master);
+	int ret = -EBUSY;
+
+	spin_lock_irq(&ddata->lock);
+
+	if (ddata->tx_buf || ddata->rx_buf)
+		goto out_unlock;
+
+	ddata->tx_buf = t->tx_buf;
+	ddata->rx_buf = t->rx_buf;
+	ddata->tx_len = ddata->rx_len = t->len;
+
+	efm32_spi_filltx(ddata);
+
+	init_completion(&ddata->done);
+
+	efm32_spi_write32(ddata, REG_IF_TXBL | REG_IF_RXDATAV, REG_IEN);
+
+	spin_unlock_irq(&ddata->lock);
+
+	wait_for_completion(&ddata->done);
+
+	spin_lock_irq(&ddata->lock);
+
+	ret = t->len - max(ddata->tx_len, ddata->rx_len);
+
+	efm32_spi_write32(ddata, 0, REG_IEN);
+	ddata->tx_buf = ddata->rx_buf = NULL;
+
+out_unlock:
+	spin_unlock_irq(&ddata->lock);
+
+	return ret;
+}
+
+static irqreturn_t efm32_spi_rxirq(int irq, void *data)
+{
+	struct efm32_spi_ddata *ddata = data;
+	irqreturn_t ret = IRQ_NONE;
+
+	spin_lock(&ddata->lock);
+
+	while (ddata->rx_len > 0 &&
+			efm32_spi_read32(ddata, REG_STATUS) &
+			REG_STATUS_RXDATAV) {
+		efm32_spi_rx_u8(ddata);
+
+		ret = IRQ_HANDLED;
+	}
+
+	if (!ddata->rx_len) {
+		u32 ien = efm32_spi_read32(ddata, REG_IEN);
+
+		ien &= ~REG_IF_RXDATAV;
+
+		efm32_spi_write32(ddata, ien, REG_IEN);
+
+		complete(&ddata->done);
+	}
+
+	spin_unlock(&ddata->lock);
+
+	return ret;
+}
+
+static irqreturn_t efm32_spi_txirq(int irq, void *data)
+{
+	struct efm32_spi_ddata *ddata = data;
+
+	pr_debug("%s: txlen = %u, rxlen = %u, if=0x%08x, status=0x%08x\n",
+			__func__, ddata->tx_len, ddata->rx_len,
+			efm32_spi_read32(ddata, REG_IF),
+			efm32_spi_read32(ddata, REG_STATUS));
+
+	spin_lock(&ddata->lock);
+
+	efm32_spi_filltx(ddata);
+
+	pr_debug("%s: txlen = %u, rxlen = %u\n", __func__,
+			ddata->tx_len, ddata->rx_len);
+
+	if (!ddata->tx_len) {
+		u32 ien = efm32_spi_read32(ddata, REG_IEN);
+
+		ien &= ~REG_IF_TXBL;
+
+		efm32_spi_write32(ddata, ien, REG_IEN);
+		pr_debug("disable TXBL\n");
+	}
+
+	spin_unlock(&ddata->lock);
+
+	return IRQ_HANDLED;
+}
+
+static int efm32_spi_probe(struct platform_device *pdev)
+{
+	struct efm32_spi_ddata *ddata;
+	struct resource *res;
+	int ret;
+	struct spi_master *master;
+	struct device_node *np = pdev->dev.of_node;
+	unsigned int num_cs, i;
+
+	num_cs = of_gpio_named_count(np, "cs-gpios");
+
+	master = spi_alloc_master(&pdev->dev,
+			sizeof(*ddata) + num_cs * sizeof(unsigned));
+	if (!master) {
+		dev_dbg(&pdev->dev,
+				"failed to allocate spi master controller\n");
+		return -ENOMEM;
+	}
+	platform_set_drvdata(pdev, master);
+
+	master->dev.of_node = pdev->dev.of_node;
+
+	master->bus_num = pdev->id;
+	master->num_chipselect = num_cs;
+	master->setup = efm32_spi_setup;
+	master->cleanup = efm32_spi_cleanup;
+	master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH;
+
+	ddata = spi_master_get_devdata(master);
+
+	ddata->bitbang.master = spi_master_get(master);
+	ddata->bitbang.chipselect = efm32_spi_chipselect;
+	ddata->bitbang.setup_transfer = efm32_spi_setup_transfer;
+	ddata->bitbang.txrx_bufs = efm32_spi_txrx_bufs;
+
+	spin_lock_init(&ddata->lock);
+
+	ddata->clk = clk_get(&pdev->dev, NULL);
+	if (IS_ERR(ddata->clk)) {
+		ret = PTR_ERR(ddata->clk);
+		dev_dbg(&pdev->dev, "failed to get clock: %d\n", ret);
+		goto err_clk_get;
+	}
+
+	for (i = 0; i < num_cs; ++i) {
+		ret = of_get_named_gpio(np, "cs-gpios", i);
+		if (ret < 0) {
+			dev_err(&pdev->dev, "failed to get csgpio#%u (%d)\n",
+					i, ret);
+			//goto err_get_csgpio;
+		}
+		ddata->csgpio[i] = ret;
+		dev_dbg(&pdev->dev, "csgpio#%u = %u\n", i, ddata->csgpio[i]);
+		ret = gpio_request_one(ddata->csgpio[i],
+				GPIOF_OUT_INIT_LOW, DRIVER_NAME);
+		if (ret < 0) {
+			dev_err(&pdev->dev,
+					"failed to configure csgpio#%u (%d)\n",
+					i, ret);
+			//goto err_csgpio_request;
+		}
+	}
+
+	/* XXX: enable only on demand */
+	ret = clk_prepare_enable(ddata->clk);
+	if (ret < 0) {
+		dev_dbg(&pdev->dev, "failed to enable clock: %d\n", ret);
+		goto err_clk_enable;
+	}
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res) {
+		ret = -ENODEV;
+		dev_dbg(&pdev->dev, "failed to determine base address\n");
+		goto err_get_base;
+	}
+
+	if (resource_size(res) < 60) {
+		ret = -EINVAL;
+		dev_dbg(&pdev->dev, "memory resource too small\n");
+		goto err_too_small;
+	}
+
+	/* XXX: request_mem_region? */
+
+	ddata->base = ioremap(res->start, resource_size(res));
+	if (!ddata->base) {
+		ret = -ENOMEM;
+		dev_dbg(&pdev->dev, "failed to remap memory\n");
+		goto err_ioremap;
+	}
+
+	ret = platform_get_irq(pdev, 0);
+	if (ret <= 0) {
+		dev_dbg(&pdev->dev, "failed to get rx irq\n");
+		goto err_get_rxirq;
+	}
+
+	ddata->rxirq = ret;
+
+	ret = platform_get_irq(pdev, 1);
+	if (ret <= 0)
+		ret = ddata->rxirq + 1;
+
+	ddata->txirq = ret;
+
+	efm32_spi_write32(ddata, 0, REG_IEN);
+	efm32_spi_write32(ddata, REG_ROUTE_TXPEN | REG_ROUTE_RXPEN |
+			REG_ROUTE_CLKPEN | REG_ROUTE_LOCATION(1), REG_ROUTE);
+
+	ret = request_irq(ddata->rxirq, efm32_spi_rxirq, 0, DRIVER_NAME, ddata);
+	if (ret) {
+		dev_dbg(&pdev->dev, "failed to register rxirq (%d)\n", ret);
+		goto err_request_rxirq;
+	}
+
+	ret = request_irq(ddata->txirq, efm32_spi_txirq, 0, DRIVER_NAME, ddata);
+	if (ret) {
+		dev_dbg(&pdev->dev, "failed to register txirq (%d)\n", ret);
+		goto err_request_txirq;
+	}
+
+	ret = spi_bitbang_start(&ddata->bitbang);
+	if (ret) {
+		dev_dbg(&pdev->dev, "spi_bitbang_start failed: %d\n", ret);
+
+		free_irq(ddata->txirq, ddata);
+err_request_txirq:
+
+		free_irq(ddata->rxirq, ddata);
+err_request_rxirq:
+err_get_rxirq:
+		iounmap(ddata->base);
+err_ioremap:
+err_too_small:
+err_get_base:
+		clk_disable_unprepare(ddata->clk);
+err_clk_enable:
+		clk_put(ddata->clk);
+err_clk_get:
+		platform_set_drvdata(pdev, NULL);
+		spi_master_put(master);
+		kfree(master);
+	}
+
+	pr_debug("%s returns %d\n", __func__, ret);
+	return ret;
+}
+
+static int efm32_spi_remove(struct platform_device *pdev)
+{
+	struct spi_master *master = platform_get_drvdata(pdev);
+	struct efm32_spi_ddata *ddata = spi_master_get_devdata(master);
+
+	free_irq(ddata->txirq, ddata);
+	free_irq(ddata->rxirq, ddata);
+	iounmap(ddata->base);
+	clk_put(ddata->clk);
+	platform_set_drvdata(pdev, NULL);
+	spi_master_put(master);
+	kfree(master);
+
+	return 0;
+}
+
+static const struct of_device_id efm32_spi_dt_ids[] = {
+	{
+		.compatible = "efm32,spi",
+	}, {
+		/* sentinel */
+	}
+};
+MODULE_DEVICE_TABLE(of, efm32_uart_dt_ids);
+
+static struct platform_driver efm32_spi_driver = {
+	.probe = efm32_spi_probe,
+	.remove = efm32_spi_remove,
+
+	.driver = {
+		.name = DRIVER_NAME,
+		.owner = THIS_MODULE,
+		.of_match_table = efm32_spi_dt_ids,
+	},
+};
+module_platform_driver(efm32_spi_driver);
+
+MODULE_AUTHOR("Uwe Kleine-Koenig <u.kleine-koenig@pengutronix.de>");
+MODULE_DESCRIPTION("EFM32 SPI driver");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:" DRIVER_NAME);