spi: driver for Cirrus EP93xx SPI controller

new file mode 100644
index 0000000..0a37961
@@ -0,0 +1,27 @@
+#ifndef __ASM_MACH_EP93XX_SPI_H
+#define __ASM_MACH_EP93XX_SPI_H
+
+struct spi_device;
+
+/**
+ * struct ep93xx_spi_info - EP93xx specific SPI descriptor
+ * @num_chipselect: number of chip selects on this board, must be
+ *                  at least one
+ */
+struct ep93xx_spi_info {
+	int	num_chipselect;
+};
+
+/**
+ * struct ep93xx_spi_chip_ops - operation callbacks for SPI slave device
+ * @setup: setup the chip select mechanism
+ * @cleanup: cleanup the chip select mechanism
+ * @cs_control: control the device chip select
+ */
+struct ep93xx_spi_chip_ops {
+	int	(*setup)(struct spi_device *spi);
+	void	(*cleanup)(struct spi_device *spi);
+	void	(*cs_control)(struct spi_device *spi, int value);
+};
+
+#endif /* __ASM_MACH_EP93XX_SPI_H */

938 lines not on this page · raw message

index cd93990..b102150 100644
@@ -18,13 +18,17 @@
 #include <linux/kernel.h>
 #include <linux/init.h>
 #include <linux/platform_device.h>
+#include <linux/mmc/host.h>
 #include <linux/mtd/physmap.h>
 #include <linux/gpio.h>
+#include <linux/spi/spi.h>
+#include <linux/spi/mmc_spi.h>
 #include <linux/i2c.h>
 #include <linux/i2c-gpio.h>
 
 #include <mach/hardware.h>
 #include <mach/fb.h>
+#include <mach/ep93xx_spi.h>
 
 #include <asm/mach-types.h>
 #include <asm/mach/arch.h>

@@ -59,6 +63,126 @@ static struct ep93xxfb_mach_info simone_fb_info = {
 	.flags		= EP93XXFB_USE_SDCSN0 | EP93XXFB_PCLK_FALLING,
 };
 
+/*
+ * GPIO lines used for MMC chip select and card detection.
+ */
+#define MMC_CARD_DETECT_GPIO EP93XX_GPIO_LINE_EGPIO0
+#define MMC_CHIP_SELECT_GPIO EP93XX_GPIO_LINE_EGPIO9
+
+/*
+ * MMC SPI chip select GPIO handling. If you are using SFRMOUT (SFRM1) signal,
+ * you can leave these empty and pass NULL as .controller_data.
+ */
+
+static int simone_mmc_spi_setup(struct spi_device *spi)
+{
+	unsigned int gpio = MMC_CHIP_SELECT_GPIO;
+	int err;
+
+	err = gpio_request(gpio, spi->modalias);
+	if (err)
+		return err;
+
+	err = gpio_direction_output(gpio, 1);
+	if (err) {
+		gpio_free(gpio);
+		return err;
+	}
+
+	return 0;
+}
+
+static void simone_mmc_spi_cleanup(struct spi_device *spi)
+{
+	unsigned int gpio = MMC_CHIP_SELECT_GPIO;
+
+	gpio_set_value(gpio, 1);
+	gpio_direction_input(gpio);
+	gpio_free(gpio);
+}
+
+static void simone_mmc_spi_cs_control(struct spi_device *spi, int value)
+{
+	gpio_set_value(MMC_CHIP_SELECT_GPIO, value);
+}
+
+static struct ep93xx_spi_chip_ops simone_mmc_spi_ops = {
+	.setup		= simone_mmc_spi_setup,
+	.cleanup	= simone_mmc_spi_cleanup,
+	.cs_control	= simone_mmc_spi_cs_control,
+};
+
+/*
+ * MMC card detection GPIO setup.
+ */
+
+static int simone_mmc_spi_init(struct device *dev,
+	irqreturn_t (*irq_handler)(int, void *), void *mmc)
+{
+	unsigned int gpio = MMC_CARD_DETECT_GPIO;
+	int irq, err;
+
+	err = gpio_request(gpio, dev_name(dev));
+	if (err)
+		return err;
+
+	err = gpio_direction_input(gpio);
+	if (err)
+		goto fail;
+
+	irq = gpio_to_irq(gpio);
+	if (irq < 0)
+		goto fail;
+
+	err = request_irq(irq, irq_handler, IRQF_TRIGGER_FALLING,
+			  "MMC card detect", mmc);
+	if (err)
+		goto fail;
+
+	printk(KERN_INFO "%s: using irq %d for MMC card detection\n",
+	       dev_name(dev), irq);
+
+	return 0;
+fail:
+	gpio_free(gpio);
+	return err;
+}
+
+static void simone_mmc_spi_exit(struct device *dev, void *mmc)
+{
+	unsigned int gpio = MMC_CARD_DETECT_GPIO;
+
+	free_irq(gpio_to_irq(gpio), mmc);
+	gpio_free(gpio);
+}
+
+static struct mmc_spi_platform_data simone_mmc_spi_data = {
+	.init		= simone_mmc_spi_init,
+	.exit		= simone_mmc_spi_exit,
+	.detect_delay	= 500,
+	.ocr_mask	= MMC_VDD_32_33 | MMC_VDD_33_34,
+};
+
+static struct spi_board_info simone_spi_devices[] __initdata = {
+	{
+		.modalias		= "mmc_spi",
+		.controller_data	= &simone_mmc_spi_ops,
+		.platform_data		= &simone_mmc_spi_data,
+		/*
+		 * We use 10 MHz even though the maximum is 3.7 MHz. The driver
+		 * will limit it automatically to max. frequency.
+		 */
+		.max_speed_hz		= 10 * 1000 * 1000,
+		.bus_num		= 0,
+		.chip_select		= 0,
+		.mode			= SPI_MODE_0,
+	},
+};
+
+static struct ep93xx_spi_info simone_spi_info __initdata = {
+	.num_chipselect	= ARRAY_SIZE(simone_spi_devices),
+};
+
 static struct i2c_gpio_platform_data simone_i2c_gpio_data = {
 	.sda_pin		= EP93XX_GPIO_LINE_EEDAT,
 	.sda_is_open_drain	= 0,

@@ -83,6 +207,8 @@ static void __init simone_init_machine(void)
 	ep93xx_register_fb(&simone_fb_info);
 	ep93xx_register_i2c(&simone_i2c_gpio_data, simone_i2c_board_info,
 			    ARRAY_SIZE(simone_i2c_board_info));
+	ep93xx_register_spi(&simone_spi_info, simone_spi_devices,
+			    ARRAY_SIZE(simone_spi_devices));
 }
 
 MACHINE_START(SIM_ONE, "Simplemachines Sim.One Board")

index 5f80092..e29bdef 100644
@@ -96,6 +96,10 @@ static struct clk clk_keypad = {
 	.enable_mask	= EP93XX_SYSCON_KEYTCHCLKDIV_KEN,
 	.set_rate	= set_keytchclk_rate,
 };
+static struct clk clk_spi = {
+	.parent		= &clk_xtali,
+	.rate		= EP93XX_EXT_CLK_RATE,
+};
 static struct clk clk_pwm = {
 	.parent		= &clk_xtali,
 	.rate		= EP93XX_EXT_CLK_RATE,

@@ -186,6 +190,7 @@ static struct clk_lookup clocks[] = {
 	INIT_CK("ep93xx-ohci",		NULL,		&clk_usb_host),
 	INIT_CK("ep93xx-keypad",	NULL,		&clk_keypad),
 	INIT_CK("ep93xx-fb",		NULL,		&clk_video),
+	INIT_CK("ep93xx-spi.0",		NULL,		&clk_spi),
 	INIT_CK(NULL,			"pwm_clk",	&clk_pwm),
 	INIT_CK(NULL,			"m2p0",		&clk_m2p0),
 	INIT_CK(NULL,			"m2p1",		&clk_m2p1),

@@ -473,6 +478,14 @@ static int __init ep93xx_clock_init(void)
 	/* Initialize the pll2 derived clocks */
 	clk_usb_host.rate = clk_pll2.rate / (((value >> 28) & 0xf) + 1);
 
+	/*
+	 * EP93xx SSP clock rate was doubled in version E2. For more information
+	 * see:
+	 *     http://www.cirrus.com/en/pubs/appNote/AN273REV4.pdf
+	 */
+	if (ep93xx_chip_revision() < EP93XX_CHIP_REV_E2)
+		clk_spi.rate /= 2;
+
 	pr_info("PLL1 running at %ld MHz, PLL2@%ld MHz\n",
 		clk_pll1.rate / 1000000, clk_pll2.rate / 1000000);
 	pr_info("FCLK %ld MHz, HCLK %ld MHz, PCLK %ld MHz\n",

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index 93e2ecc..b1e096f 100644
@@ -106,6 +106,7 @@
 
 #define EP93XX_AAC_BASE			EP93XX_APB_IOMEM(0x00080000)
 
+#define EP93XX_SPI_PHYS_BASE		EP93XX_APB_PHYS(0x000a0000)
 #define EP93XX_SPI_BASE			EP93XX_APB_IOMEM(0x000a0000)
 
 #define EP93XX_IRDA_BASE		EP93XX_APB_IOMEM(0x000b0000)

index c6dc14d..f11f1d7 100644
@@ -6,9 +6,11 @@
 
 struct i2c_gpio_platform_data;
 struct i2c_board_info;
+struct spi_board_info;
 struct platform_device;
 struct ep93xxfb_mach_info;
 struct ep93xx_keypad_platform_data;
+struct ep93xx_spi_info;
 
 struct ep93xx_eth_data
 {

@@ -36,6 +38,8 @@ static inline void ep93xx_devcfg_clear_bits(unsigned int bits)
 void ep93xx_register_eth(struct ep93xx_eth_data *data, int copy_addr);
 void ep93xx_register_i2c(struct i2c_gpio_platform_data *data,
 			 struct i2c_board_info *devices, int num);
+void ep93xx_register_spi(struct ep93xx_spi_info *info,
+			 struct spi_board_info *devices, int num);
 void ep93xx_register_fb(struct ep93xxfb_mach_info *data);
 void ep93xx_register_pwm(int pwm0, int pwm1);
 int ep93xx_pwm_acquire_gpio(struct platform_device *pdev);