ARM: 6124/1: ep93xx: SPI driver platform support code

This patch adds platform side support code for the EP93xx SPI
driver. This includes clock, resources and muxing. There is a new
function: ep93xx_register_spi() which can be used by board support
code to register new SPI devices for the board.

This patch depends on patch
  5998/1 ep93xx: added chip revision reading function

Cc: Ryan Mallon <ryan@bluewatersys.com>
Cc: David Brownell <dbrownell@users.sourceforge.net>
Cc: Grant Likely <grant.likely@secretlab.ca>
Signed-off-by: Mika Westerberg <mika.westerberg@iki.fi>
Acked-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Acked-by: Martin Guy <martinwguy@gmail.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

4 files changed, 70 insertions, 0 deletions

diff --git a/arch/arm/mach-ep93xx/clock.c b/arch/arm/mach-ep93xx/clock.c
index 5f80092b6ac..e29bdef9b2e 100644
--- a/arch/arm/mach-ep93xx/clock.c
+++ b/arch/arm/mach-ep93xx/clock.c
@@ -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 at %ld MHz\n",
 		clk_pll1.rate / 1000000, clk_pll2.rate / 1000000);
 	pr_info("FCLK %ld MHz, HCLK %ld MHz, PCLK %ld MHz\n",
diff --git a/arch/arm/mach-ep93xx/core.c b/arch/arm/mach-ep93xx/core.c
index 8d3f77e9fa8..9092677f63e 100644
--- a/arch/arm/mach-ep93xx/core.c
+++ b/arch/arm/mach-ep93xx/core.c
@@ -31,10 +31,12 @@
 #include <linux/amba/serial.h>
 #include <linux/i2c.h>
 #include <linux/i2c-gpio.h>
+#include <linux/spi/spi.h>
 
 #include <mach/hardware.h>
 #include <mach/fb.h>
 #include <mach/ep93xx_keypad.h>
+#include <mach/ep93xx_spi.h>
 
 #include <asm/mach/map.h>
 #include <asm/mach/time.h>
@@ -430,6 +432,56 @@ void __init ep93xx_register_i2c(struct i2c_gpio_platform_data *data,
 	platform_device_register(&ep93xx_i2c_device);
 }
 
+/*************************************************************************
+ * EP93xx SPI peripheral handling
+ *************************************************************************/
+static struct ep93xx_spi_info ep93xx_spi_master_data;
+
+static struct resource ep93xx_spi_resources[] = {
+	{
+		.start	= EP93XX_SPI_PHYS_BASE,
+		.end	= EP93XX_SPI_PHYS_BASE + 0x18 - 1,
+		.flags	= IORESOURCE_MEM,
+	},
+	{
+		.start	= IRQ_EP93XX_SSP,
+		.end	= IRQ_EP93XX_SSP,
+		.flags	= IORESOURCE_IRQ,
+	},
+};
+
+static struct platform_device ep93xx_spi_device = {
+	.name		= "ep93xx-spi",
+	.id		= 0,
+	.dev		= {
+		.platform_data = &ep93xx_spi_master_data,
+	},
+	.num_resources	= ARRAY_SIZE(ep93xx_spi_resources),
+	.resource	= ep93xx_spi_resources,
+};
+
+/**
+ * ep93xx_register_spi() - registers spi platform device
+ * @info: ep93xx board specific spi master info (__initdata)
+ * @devices: SPI devices to register (__initdata)
+ * @num: number of SPI devices to register
+ *
+ * This function registers platform device for the EP93xx SPI controller and
+ * also makes sure that SPI pins are muxed so that I2S is not using those pins.
+ */
+void __init ep93xx_register_spi(struct ep93xx_spi_info *info,
+				struct spi_board_info *devices, int num)
+{
+	/*
+	 * When SPI is used, we need to make sure that I2S is muxed off from
+	 * SPI pins.
+	 */
+	ep93xx_devcfg_clear_bits(EP93XX_SYSCON_DEVCFG_I2SONSSP);
+
+	ep93xx_spi_master_data = *info;
+	spi_register_board_info(devices, num);
+	platform_device_register(&ep93xx_spi_device);
+}
 
 /*************************************************************************
  * EP93xx LEDs
diff --git a/arch/arm/mach-ep93xx/include/mach/ep93xx-regs.h b/arch/arm/mach-ep93xx/include/mach/ep93xx-regs.h
index 93e2ecc79ce..b1e096f0c2d 100644
--- a/arch/arm/mach-ep93xx/include/mach/ep93xx-regs.h
+++ b/arch/arm/mach-ep93xx/include/mach/ep93xx-regs.h
@@ -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)
diff --git a/arch/arm/mach-ep93xx/include/mach/platform.h b/arch/arm/mach-ep93xx/include/mach/platform.h
index b663390b4d8..9a4413dd44b 100644
--- a/arch/arm/mach-ep93xx/include/mach/platform.h
+++ b/arch/arm/mach-ep93xx/include/mach/platform.h
@@ -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
 {
@@ -44,6 +46,8 @@ unsigned int ep93xx_chip_revision(void);
 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);