[ARM PATCH] 2388/1: Add SSP control code for Sharp SL-C7xx Series (Corgi)

Patch from Richard Purdie

The Sharp SL-C7xx Series (Corgi) has 3 devices connected to the SSP
interface each needing different configurations of the port.
This code provides the necessary access and locking so drivers can
access these components. It uses the functions provided by the PXA
SSP driver to access the port.
It also adds some machine specific GPIO definitions used by this
code and adds some comments to existing definitions.

Signed-off-by: Richard Purdie
Signed-off-by: Russell King

3 files changed, 254 insertions, 1 deletions

diff --git a/arch/arm/mach-pxa/Makefile b/arch/arm/mach-pxa/Makefile
index 0464f512de9530..d480bd54c95d78 100644
--- a/arch/arm/mach-pxa/Makefile
+++ b/arch/arm/mach-pxa/Makefile
@@ -11,7 +11,7 @@ obj-$(CONFIG_PXA27x) += pxa27x.o
 obj-$(CONFIG_ARCH_LUBBOCK) += lubbock.o
 obj-$(CONFIG_MACH_MAINSTONE) += mainstone.o
 obj-$(CONFIG_ARCH_PXA_IDP) += idp.o
-obj-$(CONFIG_PXA_SHARPSL)	+= corgi.o
+obj-$(CONFIG_PXA_SHARPSL)	+= corgi.o corgi_ssp.o ssp.o
 
 # Support for blinky lights
 led-y := leds.o
diff --git a/arch/arm/mach-pxa/corgi.c b/arch/arm/mach-pxa/corgi.c
index 8173808121f77f..716643c7df2a4f 100644
--- a/arch/arm/mach-pxa/corgi.c
+++ b/arch/arm/mach-pxa/corgi.c
@@ -68,8 +68,14 @@ static struct platform_device corgiscoop_device = {
 	.resource	= corgi_scoop_resources,
 };
 
+static struct platform_device corgissp_device = {
+	.name		= "corgi-ssp",
+	.id		= -1,
+};
+
 static struct platform_device *devices[] __initdata = {
 	&corgiscoop_device,
+	&corgissp_device,
 };
 
 static struct sharpsl_flash_param_info sharpsl_flash_param;
diff --git a/arch/arm/mach-pxa/corgi_ssp.c b/arch/arm/mach-pxa/corgi_ssp.c
new file mode 100644
index 00000000000000..1d2a881f3b7e6b
--- /dev/null
+++ b/arch/arm/mach-pxa/corgi_ssp.c
@@ -0,0 +1,247 @@
+/*
+ *  SSP control code for Sharp Corgi devices
+ *
+ *  Copyright (c) 2004 Richard Purdie
+ *
+ *  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/module.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <asm/hardware.h>
+
+#include <asm/arch/ssp.h>
+#include <asm/arch/corgi.h>
+#include <asm/arch/pxa-regs.h>
+
+static spinlock_t corgi_ssp_lock = SPIN_LOCK_UNLOCKED;
+static struct ssp_dev corgi_ssp_dev;
+static struct ssp_state corgi_ssp_state;
+
+/*
+ * There are three devices connected to the SSP interface:
+ *   1. A touchscreen controller (TI ADS7846 compatible)
+ *   2. An LCD contoller (with some Backlight functionality)
+ *   3. A battery moinitoring IC (Maxim MAX1111)
+ *
+ * Each device uses a different speed/mode of communication.
+ *
+ * The touchscreen is very sensitive and the most frequently used
+ * so the port is left configured for this.
+ *
+ * Devices are selected using Chip Selects on GPIOs.
+ */
+
+/*
+ *  ADS7846 Routines
+ */
+unsigned long corgi_ssp_ads7846_putget(ulong data)
+{
+	unsigned long ret,flag;
+
+	spin_lock_irqsave(&corgi_ssp_lock, flag);
+	GPCR0 = GPIO_bit(CORGI_GPIO_ADS7846_CS);
+
+	ssp_write_word(&corgi_ssp_dev,data);
+	ret = ssp_read_word(&corgi_ssp_dev);
+
+	GPSR0 = GPIO_bit(CORGI_GPIO_ADS7846_CS);
+	spin_unlock_irqrestore(&corgi_ssp_lock, flag);
+
+	return ret;
+}
+
+/*
+ * NOTE: These functions should always be called in interrupt context
+ * and use the _lock and _unlock functions. They are very time sensitive.
+ */
+void corgi_ssp_ads7846_lock(void)
+{
+	spin_lock(&corgi_ssp_lock);
+	GPCR0 = GPIO_bit(CORGI_GPIO_ADS7846_CS);
+}
+
+void corgi_ssp_ads7846_unlock(void)
+{
+	GPSR0 = GPIO_bit(CORGI_GPIO_ADS7846_CS);
+	spin_unlock(&corgi_ssp_lock);
+}
+
+void corgi_ssp_ads7846_put(ulong data)
+{
+	ssp_write_word(&corgi_ssp_dev,data);
+}
+
+unsigned long corgi_ssp_ads7846_get(void)
+{
+	return ssp_read_word(&corgi_ssp_dev);
+}
+
+EXPORT_SYMBOL(corgi_ssp_ads7846_putget);
+EXPORT_SYMBOL(corgi_ssp_ads7846_lock);
+EXPORT_SYMBOL(corgi_ssp_ads7846_unlock);
+EXPORT_SYMBOL(corgi_ssp_ads7846_put);
+EXPORT_SYMBOL(corgi_ssp_ads7846_get);
+
+
+/*
+ *  LCD/Backlight Routines
+ */
+unsigned long corgi_ssp_dac_put(ulong data)
+{
+	unsigned long flag;
+
+	spin_lock_irqsave(&corgi_ssp_lock, flag);
+	GPCR0 = GPIO_bit(CORGI_GPIO_LCDCON_CS);
+
+	ssp_disable(&corgi_ssp_dev);
+	ssp_config(&corgi_ssp_dev, (SSCR0_Motorola | (SSCR0_DSS & 0x07 )), SSCR1_SPH, 0, SSCR0_SerClkDiv(76));
+	ssp_enable(&corgi_ssp_dev);
+
+	ssp_write_word(&corgi_ssp_dev,data);
+	/* Read null data back from device to prevent SSP overflow */
+	ssp_read_word(&corgi_ssp_dev);
+
+	ssp_disable(&corgi_ssp_dev);
+	ssp_config(&corgi_ssp_dev, (SSCR0_National | (SSCR0_DSS & 0x0b )), 0, 0, SSCR0_SerClkDiv(2));
+	ssp_enable(&corgi_ssp_dev);
+	GPSR0 = GPIO_bit(CORGI_GPIO_LCDCON_CS);
+	spin_unlock_irqrestore(&corgi_ssp_lock, flag);
+
+	return 0;
+}
+
+void corgi_ssp_lcdtg_send(u8 adrs, u8 data)
+{
+	corgi_ssp_dac_put(((adrs & 0x07) << 5) | (data & 0x1f));
+}
+
+void corgi_ssp_blduty_set(int duty)
+{
+	corgi_ssp_lcdtg_send(0x02,duty);
+}
+
+EXPORT_SYMBOL(corgi_ssp_lcdtg_send);
+EXPORT_SYMBOL(corgi_ssp_blduty_set);
+
+/*
+ *  Max1111 Routines
+ */
+int corgi_ssp_max1111_get(ulong data)
+{
+	unsigned long flag;
+	int voltage,voltage1,voltage2;
+
+	spin_lock_irqsave(&corgi_ssp_lock, flag);
+	GPCR0 = GPIO_bit(CORGI_GPIO_MAX1111_CS);
+	ssp_disable(&corgi_ssp_dev);
+	ssp_config(&corgi_ssp_dev, (SSCR0_Motorola | (SSCR0_DSS & 0x07 )), 0, 0, SSCR0_SerClkDiv(8));
+	ssp_enable(&corgi_ssp_dev);
+
+	udelay(1);
+
+	/* TB1/RB1 */
+	ssp_write_word(&corgi_ssp_dev,data);
+	ssp_read_word(&corgi_ssp_dev); /* null read */
+
+	/* TB12/RB2 */
+	ssp_write_word(&corgi_ssp_dev,0);
+	voltage1=ssp_read_word(&corgi_ssp_dev);
+
+	/* TB13/RB3*/
+	ssp_write_word(&corgi_ssp_dev,0);
+	voltage2=ssp_read_word(&corgi_ssp_dev);
+
+	ssp_disable(&corgi_ssp_dev);
+	ssp_config(&corgi_ssp_dev, (SSCR0_National | (SSCR0_DSS & 0x0b )), 0, 0, SSCR0_SerClkDiv(2));
+	ssp_enable(&corgi_ssp_dev);
+	GPSR0 = GPIO_bit(CORGI_GPIO_MAX1111_CS);
+	spin_unlock_irqrestore(&corgi_ssp_lock, flag);
+
+	if (voltage1 & 0xc0 || voltage2 & 0x3f)
+		voltage = -1;
+	else
+		voltage = ((voltage1 << 2) & 0xfc) | ((voltage2 >> 6) & 0x03);
+
+	return voltage;
+}
+
+EXPORT_SYMBOL(corgi_ssp_max1111_get);
+
+/*
+ *  Support Routines
+ */
+int __init corgi_ssp_probe(struct device *dev)
+{
+	int ret;
+
+	/* Chip Select - Disable All */
+	GPDR0 |= GPIO_bit(CORGI_GPIO_LCDCON_CS); /* output */
+	GPSR0 = GPIO_bit(CORGI_GPIO_LCDCON_CS);  /* High - Disable LCD Control/Timing Gen */
+	GPDR0 |= GPIO_bit(CORGI_GPIO_MAX1111_CS); /* output */
+	GPSR0 = GPIO_bit(CORGI_GPIO_MAX1111_CS);  /* High - Disable MAX1111*/
+	GPDR0 |= GPIO_bit(CORGI_GPIO_ADS7846_CS);  /* output */
+	GPSR0 = GPIO_bit(CORGI_GPIO_ADS7846_CS);   /* High - Disable ADS7846*/
+
+	ret=ssp_init(&corgi_ssp_dev,1);
+
+	if (ret)
+		printk(KERN_ERR "Unable to register SSP handler!\n");
+	else {
+		ssp_disable(&corgi_ssp_dev);
+		ssp_config(&corgi_ssp_dev, (SSCR0_National | (SSCR0_DSS & 0x0b )), 0, 0, SSCR0_SerClkDiv(2));
+		ssp_enable(&corgi_ssp_dev);
+	}
+
+	return ret;
+}
+
+static int corgi_ssp_remove(struct device *dev)
+{
+	ssp_exit(&corgi_ssp_dev);
+	return 0;
+}
+
+static int corgi_ssp_suspend(struct device *dev, u32 state, u32 level)
+{
+	if (level == SUSPEND_POWER_DOWN) {
+		ssp_save_state(&corgi_ssp_dev,&corgi_ssp_state);
+	}
+	return 0;
+}
+
+static int corgi_ssp_resume(struct device *dev, u32 level)
+{
+	if (level == RESUME_POWER_ON) {
+		GPSR0 = GPIO_bit(CORGI_GPIO_LCDCON_CS);  /* High - Disable LCD Control/Timing Gen */
+		GPSR0 = GPIO_bit(CORGI_GPIO_MAX1111_CS); /* High - Disable MAX1111*/
+		GPSR0 = GPIO_bit(CORGI_GPIO_ADS7846_CS); /* High - Disable ADS7846*/
+		ssp_restore_state(&corgi_ssp_dev,&corgi_ssp_state);
+		ssp_enable(&corgi_ssp_dev);
+	}
+	return 0;
+}
+
+static struct device_driver corgissp_driver = {
+	.name		= "corgi-ssp",
+	.bus		= &platform_bus_type,
+	.probe		= corgi_ssp_probe,
+	.remove		= corgi_ssp_remove,
+	.suspend	= corgi_ssp_suspend,
+	.resume		= corgi_ssp_resume,
+};
+
+int __init corgi_ssp_init(void)
+{
+	return driver_register(&corgissp_driver);
+}
+
+arch_initcall(corgi_ssp_init);