[ARM] 4506/1: HP Jornada 7XX: Addition of SSP Platform Driver

These patches add full SSP/MCU support for the HP Jornada 720
machine.  Its needed to handle keyboard, touchscreen, battery
and backlight/lcd.

The main driver exports functions and the header file exports
the command values. When talking to the MCU the general procedure
is to start MCU, send command (using ssp_inout(command)), the
proper reply is always TXDUMMY.  After receiving TXDUMMY you can
send the value you wish pushed (for example brightness level).
End with ssp_end() so the spinlock gets unlocked.

Drivers using this havent been implemented yet, but will shortly.

Signed-off-by: Kristoffer Ericson <Kristoffer.ericson@gmail.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

3 files changed, 214 insertions, 2 deletions

diff --git a/arch/arm/mach-sa1100/Kconfig b/arch/arm/mach-sa1100/Kconfig
index cd67ab1b217b..f99d9013905f 100644
--- a/arch/arm/mach-sa1100/Kconfig
+++ b/arch/arm/mach-sa1100/Kconfig
@@ -101,6 +101,16 @@ config SA1100_JORNADA720
           handheld computer.  See <http://www.hp.com/jornada/products/720>
           for details.
 
+config SA1100_JORNADA720_SSP
+        bool "HP Jornada 720 Extended SSP driver"
+        select SA1100_SSP
+        depends on SA1100_JORNADA720
+        help
+          Say Y here if you have a HP Jornada 7xx handheld computer and you
+          want to access devices connected to the MCU. Those include the
+          keyboard, touchscreen, backlight and battery. This driver also activates
+          the generic SSP which it extends.
+
 config SA1100_HACKKIT
         bool "HackKit Core CPU Board"
         help
@@ -145,8 +155,7 @@ config SA1100_SSP
         help
           Say Y here to enable support for the generic PIO SSP driver.
           This isn't for audio support, but for attached sensors and
-          other devices, eg for BadgePAD 4 sensor support, or Jornada
-          720 touchscreen support.
+          other devices, eg for BadgePAD 4 sensor support.
 
 config H3600_SLEEVE
         tristate "Compaq iPAQ Handheld sleeve support"
diff --git a/arch/arm/mach-sa1100/Makefile b/arch/arm/mach-sa1100/Makefile
index e27f15042a22..7a61e8d33ab7 100644
--- a/arch/arm/mach-sa1100/Makefile
+++ b/arch/arm/mach-sa1100/Makefile
@@ -31,6 +31,7 @@ obj-$(CONFIG_SA1100_HACKKIT)		+= hackkit.o
 led-$(CONFIG_SA1100_HACKKIT)            += leds-hackkit.o
 
 obj-$(CONFIG_SA1100_JORNADA720)         += jornada720.o
+obj-$(CONFIG_SA1100_JORNADA720_SSP)     += jornada720_ssp.o
 
 obj-$(CONFIG_SA1100_LART)               += lart.o
 led-$(CONFIG_SA1100_LART)               += leds-lart.o
@@ -51,3 +52,4 @@ obj-$(CONFIG_LEDS) += $(led-y)
 # Miscelaneous functions
 obj-$(CONFIG_PM)                        += pm.o sleep.o
 obj-$(CONFIG_SA1100_SSP)                += ssp.o
+
diff --git a/arch/arm/mach-sa1100/jornada720_ssp.c b/arch/arm/mach-sa1100/jornada720_ssp.c
new file mode 100644
index 000000000000..0a45e1ac8ad6
--- /dev/null
+++ b/arch/arm/mach-sa1100/jornada720_ssp.c
@@ -0,0 +1,201 @@
+/**
+ *  arch/arm/mac-sa1100/jornada720_ssp.c
+ *
+ *  Copyright (C) 2006/2007 Kristoffer Ericson <Kristoffer.Ericson@gmail.com>
+ *   Copyright (C) 2006 Filip Zyzniewski <filip.zyzniewski@tefnet.pl>
+ *
+ * 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.
+ *
+ *  SSP driver for the HP Jornada 710/720/728
+ */
+
+#include <linux/delay.h>
+#include <linux/errno.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/sched.h>
+#include <linux/slab.h>
+
+#include <asm/hardware.h>
+#include <asm/hardware/ssp.h>
+#include <asm/arch/jornada720.h>
+
+static DEFINE_SPINLOCK(jornada_ssp_lock);
+static unsigned long jornada_ssp_flags;
+
+/**
+ * jornada_ssp_reverse - reverses input byte
+ *
+ * we need to reverse all data we recieve from the mcu due to its physical location
+ * returns : 01110111 -> 11101110
+ */
+u8 inline jornada_ssp_reverse(u8 byte)
+{
+        return
+                ((0x80 & byte) >> 7) |
+                ((0x40 & byte) >> 5) |
+                ((0x20 & byte) >> 3) |
+                ((0x10 & byte) >> 1) |
+                ((0x08 & byte) << 1) |
+                ((0x04 & byte) << 3) |
+                ((0x02 & byte) << 5) |
+                ((0x01 & byte) << 7);
+};
+EXPORT_SYMBOL(jornada_ssp_reverse);
+
+/**
+ * jornada_ssp_byte - waits for ready ssp bus and sends byte
+ *
+ * waits for fifo buffer to clear and then transmits, if it doesn't then we will
+ * timeout after <timeout> rounds. Needs mcu running before its called.
+ *
+ * returns : %mcu output on success
+ *         : %-ETIMEOUT on timeout
+ */
+int jornada_ssp_byte(u8 byte)
+{
+        int timeout = 400000;
+        u16 ret;
+
+        while ((GPLR & GPIO_GPIO10)) {
+                if (!--timeout) {
+                        printk(KERN_WARNING "SSP: timeout while waiting for transmit\n");
+                        return -ETIMEDOUT;
+                }
+                cpu_relax();
+        }
+
+        ret = jornada_ssp_reverse(byte) << 8;
+
+        ssp_write_word(ret);
+        ssp_read_word(&ret);
+
+        return jornada_ssp_reverse(ret);
+};
+EXPORT_SYMBOL(jornada_ssp_byte);
+
+/**
+ * jornada_ssp_inout - decide if input is command or trading byte
+ *
+ * returns : (jornada_ssp_byte(byte)) on success
+ *         : %-ETIMEOUT on timeout failure
+ */
+int jornada_ssp_inout(u8 byte)
+{
+        int ret, i;
+
+        /* true means command byte */
+        if (byte != TXDUMMY) {
+                ret = jornada_ssp_byte(byte);
+                /* Proper return to commands is TxDummy */
+                if (ret != TXDUMMY) {
+                        for (i = 0; i < 256; i++)/* flushing bus */
+                                if (jornada_ssp_byte(TXDUMMY) == -1)
+                                        break;
+                        return -ETIMEDOUT;
+                }
+        } else /* Exchange TxDummy for data */
+                ret = jornada_ssp_byte(TXDUMMY);
+
+        return ret;
+};
+EXPORT_SYMBOL(jornada_ssp_inout);
+
+/**
+ * jornada_ssp_start - enable mcu
+ *
+ */
+int jornada_ssp_start()
+{
+        spin_lock_irqsave(&jornada_ssp_lock, jornada_ssp_flags);
+        GPCR = GPIO_GPIO25;
+        udelay(50);
+        return 0;
+};
+EXPORT_SYMBOL(jornada_ssp_start);
+
+/**
+ * jornada_ssp_end - disable mcu and turn off lock
+ *
+ */
+int jornada_ssp_end()
+{
+        GPSR = GPIO_GPIO25;
+        spin_unlock_irqrestore(&jornada_ssp_lock, jornada_ssp_flags);
+        return 0;
+};
+EXPORT_SYMBOL(jornada_ssp_end);
+
+static int __init jornada_ssp_probe(struct platform_device *dev)
+{
+        int ret;
+
+        GPSR = GPIO_GPIO25;
+
+        ret = ssp_init();
+
+        /* worked fine, lets not bother with anything else */
+        if (!ret) {
+                printk(KERN_INFO "SSP: device initialized with irq\n");
+                return ret;
+        }
+
+        printk(KERN_WARNING "SSP: initialization failed, trying non-irq solution \n");
+
+        /* init of Serial 4 port */
+        Ser4MCCR0 = 0;
+        Ser4SSCR0 = 0x0387;
+        Ser4SSCR1 = 0x18;
+
+        /* clear out any left over data */
+        ssp_flush();
+
+        /* enable MCU */
+        jornada_ssp_start();
+
+        /* see if return value makes sense */
+        ret = jornada_ssp_inout(GETBRIGHTNESS);
+
+        /* seems like it worked, just feed it with TxDummy to get rid of data */
+        if (ret == TxDummy)
+                jornada_ssp_inout(TXDUMMY);
+
+        jornada_ssp_end();
+
+        /* failed, lets just kill everything */
+        if (ret == -ETIMEDOUT) {
+                printk(KERN_WARNING "SSP: attempts failed, bailing\n");
+                ssp_exit();
+                return -ENODEV;
+        }
+
+        /* all fine */
+        printk(KERN_INFO "SSP: device initialized\n");
+        return 0;
+};
+
+static int jornada_ssp_remove(struct platform_device *dev)
+{
+        /* Note that this doesnt actually remove the driver, since theres nothing to remove
+         * It just makes sure everything is turned off */
+        GPSR = GPIO_GPIO25;
+        ssp_exit();
+        return 0;
+};
+
+struct platform_driver jornadassp_driver = {
+        .probe  = jornada_ssp_probe,
+        .remove = jornada_ssp_remove,
+        .driver = {
+                .name   = "jornada_ssp",
+        },
+};
+
+static int __init jornada_ssp_init(void)
+{
+        return platform_driver_register(&jornadassp_driver);
+}