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authorKristoffer Ericson <Kristoffer_e1@hotmail.com>2007-07-20 18:22:57 +0100
committerRussell King <rmk+kernel@arm.linux.org.uk>2007-07-20 21:33:19 +0100
commit69ebb22277a53f612ccd632ceb73ed87c9093412 (patch)
treecb3d573e74f1d5faf877e116b7e4e77b02540917 /arch/arm/mach-sa1100/jornada720_ssp.c
parent7b4c965a0b74748269d05185a394c9dc121dd558 (diff)
[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>
Diffstat (limited to 'arch/arm/mach-sa1100/jornada720_ssp.c')
-rw-r--r--arch/arm/mach-sa1100/jornada720_ssp.c201
1 files changed, 201 insertions, 0 deletions
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);
+}