Add the rt linux 4.1.3-rt3 as base

[kvmfornfv.git] / kernel / arch / arm / mach-sa1100 / jornada720_ssp.c

diff --git a/kernel/arch/arm/mach-sa1100/jornada720_ssp.c b/kernel/arch/arm/mach-sa1100/jornada720_ssp.c
new file mode 100644 (file)
index 0000000..b143c46
--- /dev/null
+++ b/kernel/arch/arm/mach-sa1100/jornada720_ssp.c
@@ -0,0 +1,203 @@
+/**
+ *  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/io.h>
+
+#include <mach/hardware.h>
+#include <mach/jornada720.h>
+#include <asm/hardware/ssp.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 receive 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
+ *        : %-ETIMEDOUT 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
+ *         : %-ETIMEDOUT 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
+ *
+ */
+void jornada_ssp_start(void)
+{
+       spin_lock_irqsave(&jornada_ssp_lock, jornada_ssp_flags);
+       GPCR = GPIO_GPIO25;
+       udelay(50);
+       return;
+};
+EXPORT_SYMBOL(jornada_ssp_start);
+
+/**
+ * jornada_ssp_end - disable mcu and turn off lock
+ *
+ */
+void jornada_ssp_end(void)
+{
+       GPSR = GPIO_GPIO25;
+       spin_unlock_irqrestore(&jornada_ssp_lock, jornada_ssp_flags);
+       return;
+};
+EXPORT_SYMBOL(jornada_ssp_end);
+
+static int 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 doesn't 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);
+}
+
+module_init(jornada_ssp_init);