[ARM] Orion: implement power-off method for Kurobox Pro

This patch implements the communication with the microcontroller on the
Kurobox Pro and Linkstation Pro/Live boards.  This is allowing to send
the commands needed to power-off the board correctly.

Signed-off-by: Sylver Bruneau <sylver.bruneau@googlemail.com>
Acked-by: Russell King <linux@arm.linux.org.uk>
Signed-off-by: Lennert Buytenhek <buytenh@marvell.com>

1 files changed, 143 insertions, 4 deletions

diff --git a/arch/arm/mach-orion5x/kurobox_pro-setup.c b/arch/arm/mach-orion5x/kurobox_pro-setup.c
index 8b4a8aa5a836..37b4faa6ace7 100644
--- a/arch/arm/mach-orion5x/kurobox_pro-setup.c
+++ b/arch/arm/mach-orion5x/kurobox_pro-setup.c
@@ -13,10 +13,12 @@
 #include <linux/platform_device.h>
 #include <linux/pci.h>
 #include <linux/irq.h>
+#include <linux/delay.h>
 #include <linux/mtd/physmap.h>
 #include <linux/mtd/nand.h>
 #include <linux/mv643xx_eth.h>
 #include <linux/i2c.h>
+#include <linux/serial_reg.h>
 #include <linux/ata_platform.h>
 #include <asm/mach-types.h>
 #include <asm/gpio.h>
@@ -175,6 +177,140 @@ static struct mv_sata_platform_data kurobox_pro_sata_data = {
 };
 
 /*****************************************************************************
+ * Kurobox Pro specific power off method via UART1-attached microcontroller
+ ****************************************************************************/
+
+#define UART1_REG(x)    (UART1_VIRT_BASE + ((UART_##x) << 2))
+
+static int kurobox_pro_miconread(unsigned char *buf, int count)
+{
+        int i;
+        int timeout;
+
+        for (i = 0; i < count; i++) {
+                timeout = 10;
+
+                while (!(readl(UART1_REG(LSR)) & UART_LSR_DR)) {
+                        if (--timeout == 0)
+                                break;
+                        udelay(1000);
+                }
+
+                if (timeout == 0)
+                        break;
+                buf[i] = readl(UART1_REG(RX));
+        }
+
+        /* return read bytes */
+        return i;
+}
+
+static int kurobox_pro_miconwrite(const unsigned char *buf, int count)
+{
+        int i = 0;
+
+        while (count--) {
+                while (!(readl(UART1_REG(LSR)) & UART_LSR_THRE))
+                        barrier();
+                writel(buf[i++], UART1_REG(TX));
+        }
+
+        return 0;
+}
+
+static int kurobox_pro_miconsend(const unsigned char *data, int count)
+{
+        int i;
+        unsigned char checksum = 0;
+        unsigned char recv_buf[40];
+        unsigned char send_buf[40];
+        unsigned char correct_ack[3];
+        int retry = 2;
+
+        /* Generate checksum */
+        for (i = 0; i < count; i++)
+                checksum -=  data[i];
+
+        do {
+                /* Send data */
+                kurobox_pro_miconwrite(data, count);
+
+                /* send checksum */
+                kurobox_pro_miconwrite(&checksum, 1);
+
+                if (kurobox_pro_miconread(recv_buf, sizeof(recv_buf)) <= 3) {
+                        printk(KERN_ERR ">%s: receive failed.\n", __func__);
+
+                        /* send preamble to clear the receive buffer */
+                        memset(&send_buf, 0xff, sizeof(send_buf));
+                        kurobox_pro_miconwrite(send_buf, sizeof(send_buf));
+
+                        /* make dummy reads */
+                        mdelay(100);
+                        kurobox_pro_miconread(recv_buf, sizeof(recv_buf));
+                } else {
+                        /* Generate expected ack */
+                        correct_ack[0] = 0x01;
+                        correct_ack[1] = data[1];
+                        correct_ack[2] = 0x00;
+
+                        /* checksum Check */
+                        if ((recv_buf[0] + recv_buf[1] + recv_buf[2] +
+                             recv_buf[3]) & 0xFF) {
+                                printk(KERN_ERR ">%s: Checksum Error : "
+                                        "Received data[%02x, %02x, %02x, %02x]"
+                                        "\n", __func__, recv_buf[0],
+                                        recv_buf[1], recv_buf[2], recv_buf[3]);
+                        } else {
+                                /* Check Received Data */
+                                if (correct_ack[0] == recv_buf[0] &&
+                                    correct_ack[1] == recv_buf[1] &&
+                                    correct_ack[2] == recv_buf[2]) {
+                                        /* Interval for next command */
+                                        mdelay(10);
+
+                                        /* Receive ACK */
+                                        return 0;
+                                }
+                        }
+                        /* Received NAK or illegal Data */
+                        printk(KERN_ERR ">%s: Error : NAK or Illegal Data "
+                                        "Received\n", __func__);
+                }
+        } while (retry--);
+
+        /* Interval for next command */
+        mdelay(10);
+
+        return -1;
+}
+
+static void kurobox_pro_power_off(void)
+{
+        const unsigned char watchdogkill[]      = {0x01, 0x35, 0x00};
+        const unsigned char shutdownwait[]      = {0x00, 0x0c};
+        const unsigned char poweroff[]          = {0x00, 0x06};
+        /* 38400 baud divisor */
+        const unsigned divisor = ((ORION5X_TCLK + (8 * 38400)) / (16 * 38400));
+
+        pr_info("%s: triggering power-off...\n", __func__);
+
+        /* hijack uart1 and reset into sane state (38400,8n1,even parity) */
+        writel(0x83, UART1_REG(LCR));
+        writel(divisor & 0xff, UART1_REG(DLL));
+        writel((divisor >> 8) & 0xff, UART1_REG(DLM));
+        writel(0x1b, UART1_REG(LCR));
+        writel(0x00, UART1_REG(IER));
+        writel(0x07, UART1_REG(FCR));
+        writel(0x00, UART1_REG(MCR));
+
+        /* Send the commands to shutdown the Kurobox Pro */
+        kurobox_pro_miconsend(watchdogkill, sizeof(watchdogkill)) ;
+        kurobox_pro_miconsend(shutdownwait, sizeof(shutdownwait)) ;
+        kurobox_pro_miconsend(poweroff, sizeof(poweroff));
+}
+
+/*****************************************************************************
  * General Setup
  ****************************************************************************/
 static struct orion5x_mpp_mode kurobox_pro_mpp_modes[] __initdata = {
@@ -194,10 +330,10 @@ static struct orion5x_mpp_mode kurobox_pro_mpp_modes[] __initdata = {
         { 13, MPP_SATA_LED },           /* SATA 1 presence */
         { 14, MPP_SATA_LED },           /* SATA 0 active */
         { 15, MPP_SATA_LED },           /* SATA 1 active */
-        { 16, MPP_UNUSED },
-        { 17, MPP_UNUSED },
-        { 18, MPP_UNUSED },
-        { 19, MPP_UNUSED },
+        { 16, MPP_UART },               /* UART1 RXD */
+        { 17, MPP_UART },               /* UART1 TXD */
+        { 18, MPP_UART },               /* UART1 CTSn */
+        { 19, MPP_UART },               /* UART1 RTSn */
         { -1 },
 };
 
@@ -231,6 +367,9 @@ static void __init kurobox_pro_init(void)
         }
 
         i2c_register_board_info(0, &kurobox_pro_i2c_rtc, 1);
+
+        /* register Kurobox Pro specific power-off method */
+        pm_power_off = kurobox_pro_power_off;
 }
 
 #ifdef CONFIG_MACH_KUROBOX_PRO