1 files changed, 112 insertions, 0 deletions

diff --git a/drivers/spi/spi-sprd-adi.c b/drivers/spi/spi-sprd-adi.c
index 74bbd045aac0..197d4b0d81af 100644
--- a/drivers/spi/spi-sprd-adi.c
+++ b/drivers/spi/spi-sprd-adi.c
@@ -4,6 +4,7 @@
  * SPDX-License-Identifier: GPL-2.0
  */
 
+#include <linux/delay.h>
 #include <linux/hwspinlock.h>
 #include <linux/init.h>
 #include <linux/io.h>
@@ -12,6 +13,7 @@
 #include <linux/of.h>
 #include <linux/of_device.h>
 #include <linux/platform_device.h>
+#include <linux/reboot.h>
 #include <linux/spi/spi.h>
 #include <linux/sizes.h>
 
@@ -67,6 +69,40 @@
 #define ADI_READ_TIMEOUT                2000
 #define REG_ADDR_LOW_MASK               GENMASK(11, 0)
 
+/* Registers definitions for PMIC watchdog controller */
+#define REG_WDG_LOAD_LOW                0x80
+#define REG_WDG_LOAD_HIGH               0x84
+#define REG_WDG_CTRL                    0x88
+#define REG_WDG_LOCK                    0xa0
+
+/* Bits definitions for register REG_WDG_CTRL */
+#define BIT_WDG_RUN                     BIT(1)
+#define BIT_WDG_RST                     BIT(3)
+
+/* Registers definitions for PMIC */
+#define PMIC_RST_STATUS                 0xee8
+#define PMIC_MODULE_EN                  0xc08
+#define PMIC_CLK_EN                     0xc18
+#define BIT_WDG_EN                      BIT(2)
+
+/* Definition of PMIC reset status register */
+#define HWRST_STATUS_RECOVERY           0x20
+#define HWRST_STATUS_NORMAL             0x40
+#define HWRST_STATUS_ALARM              0x50
+#define HWRST_STATUS_SLEEP              0x60
+#define HWRST_STATUS_FASTBOOT           0x30
+#define HWRST_STATUS_SPECIAL            0x70
+#define HWRST_STATUS_PANIC              0x80
+#define HWRST_STATUS_CFTREBOOT          0x90
+#define HWRST_STATUS_AUTODLOADER        0xa0
+#define HWRST_STATUS_IQMODE             0xb0
+#define HWRST_STATUS_SPRDISK            0xc0
+
+/* Use default timeout 50 ms that converts to watchdog values */
+#define WDG_LOAD_VAL                    ((50 * 1000) / 32768)
+#define WDG_LOAD_MASK                   GENMASK(15, 0)
+#define WDG_UNLOCK_KEY                  0xe551
+
 struct sprd_adi {
         struct spi_controller   *ctlr;
         struct device           *dev;
@@ -74,6 +110,7 @@ struct sprd_adi {
         struct hwspinlock       *hwlock;
         unsigned long           slave_vbase;
         unsigned long           slave_pbase;
+        struct notifier_block   restart_handler;
 };
 
 static int sprd_adi_check_paddr(struct sprd_adi *sadi, u32 paddr)
@@ -270,6 +307,72 @@ static int sprd_adi_transfer_one(struct spi_controller *ctlr,
         return 0;
 }
 
+static int sprd_adi_restart_handler(struct notifier_block *this,
+                                    unsigned long mode, void *cmd)
+{
+        struct sprd_adi *sadi = container_of(this, struct sprd_adi,
+                                             restart_handler);
+        u32 val, reboot_mode = 0;
+
+        if (!cmd)
+                reboot_mode = HWRST_STATUS_NORMAL;
+        else if (!strncmp(cmd, "recovery", 8))
+                reboot_mode = HWRST_STATUS_RECOVERY;
+        else if (!strncmp(cmd, "alarm", 5))
+                reboot_mode = HWRST_STATUS_ALARM;
+        else if (!strncmp(cmd, "fastsleep", 9))
+                reboot_mode = HWRST_STATUS_SLEEP;
+        else if (!strncmp(cmd, "bootloader", 10))
+                reboot_mode = HWRST_STATUS_FASTBOOT;
+        else if (!strncmp(cmd, "panic", 5))
+                reboot_mode = HWRST_STATUS_PANIC;
+        else if (!strncmp(cmd, "special", 7))
+                reboot_mode = HWRST_STATUS_SPECIAL;
+        else if (!strncmp(cmd, "cftreboot", 9))
+                reboot_mode = HWRST_STATUS_CFTREBOOT;
+        else if (!strncmp(cmd, "autodloader", 11))
+                reboot_mode = HWRST_STATUS_AUTODLOADER;
+        else if (!strncmp(cmd, "iqmode", 6))
+                reboot_mode = HWRST_STATUS_IQMODE;
+        else if (!strncmp(cmd, "sprdisk", 7))
+                reboot_mode = HWRST_STATUS_SPRDISK;
+        else
+                reboot_mode = HWRST_STATUS_NORMAL;
+
+        /* Record the reboot mode */
+        sprd_adi_read(sadi, sadi->slave_pbase + PMIC_RST_STATUS, &val);
+        val |= reboot_mode;
+        sprd_adi_write(sadi, sadi->slave_pbase + PMIC_RST_STATUS, val);
+
+        /* Enable the interface clock of the watchdog */
+        sprd_adi_read(sadi, sadi->slave_pbase + PMIC_MODULE_EN, &val);
+        val |= BIT_WDG_EN;
+        sprd_adi_write(sadi, sadi->slave_pbase + PMIC_MODULE_EN, val);
+
+        /* Enable the work clock of the watchdog */
+        sprd_adi_read(sadi, sadi->slave_pbase + PMIC_CLK_EN, &val);
+        val |= BIT_WDG_EN;
+        sprd_adi_write(sadi, sadi->slave_pbase + PMIC_CLK_EN, val);
+
+        /* Unlock the watchdog */
+        sprd_adi_write(sadi, sadi->slave_pbase + REG_WDG_LOCK, WDG_UNLOCK_KEY);
+
+        /* Load the watchdog timeout value, 50ms is always enough. */
+        sprd_adi_write(sadi, sadi->slave_pbase + REG_WDG_LOAD_LOW,
+                       WDG_LOAD_VAL & WDG_LOAD_MASK);
+        sprd_adi_write(sadi, sadi->slave_pbase + REG_WDG_LOAD_HIGH, 0);
+
+        /* Start the watchdog to reset system */
+        sprd_adi_read(sadi, sadi->slave_pbase + REG_WDG_CTRL, &val);
+        val |= BIT_WDG_RUN | BIT_WDG_RST;
+        sprd_adi_write(sadi, sadi->slave_pbase + REG_WDG_CTRL, val);
+
+        mdelay(1000);
+
+        dev_emerg(sadi->dev, "Unable to restart system\n");
+        return NOTIFY_DONE;
+}
+
 static void sprd_adi_hw_init(struct sprd_adi *sadi)
 {
         struct device_node *np = sadi->dev->of_node;
@@ -383,6 +486,14 @@ static int sprd_adi_probe(struct platform_device *pdev)
                 goto free_hwlock;
         }
 
+        sadi->restart_handler.notifier_call = sprd_adi_restart_handler;
+        sadi->restart_handler.priority = 128;
+        ret = register_restart_handler(&sadi->restart_handler);
+        if (ret) {
+                dev_err(&pdev->dev, "can not register restart handler\n");
+                goto free_hwlock;
+        }
+
         return 0;
 
 free_hwlock:
@@ -397,6 +508,7 @@ static int sprd_adi_remove(struct platform_device *pdev)
         struct spi_controller *ctlr = dev_get_drvdata(&pdev->dev);
         struct sprd_adi *sadi = spi_controller_get_devdata(ctlr);
 
+        unregister_restart_handler(&sadi->restart_handler);
         hwspin_lock_free(sadi->hwlock);
         return 0;
 }