[PATCH] spi: sprd: Add the support of restarting the system
From: Baolin Wang
Date: Mon Mar 19 2018 - 22:42:14 EST
On Spreadtrum platform, we use one PMIC watchdog to reset the whole system
with loading one suitable timeout value (usually 50ms) for the watchdog.
In theory, we should implement the restart function in drivers/power/reset
subsystem to access the PMIC watchdog with regmap. When restart the system,
other cores will be stopped by IPI, but if other cores were accessing PMIC
with holding the regmap mutex lock, that will cause dead-lock issue if we
try to access the PMIC watchdog with regmap to restart the whole system.
Thus we can implement the restart function in ADI driver to avoid this
issue.
Signed-off-by: Baolin Wang <baolin.wang@xxxxxxxxxx>
Signed-off-by: Mark Brown <broonie@xxxxxxxxxx>
---
drivers/spi/spi-sprd-adi.c | 112 +++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 112 insertions(+)
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;
}
--
2.16.2