[PATCH 3/3] watchdog: bcm7038_wdt: support BCM4908 SoC
Rafał Miłecki
zajec5 at gmail.com
Thu Oct 28 02:30:59 PDT 2021
From: Rafał Miłecki <rafal at milecki.pl>
Hardware supported by this driver goes back to the old bcm63xx days. It
was then reused in BCM7038 and later also in BCM4908.
Depending on SoC model registers layout differs a bit. This commit
introduces support for per-chipset registers offsets & adds BCM4908
layout.
Later on BCM63xx SoCs support should be added too (probably as platform
devices due to missing DT). Eventually this driver should replace
bcm63xx_wdt.c.
Signed-off-by: Rafał Miłecki <rafal at milecki.pl>
---
drivers/watchdog/Kconfig | 2 +-
drivers/watchdog/bcm7038_wdt.c | 89 ++++++++++++++++++++++++++--------
2 files changed, 69 insertions(+), 22 deletions(-)
diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
index bf59faeb3de1..324aa942b182 100644
--- a/drivers/watchdog/Kconfig
+++ b/drivers/watchdog/Kconfig
@@ -1756,7 +1756,7 @@ config BCM7038_WDT
tristate "BCM7038 Watchdog"
select WATCHDOG_CORE
depends on HAS_IOMEM
- depends on ARCH_BRCMSTB || BMIPS_GENERIC || COMPILE_TEST
+ depends on ARCH_BCM4908 || ARCH_BRCMSTB || BMIPS_GENERIC || COMPILE_TEST
help
Watchdog driver for the built-in hardware in Broadcom 7038 and
later SoCs used in set-top boxes. BCM7038 was made public
diff --git a/drivers/watchdog/bcm7038_wdt.c b/drivers/watchdog/bcm7038_wdt.c
index acaaa0005d5b..352689f869c1 100644
--- a/drivers/watchdog/bcm7038_wdt.c
+++ b/drivers/watchdog/bcm7038_wdt.c
@@ -9,6 +9,7 @@
#include <linux/io.h>
#include <linux/module.h>
#include <linux/of.h>
+#include <linux/of_device.h>
#include <linux/platform_device.h>
#include <linux/pm.h>
#include <linux/watchdog.h>
@@ -18,14 +19,17 @@
#define WDT_STOP_1 0xee00
#define WDT_STOP_2 0x00ee
-#define WDT_TIMEOUT_REG 0x0
-#define WDT_CMD_REG 0x4
-
#define WDT_MIN_TIMEOUT 1 /* seconds */
#define WDT_DEFAULT_TIMEOUT 30 /* seconds */
#define WDT_DEFAULT_RATE 27000000
+enum bcm63xx_wdt_soc {
+ BCM63XX_WDT_SOC_BCM4908,
+ BCM63XX_WDT_SOC_BCM7038,
+};
+
struct bcm7038_watchdog {
+ enum bcm63xx_wdt_soc soc;
void __iomem *base;
struct watchdog_device wdd;
u32 rate;
@@ -34,8 +38,52 @@ struct bcm7038_watchdog {
static bool nowayout = WATCHDOG_NOWAYOUT;
-static inline void bcm7038_wdt_write(u32 value, void __iomem *addr)
+static const struct of_device_id bcm7038_wdt_match[] = {
+ { .compatible = "brcm,bcm4908-wdt", .data = (const void *)BCM63XX_WDT_SOC_BCM4908, },
+ { .compatible = "brcm,bcm7038-wdt", .data = (const void *)BCM63XX_WDT_SOC_BCM7038, },
+ {},
+};
+MODULE_DEVICE_TABLE(of, bcm7038_wdt_match);
+
+enum bcm7038_wdt_regs {
+ BCM63XX_WDT_REG_DEFVAL = 0,
+ BCM63XX_WDT_REG_CTL,
+ BCM63XX_WDT_REG_SOFTRESET,
+};
+
+static const u16 bcm7038_wdt_regs_bcm4908[] = {
+ [BCM63XX_WDT_REG_DEFVAL] = 0x28,
+ [BCM63XX_WDT_REG_CTL] = 0x2c,
+ [BCM63XX_WDT_REG_SOFTRESET] = 0x34,
+};
+
+static const u16 bcm7038_wdt_regs_bcm7038[] = {
+ [BCM63XX_WDT_REG_DEFVAL] = 0x00,
+ [BCM63XX_WDT_REG_CTL] = 0x04,
+};
+
+static void __iomem *bcm7038_wdt_reg_addr(struct watchdog_device *wdog,
+ enum bcm7038_wdt_regs reg)
{
+ struct bcm7038_watchdog *wdt = watchdog_get_drvdata(wdog);
+ void __iomem *addr = wdt->base;
+
+ switch (wdt->soc) {
+ case BCM63XX_WDT_SOC_BCM4908:
+ return addr + bcm7038_wdt_regs_bcm4908[reg];
+ case BCM63XX_WDT_SOC_BCM7038:
+ return addr + bcm7038_wdt_regs_bcm7038[reg];
+ default:
+ WARN_ON(1);
+ return NULL;
+ }
+}
+
+static void bcm7038_wdt_write(struct watchdog_device *wdog,
+ enum bcm7038_wdt_regs reg, u32 value)
+{
+ void __iomem *addr = bcm7038_wdt_reg_addr(wdog, reg);
+
/* MIPS chips strapped for BE will automagically configure the
* peripheral registers for CPU-native byte order.
*/
@@ -45,8 +93,11 @@ static inline void bcm7038_wdt_write(u32 value, void __iomem *addr)
writel_relaxed(value, addr);
}
-static inline u32 bcm7038_wdt_read(void __iomem *addr)
+static inline u32 bcm7038_wdt_read(struct watchdog_device *wdog,
+ enum bcm7038_wdt_regs reg)
{
+ void __iomem *addr = bcm7038_wdt_reg_addr(wdog, reg);
+
if (IS_ENABLED(CONFIG_MIPS) && IS_ENABLED(CONFIG_CPU_BIG_ENDIAN))
return __raw_readl(addr);
else
@@ -60,15 +111,13 @@ static void bcm7038_wdt_set_timeout_reg(struct watchdog_device *wdog)
timeout = wdt->rate * wdog->timeout;
- bcm7038_wdt_write(timeout, wdt->base + WDT_TIMEOUT_REG);
+ bcm7038_wdt_write(wdog, BCM63XX_WDT_REG_DEFVAL, timeout);
}
static int bcm7038_wdt_ping(struct watchdog_device *wdog)
{
- struct bcm7038_watchdog *wdt = watchdog_get_drvdata(wdog);
-
- bcm7038_wdt_write(WDT_START_1, wdt->base + WDT_CMD_REG);
- bcm7038_wdt_write(WDT_START_2, wdt->base + WDT_CMD_REG);
+ bcm7038_wdt_write(wdog, BCM63XX_WDT_REG_CTL, WDT_START_1);
+ bcm7038_wdt_write(wdog, BCM63XX_WDT_REG_CTL, WDT_START_2);
return 0;
}
@@ -83,10 +132,8 @@ static int bcm7038_wdt_start(struct watchdog_device *wdog)
static int bcm7038_wdt_stop(struct watchdog_device *wdog)
{
- struct bcm7038_watchdog *wdt = watchdog_get_drvdata(wdog);
-
- bcm7038_wdt_write(WDT_STOP_1, wdt->base + WDT_CMD_REG);
- bcm7038_wdt_write(WDT_STOP_2, wdt->base + WDT_CMD_REG);
+ bcm7038_wdt_write(wdog, BCM63XX_WDT_REG_CTL, WDT_STOP_1);
+ bcm7038_wdt_write(wdog, BCM63XX_WDT_REG_CTL, WDT_STOP_2);
return 0;
}
@@ -107,7 +154,7 @@ static unsigned int bcm7038_wdt_get_timeleft(struct watchdog_device *wdog)
struct bcm7038_watchdog *wdt = watchdog_get_drvdata(wdog);
u32 time_left;
- time_left = bcm7038_wdt_read(wdt->base + WDT_CMD_REG);
+ time_left = bcm7038_wdt_read(wdog, BCM63XX_WDT_REG_CTL);
return time_left / wdt->rate;
}
@@ -134,6 +181,7 @@ static void bcm7038_clk_disable_unprepare(void *data)
static int bcm7038_wdt_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
+ const struct of_device_id *of_id;
struct bcm7038_watchdog *wdt;
int err;
@@ -143,6 +191,11 @@ static int bcm7038_wdt_probe(struct platform_device *pdev)
platform_set_drvdata(pdev, wdt);
+ of_id = of_match_device(bcm7038_wdt_match, dev);
+ if (!of_id)
+ return -EINVAL;
+ wdt->soc = (enum bcm63xx_wdt_soc)of_id->data;
+
wdt->base = devm_platform_ioremap_resource(pdev, 0);
if (IS_ERR(wdt->base))
return PTR_ERR(wdt->base);
@@ -211,12 +264,6 @@ static int bcm7038_wdt_resume(struct device *dev)
static SIMPLE_DEV_PM_OPS(bcm7038_wdt_pm_ops, bcm7038_wdt_suspend,
bcm7038_wdt_resume);
-static const struct of_device_id bcm7038_wdt_match[] = {
- { .compatible = "brcm,bcm7038-wdt" },
- {},
-};
-MODULE_DEVICE_TABLE(of, bcm7038_wdt_match);
-
static struct platform_driver bcm7038_wdt_driver = {
.probe = bcm7038_wdt_probe,
.driver = {
--
2.31.1
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