| Message ID | 20190809115930.6050-2-paul@crapouillou.net (mailing list archive) |
|---|---|
| State | Not Applicable |
| Headers | show |
| Series | watchdog: jz4740: Driver update | expand |
On Fri, Aug 09, 2019 at 01:59:28PM +0200, Paul Cercueil wrote: > Instead of requesting the "ext" clock and handling the watchdog clock > divider and gating in the watchdog driver, we now request and use the > "wdt" clock that is supplied by the ingenic-timer "TCU" driver. > > The major benefit is that the watchdog's clock rate and parent can now > be specified from within devicetree, instead of hardcoded in the driver. > > Also, this driver won't poke anymore into the TCU registers to > enable/disable the clock, as this is now handled by the TCU driver. > > On the bad side, we break the ABI with devicetree - as we now request a > different clock. In this very specific case it is still okay, as every > Ingenic JZ47xx-based board out there compile the devicetree within the > kernel; so it's still time to push breaking changes, in order to get a > clean devicetree that won't break once it musn't. > > Signed-off-by: Paul Cercueil <paul@crapouillou.net> > Reviewed-by: Guenter Roeck <linux@roeck-us.net> > Tested-by: Mathieu Malaterre <malat@debian.org> > Tested-by: Artur Rojek <contact@artur-rojek.eu> Acked-by: Guenter Roeck <linux@roeck-us.net> > --- > drivers/watchdog/Kconfig | 1 + > drivers/watchdog/jz4740_wdt.c | 75 ++++++++++++++--------------------- > 2 files changed, 31 insertions(+), 45 deletions(-) > > diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig > index 8188963a405b..820d8a472310 100644 > --- a/drivers/watchdog/Kconfig > +++ b/drivers/watchdog/Kconfig > @@ -1645,6 +1645,7 @@ config INDYDOG > config JZ4740_WDT > tristate "Ingenic jz4740 SoC hardware watchdog" > depends on MACH_JZ4740 || MACH_JZ4780 > + depends on COMMON_CLK > select WATCHDOG_CORE > help > Hardware driver for the built-in watchdog timer on Ingenic jz4740 SoCs. > diff --git a/drivers/watchdog/jz4740_wdt.c b/drivers/watchdog/jz4740_wdt.c > index d4a90916dd38..07fbd9d96e84 100644 > --- a/drivers/watchdog/jz4740_wdt.c > +++ b/drivers/watchdog/jz4740_wdt.c > @@ -18,19 +18,6 @@ > #include <linux/err.h> > #include <linux/of.h> > > -#include <asm/mach-jz4740/timer.h> > - > -#define JZ_WDT_CLOCK_PCLK 0x1 > -#define JZ_WDT_CLOCK_RTC 0x2 > -#define JZ_WDT_CLOCK_EXT 0x4 > - > -#define JZ_WDT_CLOCK_DIV_1 (0 << TCU_TCSR_PRESCALE_LSB) > -#define JZ_WDT_CLOCK_DIV_4 (1 << TCU_TCSR_PRESCALE_LSB) > -#define JZ_WDT_CLOCK_DIV_16 (2 << TCU_TCSR_PRESCALE_LSB) > -#define JZ_WDT_CLOCK_DIV_64 (3 << TCU_TCSR_PRESCALE_LSB) > -#define JZ_WDT_CLOCK_DIV_256 (4 << TCU_TCSR_PRESCALE_LSB) > -#define JZ_WDT_CLOCK_DIV_1024 (5 << TCU_TCSR_PRESCALE_LSB) > - > #define DEFAULT_HEARTBEAT 5 > #define MAX_HEARTBEAT 2048 > > @@ -50,7 +37,8 @@ MODULE_PARM_DESC(heartbeat, > struct jz4740_wdt_drvdata { > struct watchdog_device wdt; > void __iomem *base; > - struct clk *rtc_clk; > + struct clk *clk; > + unsigned long clk_rate; > }; > > static int jz4740_wdt_ping(struct watchdog_device *wdt_dev) > @@ -65,32 +53,14 @@ static int jz4740_wdt_set_timeout(struct watchdog_device *wdt_dev, > unsigned int new_timeout) > { > struct jz4740_wdt_drvdata *drvdata = watchdog_get_drvdata(wdt_dev); > - unsigned int rtc_clk_rate; > - unsigned int timeout_value; > - unsigned short clock_div = JZ_WDT_CLOCK_DIV_1; > + u16 timeout_value = (u16)(drvdata->clk_rate * new_timeout); > u8 tcer; > > - rtc_clk_rate = clk_get_rate(drvdata->rtc_clk); > - > - timeout_value = rtc_clk_rate * new_timeout; > - while (timeout_value > 0xffff) { > - if (clock_div == JZ_WDT_CLOCK_DIV_1024) { > - /* Requested timeout too high; > - * use highest possible value. */ > - timeout_value = 0xffff; > - break; > - } > - timeout_value >>= 2; > - clock_div += (1 << TCU_TCSR_PRESCALE_LSB); > - } > - > tcer = readb(drvdata->base + TCU_REG_WDT_TCER); > writeb(0x0, drvdata->base + TCU_REG_WDT_TCER); > - writew(clock_div, drvdata->base + TCU_REG_WDT_TCSR); > > writew((u16)timeout_value, drvdata->base + TCU_REG_WDT_TDR); > writew(0x0, drvdata->base + TCU_REG_WDT_TCNT); > - writew(clock_div | JZ_WDT_CLOCK_RTC, drvdata->base + TCU_REG_WDT_TCSR); > > if (tcer & TCU_WDT_TCER_TCEN) > writeb(TCU_WDT_TCER_TCEN, drvdata->base + TCU_REG_WDT_TCER); > @@ -102,11 +72,15 @@ static int jz4740_wdt_set_timeout(struct watchdog_device *wdt_dev, > static int jz4740_wdt_start(struct watchdog_device *wdt_dev) > { > struct jz4740_wdt_drvdata *drvdata = watchdog_get_drvdata(wdt_dev); > + int ret; > u8 tcer; > > + ret = clk_prepare_enable(drvdata->clk); > + if (ret) > + return ret; > + > tcer = readb(drvdata->base + TCU_REG_WDT_TCER); > > - jz4740_timer_enable_watchdog(); > jz4740_wdt_set_timeout(wdt_dev, wdt_dev->timeout); > > /* Start watchdog if it wasn't started already */ > @@ -121,7 +95,7 @@ static int jz4740_wdt_stop(struct watchdog_device *wdt_dev) > struct jz4740_wdt_drvdata *drvdata = watchdog_get_drvdata(wdt_dev); > > writeb(0x0, drvdata->base + TCU_REG_WDT_TCER); > - jz4740_timer_disable_watchdog(); > + clk_disable_unprepare(drvdata->clk); > > return 0; > } > @@ -162,6 +136,8 @@ static int jz4740_wdt_probe(struct platform_device *pdev) > struct device *dev = &pdev->dev; > struct jz4740_wdt_drvdata *drvdata; > struct watchdog_device *jz4740_wdt; > + struct resource *res; > + long rate; > int ret; > > drvdata = devm_kzalloc(dev, sizeof(struct jz4740_wdt_drvdata), > @@ -169,15 +145,30 @@ static int jz4740_wdt_probe(struct platform_device *pdev) > if (!drvdata) > return -ENOMEM; > > - if (heartbeat < 1 || heartbeat > MAX_HEARTBEAT) > - heartbeat = DEFAULT_HEARTBEAT; > + drvdata->clk = devm_clk_get(&pdev->dev, "wdt"); > + if (IS_ERR(drvdata->clk)) { > + dev_err(&pdev->dev, "cannot find WDT clock\n"); > + return PTR_ERR(drvdata->clk); > + } > + > + /* Set smallest clock possible */ > + rate = clk_round_rate(drvdata->clk, 1); > + if (rate < 0) > + return rate; > > + ret = clk_set_rate(drvdata->clk, rate); > + if (ret) > + return ret; > + > + drvdata->clk_rate = rate; > jz4740_wdt = &drvdata->wdt; > jz4740_wdt->info = &jz4740_wdt_info; > jz4740_wdt->ops = &jz4740_wdt_ops; > - jz4740_wdt->timeout = heartbeat; > jz4740_wdt->min_timeout = 1; > - jz4740_wdt->max_timeout = MAX_HEARTBEAT; > + jz4740_wdt->max_timeout = 0xffff / rate; > + jz4740_wdt->timeout = clamp(heartbeat, > + jz4740_wdt->min_timeout, > + jz4740_wdt->max_timeout); > jz4740_wdt->parent = dev; > watchdog_set_nowayout(jz4740_wdt, nowayout); > watchdog_set_drvdata(jz4740_wdt, drvdata); > @@ -186,12 +177,6 @@ static int jz4740_wdt_probe(struct platform_device *pdev) > if (IS_ERR(drvdata->base)) > return PTR_ERR(drvdata->base); > > - drvdata->rtc_clk = devm_clk_get(dev, "rtc"); > - if (IS_ERR(drvdata->rtc_clk)) { > - dev_err(dev, "cannot find RTC clock\n"); > - return PTR_ERR(drvdata->rtc_clk); > - } > - > return devm_watchdog_register_device(dev, &drvdata->wdt); > } >
diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig index 8188963a405b..820d8a472310 100644 --- a/drivers/watchdog/Kconfig +++ b/drivers/watchdog/Kconfig @@ -1645,6 +1645,7 @@ config INDYDOG config JZ4740_WDT tristate "Ingenic jz4740 SoC hardware watchdog" depends on MACH_JZ4740 || MACH_JZ4780 + depends on COMMON_CLK select WATCHDOG_CORE help Hardware driver for the built-in watchdog timer on Ingenic jz4740 SoCs. diff --git a/drivers/watchdog/jz4740_wdt.c b/drivers/watchdog/jz4740_wdt.c index d4a90916dd38..07fbd9d96e84 100644 --- a/drivers/watchdog/jz4740_wdt.c +++ b/drivers/watchdog/jz4740_wdt.c @@ -18,19 +18,6 @@ #include <linux/err.h> #include <linux/of.h> -#include <asm/mach-jz4740/timer.h> - -#define JZ_WDT_CLOCK_PCLK 0x1 -#define JZ_WDT_CLOCK_RTC 0x2 -#define JZ_WDT_CLOCK_EXT 0x4 - -#define JZ_WDT_CLOCK_DIV_1 (0 << TCU_TCSR_PRESCALE_LSB) -#define JZ_WDT_CLOCK_DIV_4 (1 << TCU_TCSR_PRESCALE_LSB) -#define JZ_WDT_CLOCK_DIV_16 (2 << TCU_TCSR_PRESCALE_LSB) -#define JZ_WDT_CLOCK_DIV_64 (3 << TCU_TCSR_PRESCALE_LSB) -#define JZ_WDT_CLOCK_DIV_256 (4 << TCU_TCSR_PRESCALE_LSB) -#define JZ_WDT_CLOCK_DIV_1024 (5 << TCU_TCSR_PRESCALE_LSB) - #define DEFAULT_HEARTBEAT 5 #define MAX_HEARTBEAT 2048 @@ -50,7 +37,8 @@ MODULE_PARM_DESC(heartbeat, struct jz4740_wdt_drvdata { struct watchdog_device wdt; void __iomem *base; - struct clk *rtc_clk; + struct clk *clk; + unsigned long clk_rate; }; static int jz4740_wdt_ping(struct watchdog_device *wdt_dev) @@ -65,32 +53,14 @@ static int jz4740_wdt_set_timeout(struct watchdog_device *wdt_dev, unsigned int new_timeout) { struct jz4740_wdt_drvdata *drvdata = watchdog_get_drvdata(wdt_dev); - unsigned int rtc_clk_rate; - unsigned int timeout_value; - unsigned short clock_div = JZ_WDT_CLOCK_DIV_1; + u16 timeout_value = (u16)(drvdata->clk_rate * new_timeout); u8 tcer; - rtc_clk_rate = clk_get_rate(drvdata->rtc_clk); - - timeout_value = rtc_clk_rate * new_timeout; - while (timeout_value > 0xffff) { - if (clock_div == JZ_WDT_CLOCK_DIV_1024) { - /* Requested timeout too high; - * use highest possible value. */ - timeout_value = 0xffff; - break; - } - timeout_value >>= 2; - clock_div += (1 << TCU_TCSR_PRESCALE_LSB); - } - tcer = readb(drvdata->base + TCU_REG_WDT_TCER); writeb(0x0, drvdata->base + TCU_REG_WDT_TCER); - writew(clock_div, drvdata->base + TCU_REG_WDT_TCSR); writew((u16)timeout_value, drvdata->base + TCU_REG_WDT_TDR); writew(0x0, drvdata->base + TCU_REG_WDT_TCNT); - writew(clock_div | JZ_WDT_CLOCK_RTC, drvdata->base + TCU_REG_WDT_TCSR); if (tcer & TCU_WDT_TCER_TCEN) writeb(TCU_WDT_TCER_TCEN, drvdata->base + TCU_REG_WDT_TCER); @@ -102,11 +72,15 @@ static int jz4740_wdt_set_timeout(struct watchdog_device *wdt_dev, static int jz4740_wdt_start(struct watchdog_device *wdt_dev) { struct jz4740_wdt_drvdata *drvdata = watchdog_get_drvdata(wdt_dev); + int ret; u8 tcer; + ret = clk_prepare_enable(drvdata->clk); + if (ret) + return ret; + tcer = readb(drvdata->base + TCU_REG_WDT_TCER); - jz4740_timer_enable_watchdog(); jz4740_wdt_set_timeout(wdt_dev, wdt_dev->timeout); /* Start watchdog if it wasn't started already */ @@ -121,7 +95,7 @@ static int jz4740_wdt_stop(struct watchdog_device *wdt_dev) struct jz4740_wdt_drvdata *drvdata = watchdog_get_drvdata(wdt_dev); writeb(0x0, drvdata->base + TCU_REG_WDT_TCER); - jz4740_timer_disable_watchdog(); + clk_disable_unprepare(drvdata->clk); return 0; } @@ -162,6 +136,8 @@ static int jz4740_wdt_probe(struct platform_device *pdev) struct device *dev = &pdev->dev; struct jz4740_wdt_drvdata *drvdata; struct watchdog_device *jz4740_wdt; + struct resource *res; + long rate; int ret; drvdata = devm_kzalloc(dev, sizeof(struct jz4740_wdt_drvdata), @@ -169,15 +145,30 @@ static int jz4740_wdt_probe(struct platform_device *pdev) if (!drvdata) return -ENOMEM; - if (heartbeat < 1 || heartbeat > MAX_HEARTBEAT) - heartbeat = DEFAULT_HEARTBEAT; + drvdata->clk = devm_clk_get(&pdev->dev, "wdt"); + if (IS_ERR(drvdata->clk)) { + dev_err(&pdev->dev, "cannot find WDT clock\n"); + return PTR_ERR(drvdata->clk); + } + + /* Set smallest clock possible */ + rate = clk_round_rate(drvdata->clk, 1); + if (rate < 0) + return rate; + ret = clk_set_rate(drvdata->clk, rate); + if (ret) + return ret; + + drvdata->clk_rate = rate; jz4740_wdt = &drvdata->wdt; jz4740_wdt->info = &jz4740_wdt_info; jz4740_wdt->ops = &jz4740_wdt_ops; - jz4740_wdt->timeout = heartbeat; jz4740_wdt->min_timeout = 1; - jz4740_wdt->max_timeout = MAX_HEARTBEAT; + jz4740_wdt->max_timeout = 0xffff / rate; + jz4740_wdt->timeout = clamp(heartbeat, + jz4740_wdt->min_timeout, + jz4740_wdt->max_timeout); jz4740_wdt->parent = dev; watchdog_set_nowayout(jz4740_wdt, nowayout); watchdog_set_drvdata(jz4740_wdt, drvdata); @@ -186,12 +177,6 @@ static int jz4740_wdt_probe(struct platform_device *pdev) if (IS_ERR(drvdata->base)) return PTR_ERR(drvdata->base); - drvdata->rtc_clk = devm_clk_get(dev, "rtc"); - if (IS_ERR(drvdata->rtc_clk)) { - dev_err(dev, "cannot find RTC clock\n"); - return PTR_ERR(drvdata->rtc_clk); - } - return devm_watchdog_register_device(dev, &drvdata->wdt); }