Re: [PATCH V2 1/3] watchdog: stm32: add pclk feature for stm32mp1

[Ludovic BARRE <ludovic.barre@xxxxxx>]

On 06/20/2018 03:29 PM, Guenter Roeck wrote:
> On 06/20/2018 06:24 AM, Ludovic BARRE wrote:
> > On 06/20/2018 11:19 AM, Guenter Roeck wrote:
> > > On 06/20/2018 12:53 AM, Ludovic Barre wrote:
> > > > From: Ludovic Barre <ludovic.barre@xxxxxx>
> > > >
> > > > This patch adds config data to manage specific properties by
> > > > compatible. Adds stm32mp1 config which requires pclk clock.
> > > >
> > > > Signed-off-by: Ludovic Barre <ludovic.barre@xxxxxx>
> > > > ---
> > > >   .../devicetree/bindings/watchdog/st,stm32-iwdg.txt |  21 +++-
> > > >   drivers/watchdog/stm32_iwdg.c                      | 132 
> > > > ++++++++++++++-------
> > > >   2 files changed, 104 insertions(+), 49 deletions(-)
> > > >
> > > > diff --git 
> > > > a/Documentation/devicetree/bindings/watchdog/st,stm32-iwdg.txt 
> > > > b/Documentation/devicetree/bindings/watchdog/st,stm32-iwdg.txt
> > > > index cc13b10a..f07f6d89 100644
> > > > --- a/Documentation/devicetree/bindings/watchdog/st,stm32-iwdg.txt
> > > > +++ b/Documentation/devicetree/bindings/watchdog/st,stm32-iwdg.txt
> > > > @@ -2,18 +2,31 @@ STM32 Independent WatchDoG (IWDG)
> > > >   ---------------------------------
> > > >   Required properties:
> > > > -- compatible: "st,stm32-iwdg"
> > > > -- reg: physical base address and length of the registers set for 
> > > > the device
> > > > -- clocks: must contain a single entry describing the clock input
> > > > +- compatible: Should be either "st,stm32-iwdg" or "st,stm32mp1-iwdg"
> > > > +- reg: Physical base address and length of the registers set for 
> > > > the device
> > > > +- clocks: Reference to the clock entry lsi. Additional pclk clock 
> > > > entry
> > > > +  is required only for st,stm32mp1-iwdg.
> > > > +- clock-names: Name of the clocks used.
> > > > +  "lsi" for st,stm32-iwdg
> > > > +  "pclk", "lsi" for st,stm32mp1-iwdg
> > > >   Optional Properties:
> > > >   - timeout-sec: Watchdog timeout value in seconds.
> > > > -Example:
> > > > +Examples:
> > > >   iwdg: watchdog@40003000 {
> > > >       compatible = "st,stm32-iwdg";
> > > >       reg = <0x40003000 0x400>;
> > > >       clocks = <&clk_lsi>;
> > > > +    clock-names = "lsi";
> > > > +    timeout-sec = <32>;
> > > > +};
> > > > +
> > > > +iwdg: iwdg@5a002000 {
> > > > +    compatible = "st,stm32mp1-iwdg";
> > > > +    reg = <0x5a002000 0x400>;
> > > > +    clocks = <&rcc IWDG2>, <&clk_lsi>;
> > > > +    clock-names = "pclk", "lsi";
> > > >       timeout-sec = <32>;
> > > >   };
> > > > diff --git a/drivers/watchdog/stm32_iwdg.c 
> > > > b/drivers/watchdog/stm32_iwdg.c
> > > > index c97ad56..fc96670 100644
> > > > --- a/drivers/watchdog/stm32_iwdg.c
> > > > +++ b/drivers/watchdog/stm32_iwdg.c
> > > > @@ -11,12 +11,13 @@
> > > >   #include <linux/clk.h>
> > > >   #include <linux/delay.h>
> > > > -#include <linux/kernel.h>
> > > > -#include <linux/module.h>
> > > >   #include <linux/interrupt.h>
> > > >   #include <linux/io.h>
> > > >   #include <linux/iopoll.h>
> > > > +#include <linux/kernel.h>
> > > > +#include <linux/module.h>
> > > >   #include <linux/of.h>
> > > > +#include <linux/of_device.h>
> > > >   #include <linux/platform_device.h>
> > > >   #include <linux/watchdog.h>
> > > > @@ -54,11 +55,17 @@
> > > >   #define TIMEOUT_US    100000
> > > >   #define SLEEP_US    1000
> > > > +struct stm32_iwdg_config {
> > > > +    bool has_pclk;
> > > > +};
> > > > +
> > >
> > > This data structure is unnecessary. Just assign the boolean directly 
> > > to .data
> > > and ...
> >
> > Ok, I send a v3, with boolean directly to .data
> > like:
> >
> > #define NO_PCLK        false
> > #define HAS_PCLK    true
> > ...
>
> Just use true/false directly. There is no need for those defines.
>
> If you want the reader to understand what is defined, I would be ok with
>
> #define HAS_PCLK    true
>
> static const struct of_device_id stm32_iwdg_of_match[] = {
>       { .compatible = "st,stm32-iwdg", .data = (void *) !HAS_PCLK },
>       { .compatible = "st,stm32mp1-iwdg", .data = (void *) HAS_PCLK },
>       { /* end node */ }
>
> Guenter

Ok, thanks

> > static const struct of_device_id stm32_iwdg_of_match[] = {
> >      { .compatible = "st,stm32-iwdg", .data = (void *) NO_PCLK },
> >      { .compatible = "st,stm32mp1-iwdg", .data = (void *) HAS_PCLK },
> >      { /* end node */ }
> > };
> >
> > Note:
> > V3, because I sent my original version with V2
> > (it's mistake)
> >
> > > >   struct stm32_iwdg {
> > > > -    struct watchdog_device    wdd;
> > > > -    void __iomem        *regs;
> > > > -    struct clk        *clk;
> > > > -    unsigned int        rate;
> > > > +    struct watchdog_device        wdd;
> > > > +    void __iomem            *regs;
> > > > +    struct stm32_iwdg_config    *config;
> > >
> > > declare bool has_pclk here.
> > >
> > > > +    struct clk            *clk_lsi;
> > > > +    struct clk            *clk_pclk;
> > > > +    unsigned int            rate;
> > > >   };
> > > >   static inline u32 reg_read(void __iomem *base, u32 reg)
> > > > @@ -133,6 +140,44 @@ static int stm32_iwdg_set_timeout(struct 
> > > > watchdog_device *wdd,
> > > >       return 0;
> > > >   }
> > > > +static int stm32_iwdg_clk_init(struct platform_device *pdev,
> > > > +                   struct stm32_iwdg *wdt)
> > > > +{
> > > > +    u32 ret;
> > > > +
> > > > +    wdt->clk_lsi = devm_clk_get(&pdev->dev, "lsi");
> > > > +    if (IS_ERR(wdt->clk_lsi)) {
> > > > +        dev_err(&pdev->dev, "Unable to get lsi clock\n");
> > > > +        return PTR_ERR(wdt->clk_lsi);
> > > > +    }
> > > > +
> > > > +    /* optional peripheral clock */
> > > > +    if (wdt->config->has_pclk) {
> > > > +        wdt->clk_pclk = devm_clk_get(&pdev->dev, "pclk");
> > > > +        if (IS_ERR(wdt->clk_pclk)) {
> > > > +            dev_err(&pdev->dev, "Unable to get pclk clock\n");
> > > > +            return PTR_ERR(wdt->clk_pclk);
> > > > +        }
> > > > +
> > > > +        ret = clk_prepare_enable(wdt->clk_pclk);
> > > > +        if (ret) {
> > > > +            dev_err(&pdev->dev, "Unable to prepare pclk clock\n");
> > > > +            return ret;
> > > > +        }
> > > > +    }
> > > > +
> > > > +    ret = clk_prepare_enable(wdt->clk_lsi);
> > > > +    if (ret) {
> > > > +        dev_err(&pdev->dev, "Unable to prepare lsi clock\n");
> > > > +        clk_disable_unprepare(wdt->clk_pclk);
> > > > +        return ret;
> > > > +    }
> > > > +
> > > > +    wdt->rate = clk_get_rate(wdt->clk_lsi);
> > > > +
> > > > +    return 0;
> > > > +}
> > > > +
> > > >   static const struct watchdog_info stm32_iwdg_info = {
> > > >       .options    = WDIOF_SETTIMEOUT |
> > > >                 WDIOF_MAGICCLOSE |
> > > > @@ -147,49 +192,50 @@ static const struct watchdog_ops 
> > > > stm32_iwdg_ops = {
> > > >       .set_timeout    = stm32_iwdg_set_timeout,
> > > >   };
> > > > +static const struct stm32_iwdg_config stm32_iwdg_cfg = {
> > > > +    .has_pclk = false,
> > > > +};
> > > > +
> > > > +static const struct stm32_iwdg_config stm32mp1_iwdg_cfg = {
> > > > +    .has_pclk = true,
> > > > +};
> > > > +
> > > > +static const struct of_device_id stm32_iwdg_of_match[] = {
> > > > +    { .compatible = "st,stm32-iwdg", .data = &stm32_iwdg_cfg },
> > > > +    { .compatible = "st,stm32mp1-iwdg", .data = &stm32mp1_iwdg_cfg },
> > > > +    { /* end node */ }
> > > > +};
> > > > +MODULE_DEVICE_TABLE(of, stm32_iwdg_of_match);
> > > > +
> > > >   static int stm32_iwdg_probe(struct platform_device *pdev)
> > > >   {
> > > >       struct watchdog_device *wdd;
> > > > +    const struct of_device_id *match;
> > > >       struct stm32_iwdg *wdt;
> > > >       struct resource *res;
> > > > -    void __iomem *regs;
> > > > -    struct clk *clk;
> > > >       int ret;
> > > > +    match = of_match_device(stm32_iwdg_of_match, &pdev->dev);
> > > > +    if (!match || !match->data)
> > > > +        return -ENODEV;
> > > > +
> > > > +    wdt = devm_kzalloc(&pdev->dev, sizeof(*wdt), GFP_KERNEL);
> > > > +    if (!wdt)
> > > > +        return -ENOMEM;
> > > > +
> > > > +    wdt->config = (struct stm32_iwdg_config *)match->data;
> > > > +
> > > >       /* This is the timer base. */
> > > >       res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> > > > -    regs = devm_ioremap_resource(&pdev->dev, res);
> > > > -    if (IS_ERR(regs)) {
> > > > +    wdt->regs = devm_ioremap_resource(&pdev->dev, res);
> > > > +    if (IS_ERR(wdt->regs)) {
> > > >           dev_err(&pdev->dev, "Could not get resource\n");
> > > > -        return PTR_ERR(regs);
> > > > +        return PTR_ERR(wdt->regs);
> > > >       }
> > > > -    clk = devm_clk_get(&pdev->dev, NULL);
> > > > -    if (IS_ERR(clk)) {
> > > > -        dev_err(&pdev->dev, "Unable to get clock\n");
> > > > -        return PTR_ERR(clk);
> > > > -    }
> > > > -
> > > > -    ret = clk_prepare_enable(clk);
> > > > -    if (ret) {
> > > > -        dev_err(&pdev->dev, "Unable to prepare clock %p\n", clk);
> > > > +    ret = stm32_iwdg_clk_init(pdev, wdt);
> > > > +    if (ret)
> > > >           return ret;
> > > > -    }
> > > > -
> > > > -    /*
> > > > -     * Allocate our watchdog driver data, which has the
> > > > -     * struct watchdog_device nested within it.
> > > > -     */
> > > > -    wdt = devm_kzalloc(&pdev->dev, sizeof(*wdt), GFP_KERNEL);
> > > > -    if (!wdt) {
> > > > -        ret = -ENOMEM;
> > > > -        goto err;
> > > > -    }
> > > > -
> > > > -    /* Initialize struct stm32_iwdg. */
> > > > -    wdt->regs = regs;
> > > > -    wdt->clk = clk;
> > > > -    wdt->rate = clk_get_rate(clk);
> > > >       /* Initialize struct watchdog_device. */
> > > >       wdd = &wdt->wdd;
> > > > @@ -217,7 +263,8 @@ static int stm32_iwdg_probe(struct 
> > > > platform_device *pdev)
> > > >       return 0;
> > > >   err:
> > > > -    clk_disable_unprepare(clk);
> > > > +    clk_disable_unprepare(wdt->clk_lsi);
> > > > +    clk_disable_unprepare(wdt->clk_pclk);
> > > >       return ret;
> > > >   }
> > > > @@ -227,23 +274,18 @@ static int stm32_iwdg_remove(struct 
> > > > platform_device *pdev)
> > > >       struct stm32_iwdg *wdt = platform_get_drvdata(pdev);
> > > >       watchdog_unregister_device(&wdt->wdd);
> > > > -    clk_disable_unprepare(wdt->clk);
> > > > +    clk_disable_unprepare(wdt->clk_lsi);
> > > > +    clk_disable_unprepare(wdt->clk_pclk);
> > > >       return 0;
> > > >   }
> > > > -static const struct of_device_id stm32_iwdg_of_match[] = {
> > > > -    { .compatible = "st,stm32-iwdg" },
> > > > -    { /* end node */ }
> > > > -};
> > > > -MODULE_DEVICE_TABLE(of, stm32_iwdg_of_match);
> > > > -
> > > >   static struct platform_driver stm32_iwdg_driver = {
> > > >       .probe        = stm32_iwdg_probe,
> > > >       .remove        = stm32_iwdg_remove,
> > > >       .driver = {
> > > >           .name    = "iwdg",
> > > > -        .of_match_table = stm32_iwdg_of_match,
> > > > +        .of_match_table = of_match_ptr(stm32_iwdg_of_match),
> > > >       },
> > > >   };
> > > >   module_platform_driver(stm32_iwdg_driver);
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