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

[Guenter Roeck <linux@roeck-us.net>]

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@st.com>
>>>
>>> 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@st.com>
>>> ---
>>>   .../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

> 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);
>>>
>>
>