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Subject: Re: [PATCH V2 1/3] watchdog: stm32: add pclk feature for stm32mp1
To:     Guenter Roeck <linux@roeck-us.net>,
        Wim Van Sebroeck <wim@linux-watchdog.org>,
        Rob Herring <robh+dt@kernel.org>
CC:     Maxime Coquelin <mcoquelin.stm32@gmail.com>,
        Alexandre Torgue <alexandre.torgue@st.com>,
        <linux-watchdog@vger.kernel.org>,
        <linux-arm-kernel@lists.infradead.org>,
        <linux-kernel@vger.kernel.org>, <devicetree@vger.kernel.org>
References: <1529481238-15277-1-git-send-email-ludovic.Barre@st.com>
 <1529481238-15277-2-git-send-email-ludovic.Barre@st.com>
 <6162d701-2afd-5a22-d38f-7fb9e726cff7@roeck-us.net>
From:   Ludovic BARRE <ludovic.barre@st.com>
Message-ID: <e9babb86-7588-5de6-93ab-4cdd8982e773@st.com>
Date:   Wed, 20 Jun 2018 15:24:07 +0200
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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
...
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);
>>
>