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Message-ID: <6162d701-2afd-5a22-d38f-7fb9e726cff7@roeck-us.net>
Date: Wed, 20 Jun 2018 02:19:41 -0700
From: Guenter Roeck <linux@...ck-us.net>
To: Ludovic Barre <ludovic.Barre@...com>,
Wim Van Sebroeck <wim@...ux-watchdog.org>,
Rob Herring <robh+dt@...nel.org>
Cc: Maxime Coquelin <mcoquelin.stm32@...il.com>,
Alexandre Torgue <alexandre.torgue@...com>,
linux-watchdog@...r.kernel.org,
linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org,
devicetree@...r.kernel.org
Subject: Re: [PATCH V2 1/3] watchdog: stm32: add pclk feature for stm32mp1
On 06/20/2018 12:53 AM, Ludovic Barre wrote:
> From: Ludovic Barre <ludovic.barre@...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@...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@...03000 {
> compatible = "st,stm32-iwdg";
> reg = <0x40003000 0x400>;
> clocks = <&clk_lsi>;
> + clock-names = "lsi";
> + timeout-sec = <32>;
> +};
> +
> +iwdg: iwdg@...02000 {
> + 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 ...
> 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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