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Date: Mon, 30 Jun 2014 19:05:47 +0200
From: Tomasz Figa <t.figa@...sung.com>
To: Pankaj Dubey <pankaj.dubey@...sung.com>,
linux-arm-kernel@...ts.infradead.org,
linux-samsung-soc@...r.kernel.org, linux-kernel@...r.kernel.org
Cc: kgene.kim@...sung.com, linux@....linux.org.uk,
vikas.sajjan@...sung.com, joshi@...sung.com, naushad@...sung.com,
thomas.ab@...sung.com, chow.kim@...sung.com
Subject: Re: [PATCH v5 4/5] ARM: EXYNOS: Add platform driver support for Exynos
PMU
Hi Pankaj,
Please see my comments inline.
On 25.06.2014 16:03, Pankaj Dubey wrote:
> This patch modifies Exynos Power Management Unit (PMU) initialization
> implementation in following way:
>
> - Added platform driver support and probe function where Exynos PMU
> driver will register itself as syscon provider with syscon framework.
> - Added platform struct exynos_pmu_data to hold platform specific data.
> - For each SoC's PMU support now we can add platform data and statically
> bind PMU configuration and SoC specific initialization function.
> - Separate each SoC's PMU initialization function and make it as part of
> platform data.
> - It also removes uses of soc_is_exynosXYZ().
[snip]
> @@ -93,7 +112,7 @@ static const struct exynos_pmu_conf exynos4210_pmu_config[] = {
> { PMU_TABLE_END,},
> };
>
> -static const struct exynos_pmu_conf exynos4x12_pmu_config[] = {
> +static const struct exynos_pmu_conf exynos4212_pmu_config[] = {
Why the name change?
> { S5P_ARM_CORE0_LOWPWR, { 0x0, 0x0, 0x2 } },
> { S5P_DIS_IRQ_CORE0, { 0x0, 0x0, 0x0 } },
> { S5P_DIS_IRQ_CENTRAL0, { 0x0, 0x0, 0x0 } },
> @@ -335,7 +354,7 @@ static unsigned int const exynos5_list_diable_wfi_wfe[] = {
> EXYNOS5_ISP_ARM_OPTION,
> };
>
> -static void exynos5_init_pmu(void)
> +static void exynos5_powerdown_conf(enum sys_powerdown mode)
> {
> unsigned int i;
> unsigned int tmp;
> @@ -372,51 +391,151 @@ void exynos_sys_powerdown_conf(enum sys_powerdown mode)
> {
> unsigned int i;
>
> - if (soc_is_exynos5250())
> - exynos5_init_pmu();
> + struct exynos_pmu_data *pmu_data = pmu_context->pmu_data;
> +
> + if (!pmu_data)
> + return;
>
> - for (i = 0; (exynos_pmu_config[i].offset != PMU_TABLE_END) ; i++)
> - __raw_writel(exynos_pmu_config[i].val[mode],
> - pmu_base_addr + exynos_pmu_config[i].offset);
> + if (pmu_data->powerdown_conf)
> + pmu_data->powerdown_conf(mode);
>
> - if (soc_is_exynos4412()) {
> - for (i = 0; exynos4412_pmu_config[i].offset != PMU_TABLE_END ; i++)
> - __raw_writel(exynos4412_pmu_config[i].val[mode],
> - pmu_base_addr + exynos4412_pmu_config[i].offset);
> + if (pmu_data->pmu_config) {
> + for (i = 0; (pmu_data->pmu_config[i].offset != PMU_TABLE_END) ; i++)
> + __raw_writel(pmu_data->pmu_config[i].val[mode],
> + pmu_base_addr + pmu_data->pmu_config[i].offset);
Analogically to patch 2/5, you could add static inline accessors and use
them instead of adding pmu_base_addr every time.
> + }
> +
> + if (pmu_data->pmu_config_extra) {
> + for (i = 0; pmu_data->pmu_config_extra[i].offset != PMU_TABLE_END; i++)
> + __raw_writel(pmu_data->pmu_config_extra[i].val[mode],
> + pmu_base_addr + pmu_data->pmu_config_extra[i].offset);
> }
> }
>
> -static int __init exynos_pmu_init(void)
> +static void exynos5250_pmu_init(void)
> {
> unsigned int value;
> + /*
> + * When SYS_WDTRESET is set, watchdog timer reset request
> + * is ignored by power management unit.
> + */
> + value = __raw_readl(pmu_base_addr + EXYNOS5_AUTO_WDTRESET_DISABLE);
> + value &= ~EXYNOS5_SYS_WDTRESET;
> + __raw_writel(value, pmu_base_addr + EXYNOS5_AUTO_WDTRESET_DISABLE);
> +
> + value = __raw_readl(pmu_base_addr + EXYNOS5_MASK_WDTRESET_REQUEST);
> + value &= ~EXYNOS5_SYS_WDTRESET;
> + __raw_writel(value, pmu_base_addr + EXYNOS5_MASK_WDTRESET_REQUEST);
> +}
> +
> +static struct exynos_pmu_data exynos4210_pmu_data = {
static const struct
> + .pmu_config = exynos4210_pmu_config,
> +};
> +
> +static struct exynos_pmu_data exynos4212_pmu_data = {
static const struct
> + .pmu_config = exynos4212_pmu_config,
> +};
> +
> +static struct exynos_pmu_data exynos4412_pmu_data = {
static const struct
> + .pmu_config = exynos4212_pmu_config,
> + .pmu_config_extra = exynos4412_pmu_config,
> +};
> +
> +static struct exynos_pmu_data exynos5250_pmu_data = {
static const struct
> + .pmu_config = exynos5250_pmu_config,
> + .pmu_init = exynos5250_pmu_init,
> + .powerdown_conf = exynos5_powerdown_conf,
> +};
>
> - exynos_pmu_config = exynos4210_pmu_config;
> -
> - if (soc_is_exynos4210()) {
> - exynos_pmu_config = exynos4210_pmu_config;
> - pr_info("EXYNOS4210 PMU Initialize\n");
> - } else if (soc_is_exynos4212() || soc_is_exynos4412()) {
> - exynos_pmu_config = exynos4x12_pmu_config;
> - pr_info("EXYNOS4x12 PMU Initialize\n");
> - } else if (soc_is_exynos5250()) {
> - /*
> - * When SYS_WDTRESET is set, watchdog timer reset request
> - * is ignored by power management unit.
> - */
> - value = __raw_readl(pmu_base_addr + EXYNOS5_AUTO_WDTRESET_DISABLE);
> - value &= ~EXYNOS5_SYS_WDTRESET;
> - __raw_writel(value, pmu_base_addr + EXYNOS5_AUTO_WDTRESET_DISABLE);
> -
> - value = __raw_readl(pmu_base_addr + EXYNOS5_MASK_WDTRESET_REQUEST);
> - value &= ~EXYNOS5_SYS_WDTRESET;
> - __raw_writel(value, pmu_base_addr + EXYNOS5_MASK_WDTRESET_REQUEST);
> -
> - exynos_pmu_config = exynos5250_pmu_config;
> - pr_info("EXYNOS5250 PMU Initialize\n");
> - } else {
> - pr_info("EXYNOS: PMU not supported\n");
> +static struct regmap_config pmu_regmap_config = {
static const struct
> + .reg_bits = 32,
> + .val_bits = 32,
> + .reg_stride = 4,
> +};
> +
> +/*
> + * PMU platform driver and devicetree bindings.
> + */
> +static struct of_device_id exynos_pmu_of_device_ids[] = {
static const struct
> + {
> + .compatible = "samsung,exynos4210-pmu",
> + .data = (void *)&exynos4210_pmu_data,
No need for the cast.
> + },
> + {
nit: You could place both parentheses in the same line, i.e.
}, {
> + .compatible = "samsung,exynos4212-pmu",
> + .data = (void *)&exynos4212_pmu_data,
Ditto.
> + },
> + {
> + .compatible = "samsung,exynos4412-pmu",
> + .data = (void *)&exynos4412_pmu_data,
Ditto.
> + },
> + {
> + .compatible = "samsung,exynos5250-pmu",
> + .data = (void *)&exynos5250_pmu_data,
Ditto.
> + },
> + {},
It is a good practice to put a comment inside the sentinel, e.g.
{ /* sentinel */ }
> +};
> +
> +static int exynos_pmu_probe(struct platform_device *pdev)
> +{
> + const struct of_device_id *match;
> + struct device *dev = &pdev->dev;
> + struct regmap *regmap;
> + struct resource *res;
> +
> + res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> + if (!res)
> + return -ENOENT;
No need to check this here, if you use devm_ioremap_resource() instead.
> +
> + pmu_base_addr = devm_ioremap(dev, res->start, resource_size(res));
You could use devm_ioremap_resource() instead. In addition to handling
the resource directly without the need to access its internals here, it
also checks the validity of the resource pointer.
> + if (IS_ERR(pmu_base_addr))
> + return PTR_ERR(pmu_base_addr);
> +
> + pmu_context = devm_kzalloc(&pdev->dev,
> + sizeof(struct exynos_pmu_context),
> + GFP_KERNEL);
> +
> + if (pmu_context == NULL) {
nit: Extraneous blank line.
nit: Inconsistent pointer check (!res above, but == NULL here), just use
!ptr everywhere, please.
> + dev_err(dev, "Cannot allocate memory.\n");
> + return -ENOMEM;
> + }
> +
> + regmap = devm_regmap_init_mmio(dev, pmu_base_addr,
> + &pmu_regmap_config);
> + if (IS_ERR(regmap)) {
> + dev_err(dev, "regmap init failed\n");
> + return PTR_ERR(regmap);
> }
>
> + devm_syscon_register(dev, regmap);
> +
> + match = of_match_node(exynos_pmu_of_device_ids, pdev->dev.of_node);
> +
> + pmu_context->pmu_data = (struct exynos_pmu_data *) match->data;
No need to cast if you change all affected pointers to const.
> +
> + if (pmu_context->pmu_data && pmu_context->pmu_data->pmu_init)
In what conditions pmu_data will be NULL?
> + pmu_context->pmu_data->pmu_init();
> +
> + pmu_context->dev = dev;
I believe this should be set before calling pmu_init().
> +
> + platform_set_drvdata(pdev, pmu_context);
> +
> + pr_info("Exynos PMU Driver probe done!!!\n");
Hurrah, the driver probed! The users won't care, though, and they might
find those exclamation marks scary. ;)
dev_dbg() without those exclamation marks would be more appropriate.
Best regards,
Tomasz
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