Re: [PATCH V3 1/4] cpufreq: exynos: Adding cpufreq driver for exynos5440

[Sylwester Nawrocki <s.nawrocki@samsung.com>]

On 03/07/2013 05:13 AM, Amit Daniel Kachhap wrote:
> +/* Register definations */

s/definations/definitions

> +#define XMU_DVFS_CTRL		0x0060
> +#define XMU_PMU_P0_7		0x0064
> +#define XMU_C0_3_PSTATE		0x0090
> +#define XMU_P_LIMIT		0x00A0
> +#define XMU_P_STATUS		0x00A4
> +#define XMU_PMUEVTEN		0x00D0
> +#define XMU_PMUIRQEN		0x00D4
> +#define XMU_PMUIRQ		0x00D8

Keeping all hex numbers lower case might be a good idea.

> +
> +/* PMU mask and shift definations */
> +#define P_VALUE_MASK		0x7
> +
> +#define XMU_DVFS_CTRL_EN_SHIFT	0
> +
> +#define P0_7_CPUCLKDEV_SHIFT	21
> +#define P0_7_CPUCLKDEV_MASK	0x7
> +#define P0_7_ATBCLKDEV_SHIFT	18
> +#define P0_7_ATBCLKDEV_MASK	0x7
> +#define P0_7_CSCLKDEV_SHIFT	15
> +#define P0_7_CSCLKDEV_MASK	0x7
> +#define P0_7_CPUEMA_SHIFT	28
> +#define P0_7_CPUEMA_MASK	0xf
> +#define P0_7_L2EMA_SHIFT	24
> +#define P0_7_L2EMA_MASK	0xf
...
> +static int exynos_cpufreq_probe(struct platform_device *pdev)
> +{
> +	int ret = -EINVAL;
> +	struct device_node *np;
> +	struct resource res;
> +
> +	np =  of_find_compatible_node(NULL, NULL, "samsung,exynos5440-cpufreq");
> +	if (!np)
> +		return -ENODEV;
> +
> +	dvfs_info = devm_kzalloc(&pdev->dev, sizeof(*dvfs_info), GFP_KERNEL);
> +	if (!dvfs_info) {
> +		ret = -ENOMEM;
> +		goto err_put_node;
> +	}
> +
> +	dvfs_info->dev = &pdev->dev;
> +	dvfs_info->dev->of_node = np;
> +
> +	ret = of_address_to_resource(np, 0, &res);
> +	if (ret)
> +		goto err_put_node;
> +
> +	dvfs_info->base = devm_ioremap(dvfs_info->dev, res.start,

There is a devm_ioremap_resource() function that has been introduced
recently. It could simplify this code a bit and is preferred over
devm_ioremap().

> +					resource_size(&res));
> +	if (!dvfs_info->base) {
> +		pr_err("No cpufreq memory map found\n");
> +		ret = -ENODEV;
> +		goto err_put_node;
> +	}
> +
> +	dvfs_info->irq = irq_of_parse_and_map(np, 0);
> +	if (dvfs_info->irq == 0) {
> +		pr_err("No cpufreq irq found\n");

Wouldn't dev_err() be more appropriate here ?

> +		ret = -ENODEV;
> +		goto err_put_node;
> +	}
> +
> +	ret = of_init_opp_table(dvfs_info->dev);
> +	if (ret) {
> +		pr_err("failed to init OPP table: %d\n", ret);
> +		goto err_put_node;
> +	}
> +
> +	ret = opp_init_cpufreq_table(dvfs_info->dev, &dvfs_info->freq_table);
> +	if (ret) {
> +		pr_err("failed to init cpufreq table: %d\n", ret);
> +		goto err_put_node;
> +	}
> +	dvfs_info->freq_count = opp_get_opp_count(dvfs_info->dev);
> +	exynos_sort_descend_freq_table();
> +
> +	if (of_property_read_u32(np, "clock-latency", &dvfs_info->latency))
> +		dvfs_info->latency = DEF_TRANS_LATENCY;
> +
> +	dvfs_info->cpu_clk = devm_clk_get(dvfs_info->dev, "armclk");
> +	if (IS_ERR_OR_NULL(dvfs_info->cpu_clk)) {

devm_clk_get() return value needs to be checked with IS_ERR(),
not IS_ERR_OR_NULL().

> +		pr_err("Failed to get cpu clock\n");
> +		ret = PTR_ERR(dvfs_info->cpu_clk);
> +		goto err_free_table;
> +	}
> +
> +	dvfs_info->cur_frequency = clk_get_rate(dvfs_info->cpu_clk);
> +	if (!dvfs_info->cur_frequency) {
> +		pr_err("Failed to get clock rate\n");
> +		ret = -EINVAL;
> +		goto err_free_table;
> +	}
> +	dvfs_info->cur_frequency /= 1000;
> +
> +	INIT_WORK(&dvfs_info->irq_work, exynos_cpufreq_work);
> +	if (devm_request_irq(dvfs_info->dev, dvfs_info->irq, exynos_cpufreq_irq,
> +				IRQF_TRIGGER_NONE, CPUFREQ_NAME, dvfs_info)) {
> +		pr_err("Failed to register IRQ\n");
> +		ret = -ENODEV;
> +		goto err_free_table;
> +	}
> +
> +	ret = init_div_table();
> +	if (ret) {
> +		pr_err("Failed to initialise div table\n");
> +		goto err_free_table;
> +	}
> +
> +	exynos_enable_dvfs();
> +	ret = cpufreq_register_driver(&exynos_driver);
> +	if (ret) {
> +		pr_err("%s: failed to register cpufreq driver\n", __func__);
> +		goto err_free_table;
> +	}
> +
> +	of_node_put(np);
> +	dvfs_info->dvfs_enable = true;
> +	pr_info("exynos5440 DVFS initialized.\n");

dev_info() ?

> +	return 0;
> +
> +err_free_table:
> +	opp_free_cpufreq_table(dvfs_info->dev, &dvfs_info->freq_table);
> +err_put_node:
> +	of_node_put(np);
> +	pr_err("%s: failed initialization\n", __func__);

Is this really needed ? This failure will be logged by the driver core
anyway.

> +	return ret;
> +