[PATCH v3 3/4] cpufreq: Add DVFS support for Armada 37xx
Viresh Kumar
viresh.kumar at linaro.org
Wed Dec 13 19:04:27 PST 2017
I just searched for tabs and spaces in this patch and here are the observations.
On 13-12-17, 18:51, Gregory CLEMENT wrote:
> +/* Power management in North Bridge register set */
> +#define ARMADA_37XX_NB_L0L1 0x18
There is a single space after #define here, which is good.
> +#define ARMADA_37XX_NB_L2L3 0x1C
> +#define ARMADA_37XX_NB_TBG_DIV_OFF 13
But here and at many places below you have two spaces after #define, which isn't
bad but isn't consistent as well.
> +#define ARMADA_37XX_NB_TBG_DIV_MASK 0x7
> +#define ARMADA_37XX_NB_CLK_SEL_OFF 11
> +#define ARMADA_37XX_NB_CLK_SEL_MASK 0x1
> +#define ARMADA_37XX_NB_CLK_SEL_TBG 0x1
You have used space instead of TAB after ARMADA_37XX_NB_CLK_SEL_TBG here, while
everywhere else we have tabs. Maybe its better to be consistent ?
> +#define ARMADA_37XX_NB_TBG_SEL_OFF 9
> +#define ARMADA_37XX_NB_TBG_SEL_MASK 0x3
> +#define ARMADA_37XX_NB_VDD_SEL_OFF 6
> +#define ARMADA_37XX_NB_VDD_SEL_MASK 0x3
> +#define ARMADA_37XX_NB_CONFIG_SHIFT 16
> +#define ARMADA_37XX_NB_DYN_MOD 0x24
> +#define ARMADA_37XX_NB_CLK_SEL_EN BIT(26)
> +#define ARMADA_37XX_NB_TBG_EN BIT(28)
> +#define ARMADA_37XX_NB_DIV_EN BIT(29)
> +#define ARMADA_37XX_NB_VDD_EN BIT(30)
> +#define ARMADA_37XX_NB_DFS_EN BIT(31)
> +#define ARMADA_37XX_NB_CPU_LOAD 0x30
> +#define ARMADA_37XX_NB_CPU_LOAD_MASK 0x3
> +#define ARMADA_37XX_DVFS_LOAD_0 0
> +#define ARMADA_37XX_DVFS_LOAD_1 1
> +#define ARMADA_37XX_DVFS_LOAD_2 2
> +#define ARMADA_37XX_DVFS_LOAD_3 3
> +
> +/*
> + * On Armada 37xx the Power management manages 4 level of CPU load,
> + * each level can be associated with a CPU clock source, a CPU
> + * divider, a VDD level, etc...
> + */
> +#define LOAD_LEVEL_NR 4
> +
> +struct armada_37xx_dvfs {
> + u32 cpu_freq_max;
> + u8 divider[LOAD_LEVEL_NR];
> +};
> +
> +static struct armada_37xx_dvfs armada_37xx_dvfs[] = {
> + {.cpu_freq_max = 1200*1000*1000, .divider = {1, 2, 4, 6} },
> + {.cpu_freq_max = 1000*1000*1000, .divider = {1, 2, 4, 5} },
> + {.cpu_freq_max = 800*1000*1000, .divider = {1, 2, 3, 4} },
> + {.cpu_freq_max = 600*1000*1000, .divider = {2, 4, 5, 6} },
> +};
> +
> +static struct armada_37xx_dvfs *armada_37xx_cpu_freq_info_get(u32 freq)
> +{
> + int i;
> +
> + for (i = 0; i < ARRAY_SIZE(armada_37xx_dvfs); i++) {
> + if (freq == armada_37xx_dvfs[i].cpu_freq_max)
> + return &armada_37xx_dvfs[i];
> + }
> +
> + pr_err("Unsupported CPU frequency %d MHz\n", freq/1000000);
> + return NULL;
> +}
> +
> +/*
> + * Setup the four level managed by the hardware. Once the four level
> + * will be configured then the DVFS will be enabled.
> + */
> +static void __init armada37xx_cpufreq_dvfs_setup(struct regmap *base,
> + struct clk *clk, u8 *divider)
> +{
> + int load_lvl;
> + struct clk *parent;
> +
> + for (load_lvl = 0; load_lvl < LOAD_LEVEL_NR; load_lvl++) {
> + unsigned int reg, mask, val, offset = 0;
double space before "val".
> +
> + if (load_lvl <= ARMADA_37XX_DVFS_LOAD_1)
> + reg = ARMADA_37XX_NB_L0L1;
> + else
> + reg = ARMADA_37XX_NB_L2L3;
> +
> + if (load_lvl == ARMADA_37XX_DVFS_LOAD_0 ||
> + load_lvl == ARMADA_37XX_DVFS_LOAD_2)
double spaces after ==
> + offset += ARMADA_37XX_NB_CONFIG_SHIFT;
> +
> + /* Set cpu clock source, for all the level we use TBG */
> + val = ARMADA_37XX_NB_CLK_SEL_TBG << ARMADA_37XX_NB_CLK_SEL_OFF;
> + mask = (ARMADA_37XX_NB_CLK_SEL_MASK
> + << ARMADA_37XX_NB_CLK_SEL_OFF);
> +
> + /*
> + * Set cpu divider based on the pre-computed array in
> + * order to have balanced step.
> + */
> + val |= divider[load_lvl] << ARMADA_37XX_NB_TBG_DIV_OFF;
> + mask |= (ARMADA_37XX_NB_TBG_DIV_MASK
> + << ARMADA_37XX_NB_TBG_DIV_OFF);
> +
> + /* Set VDD divider which is actually the load level. */
> + val |= load_lvl << ARMADA_37XX_NB_VDD_SEL_OFF;
> + mask |= (ARMADA_37XX_NB_VDD_SEL_MASK
> + << ARMADA_37XX_NB_VDD_SEL_OFF);
> +
> + val <<= offset;
> + mask <<= offset;
> +
> + regmap_update_bits(base, reg, mask, val);
> + }
> +
> + /*
> + * Set cpu clock source, for all the level we keep the same
> + * clock source that the one already configured. For this one
> + * we need to use the clock framework
> + */
> + parent = clk_get_parent(clk);
> + clk_set_parent(clk, parent);
> +}
> +
> +static void __init armada37xx_cpufreq_disable_dvfs(struct regmap *base)
> +{
> + unsigned int reg = ARMADA_37XX_NB_DYN_MOD,
> + mask = ARMADA_37XX_NB_DFS_EN;
> +
> + regmap_update_bits(base, reg, mask, 0);
> +}
> +
> +static void __init armada37xx_cpufreq_enable_dvfs(struct regmap *base)
> +{
> + unsigned int val, reg = ARMADA_37XX_NB_CPU_LOAD,
> + mask = ARMADA_37XX_NB_CPU_LOAD_MASK;
> +
> + /* Start with the highest load (0) */
> + val = ARMADA_37XX_DVFS_LOAD_0;
> + regmap_update_bits(base, reg, mask, val);
> +
> + /* Now enable DVFS for the CPUs */
> + reg = ARMADA_37XX_NB_DYN_MOD;
> + mask = ARMADA_37XX_NB_CLK_SEL_EN | ARMADA_37XX_NB_TBG_EN |
> + ARMADA_37XX_NB_DIV_EN | ARMADA_37XX_NB_VDD_EN |
> + ARMADA_37XX_NB_DFS_EN;
> +
> + regmap_update_bits(base, reg, mask, mask);
> +}
> +
> +static int __init armada37xx_cpufreq_driver_init(void)
> +{
> + struct armada_37xx_dvfs *dvfs;
> + struct platform_device *pdev;
> + unsigned int cur_frequency;
> + struct regmap *nb_pm_base;
> + struct device *cpu_dev;
> + int load_lvl, ret;
> + struct clk *clk;
> +
> + nb_pm_base =
> + syscon_regmap_lookup_by_compatible("marvell,armada-3700-nb-pm");
> +
> + if (IS_ERR(nb_pm_base))
> + return -ENODEV;
> +
> + /* Before doing any configuration on the DVFS first, disable it */
> + armada37xx_cpufreq_disable_dvfs(nb_pm_base);
> +
> + /*
> + * On CPU 0 register the operating points supported (which are
> + * the nominal CPU frequency and full integer divisions of
> + * it).
> + */
> + cpu_dev = get_cpu_device(0);
> + if (!cpu_dev) {
> + dev_err(cpu_dev, "Cannot get CPU\n");
> + return -ENODEV;
> + }
> +
> + clk = clk_get(cpu_dev, 0);
> + if (IS_ERR(clk)) {
> + dev_err(cpu_dev, "Cannot get clock for CPU0\n");
> + return PTR_ERR(clk);
> + }
> +
> + /* Get nominal (current) CPU frequency */
> + cur_frequency = clk_get_rate(clk);
> + if (!cur_frequency) {
> + dev_err(cpu_dev, "Failed to get clock rate for CPU\n");
> + return -EINVAL;
> + }
> +
> + dvfs = armada_37xx_cpu_freq_info_get(cur_frequency);
> + if (!dvfs)
> + return -EINVAL;
> +
> + armada37xx_cpufreq_dvfs_setup(nb_pm_base, clk, dvfs->divider);
> +
> + for (load_lvl = ARMADA_37XX_DVFS_LOAD_0; load_lvl < LOAD_LEVEL_NR;
> + load_lvl++) {
> + unsigned long freq = cur_frequency / dvfs->divider[load_lvl];
> +
> + ret = dev_pm_opp_add(cpu_dev, freq, 0);
> + if (ret) {
> + /* clean-up the already added opp before leaving */
Double space after /*
> + while (load_lvl-- > ARMADA_37XX_DVFS_LOAD_0) {
> + freq = cur_frequency / dvfs->divider[load_lvl];
> + dev_pm_opp_remove(cpu_dev, freq);
> + }
> + return ret;
> + }
> + }
> +
> + /* Now that everything is setup, enable the DVFS at hardware level */
> + armada37xx_cpufreq_enable_dvfs(nb_pm_base);
> +
> + pdev = platform_device_register_simple("cpufreq-dt", -1, NULL, 0);
> +
> + return PTR_ERR_OR_ZERO(pdev);
> +}
> +/* late_initcall, to guarantee the driver is loaded after A37xx clock driver */
> +late_initcall(armada37xx_cpufreq_driver_init);
> +
> +MODULE_AUTHOR("Gregory CLEMENT <gregory.clement at free-electrons.com>");
> +MODULE_DESCRIPTION("Armada 37xx cpufreq driver");
> +MODULE_LICENSE("GPL");
I am not objecting to using double spaces at all these locations, its fine. Just
that I wanted to point it out in case it is not intentional.
--
viresh
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