From 9c28d6df7534e1b64d485fde02ebe62375ea9bcc Mon Sep 17 00:00:00 2001 From: Miquel Raynal Date: Thu, 26 Apr 2018 15:42:17 +0530 Subject: cpufreq: add suspend/resume support in Armada 37xx DVFS driver Add suspend/resume hooks in Armada 37xx DVFS driver to handle S2RAM operations. As there is currently no 'driver' structure, create one to store both the regmap and the register values during suspend operation. Signed-off-by: Miquel Raynal Signed-off-by: Viresh Kumar Tested-by: Gregory CLEMENT Signed-off-by: Rafael J. Wysocki --- drivers/cpufreq/armada-37xx-cpufreq.c | 67 +++++++++++++++++++++++++++++++++-- 1 file changed, 65 insertions(+), 2 deletions(-) diff --git a/drivers/cpufreq/armada-37xx-cpufreq.c b/drivers/cpufreq/armada-37xx-cpufreq.c index 1d5db6f6ace9..739da90ff3f6 100644 --- a/drivers/cpufreq/armada-37xx-cpufreq.c +++ b/drivers/cpufreq/armada-37xx-cpufreq.c @@ -23,6 +23,8 @@ #include #include +#include "cpufreq-dt.h" + /* Power management in North Bridge register set */ #define ARMADA_37XX_NB_L0L1 0x18 #define ARMADA_37XX_NB_L2L3 0x1C @@ -56,6 +58,16 @@ */ #define LOAD_LEVEL_NR 4 +struct armada37xx_cpufreq_state { + struct regmap *regmap; + u32 nb_l0l1; + u32 nb_l2l3; + u32 nb_dyn_mod; + u32 nb_cpu_load; +}; + +static struct armada37xx_cpufreq_state *armada37xx_cpufreq_state; + struct armada_37xx_dvfs { u32 cpu_freq_max; u8 divider[LOAD_LEVEL_NR]; @@ -136,7 +148,7 @@ static void __init armada37xx_cpufreq_dvfs_setup(struct regmap *base, clk_set_parent(clk, parent); } -static void __init armada37xx_cpufreq_disable_dvfs(struct regmap *base) +static void armada37xx_cpufreq_disable_dvfs(struct regmap *base) { unsigned int reg = ARMADA_37XX_NB_DYN_MOD, mask = ARMADA_37XX_NB_DFS_EN; @@ -162,8 +174,44 @@ static void __init armada37xx_cpufreq_enable_dvfs(struct regmap *base) regmap_update_bits(base, reg, mask, mask); } +static int armada37xx_cpufreq_suspend(struct cpufreq_policy *policy) +{ + struct armada37xx_cpufreq_state *state = armada37xx_cpufreq_state; + + regmap_read(state->regmap, ARMADA_37XX_NB_L0L1, &state->nb_l0l1); + regmap_read(state->regmap, ARMADA_37XX_NB_L2L3, &state->nb_l2l3); + regmap_read(state->regmap, ARMADA_37XX_NB_CPU_LOAD, + &state->nb_cpu_load); + regmap_read(state->regmap, ARMADA_37XX_NB_DYN_MOD, &state->nb_dyn_mod); + + return 0; +} + +static int armada37xx_cpufreq_resume(struct cpufreq_policy *policy) +{ + struct armada37xx_cpufreq_state *state = armada37xx_cpufreq_state; + + /* Ensure DVFS is disabled otherwise the following registers are RO */ + armada37xx_cpufreq_disable_dvfs(state->regmap); + + regmap_write(state->regmap, ARMADA_37XX_NB_L0L1, state->nb_l0l1); + regmap_write(state->regmap, ARMADA_37XX_NB_L2L3, state->nb_l2l3); + regmap_write(state->regmap, ARMADA_37XX_NB_CPU_LOAD, + state->nb_cpu_load); + + /* + * NB_DYN_MOD register is the one that actually enable back DVFS if it + * was enabled before the suspend operation. This must be done last + * otherwise other registers are not writable. + */ + regmap_write(state->regmap, ARMADA_37XX_NB_DYN_MOD, state->nb_dyn_mod); + + return 0; +} + static int __init armada37xx_cpufreq_driver_init(void) { + struct cpufreq_dt_platform_data pdata; struct armada_37xx_dvfs *dvfs; struct platform_device *pdev; unsigned long freq; @@ -213,6 +261,15 @@ static int __init armada37xx_cpufreq_driver_init(void) return -EINVAL; } + armada37xx_cpufreq_state = kmalloc(sizeof(*armada37xx_cpufreq_state), + GFP_KERNEL); + if (!armada37xx_cpufreq_state) { + clk_put(clk); + return -ENOMEM; + } + + armada37xx_cpufreq_state->regmap = nb_pm_base; + armada37xx_cpufreq_dvfs_setup(nb_pm_base, clk, dvfs->divider); clk_put(clk); @@ -228,7 +285,11 @@ static int __init armada37xx_cpufreq_driver_init(void) /* 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); + pdata.suspend = armada37xx_cpufreq_suspend; + pdata.resume = armada37xx_cpufreq_resume; + + pdev = platform_device_register_data(NULL, "cpufreq-dt", -1, &pdata, + sizeof(pdata)); ret = PTR_ERR_OR_ZERO(pdev); if (ret) goto disable_dvfs; @@ -244,6 +305,8 @@ remove_opp: dev_pm_opp_remove(cpu_dev, freq); } + kfree(armada37xx_cpufreq_state); + return ret; } /* late_initcall, to guarantee the driver is loaded after A37xx clock driver */ -- cgit v1.2.3