diff options
Diffstat (limited to 'drivers/iio/adc/stm32-adc-core.c')
| -rw-r--r-- | drivers/iio/adc/stm32-adc-core.c | 194 |
1 files changed, 192 insertions, 2 deletions
diff --git a/drivers/iio/adc/stm32-adc-core.c b/drivers/iio/adc/stm32-adc-core.c index 1f7ce5186dfc..9b85fefc0a96 100644 --- a/drivers/iio/adc/stm32-adc-core.c +++ b/drivers/iio/adc/stm32-adc-core.c @@ -14,9 +14,11 @@ #include <linux/irqchip/chained_irq.h> #include <linux/irqdesc.h> #include <linux/irqdomain.h> +#include <linux/mfd/syscon.h> #include <linux/module.h> #include <linux/of_device.h> #include <linux/pm_runtime.h> +#include <linux/regmap.h> #include <linux/regulator/consumer.h> #include <linux/slab.h> @@ -51,6 +53,17 @@ #define STM32_ADC_CORE_SLEEP_DELAY_MS 2000 +/* SYSCFG registers */ +#define STM32MP1_SYSCFG_PMCSETR 0x04 +#define STM32MP1_SYSCFG_PMCCLRR 0x44 + +/* SYSCFG bit fields */ +#define STM32MP1_SYSCFG_ANASWVDD_MASK BIT(9) + +/* SYSCFG capability flags */ +#define HAS_VBOOSTER BIT(0) +#define HAS_ANASWVDD BIT(1) + /** * stm32_adc_common_regs - stm32 common registers, compatible dependent data * @csr: common status register offset @@ -74,11 +87,13 @@ struct stm32_adc_priv; * @regs: common registers for all instances * @clk_sel: clock selection routine * @max_clk_rate_hz: maximum analog clock rate (Hz, from datasheet) + * @has_syscfg: SYSCFG capability flags */ struct stm32_adc_priv_cfg { const struct stm32_adc_common_regs *regs; int (*clk_sel)(struct platform_device *, struct stm32_adc_priv *); u32 max_clk_rate_hz; + unsigned int has_syscfg; }; /** @@ -87,22 +102,32 @@ struct stm32_adc_priv_cfg { * @domain: irq domain reference * @aclk: clock reference for the analog circuitry * @bclk: bus clock common for all ADCs, depends on part used + * @booster: booster supply reference + * @vdd: vdd supply reference * @vdda: vdda analog supply reference * @vref: regulator reference + * @vdd_uv: vdd supply voltage (microvolts) + * @vdda_uv: vdda supply voltage (microvolts) * @cfg: compatible configuration data * @common: common data for all ADC instances * @ccr_bak: backup CCR in low power mode + * @syscfg: reference to syscon, system control registers */ struct stm32_adc_priv { int irq[STM32_ADC_MAX_ADCS]; struct irq_domain *domain; struct clk *aclk; struct clk *bclk; + struct regulator *booster; + struct regulator *vdd; struct regulator *vdda; struct regulator *vref; + int vdd_uv; + int vdda_uv; const struct stm32_adc_priv_cfg *cfg; struct stm32_adc_common common; u32 ccr_bak; + struct regmap *syscfg; }; static struct stm32_adc_priv *to_stm32_adc_priv(struct stm32_adc_common *com) @@ -349,7 +374,6 @@ static int stm32_adc_irq_probe(struct platform_device *pdev, */ if (i && priv->irq[i] == -ENXIO) continue; - dev_err(&pdev->dev, "failed to get irq\n"); return priv->irq[i]; } @@ -390,6 +414,82 @@ static void stm32_adc_irq_remove(struct platform_device *pdev, } } +static int stm32_adc_core_switches_supply_en(struct stm32_adc_priv *priv, + struct device *dev) +{ + int ret; + + /* + * On STM32H7 and STM32MP1, the ADC inputs are multiplexed with analog + * switches (via PCSEL) which have reduced performances when their + * supply is below 2.7V (vdda by default): + * - Voltage booster can be used, to get full ADC performances + * (increases power consumption). + * - Vdd can be used to supply them, if above 2.7V (STM32MP1 only). + * + * Recommended settings for ANASWVDD and EN_BOOSTER: + * - vdda < 2.7V but vdd > 2.7V: ANASWVDD = 1, EN_BOOSTER = 0 (stm32mp1) + * - vdda < 2.7V and vdd < 2.7V: ANASWVDD = 0, EN_BOOSTER = 1 + * - vdda >= 2.7V: ANASWVDD = 0, EN_BOOSTER = 0 (default) + */ + if (priv->vdda_uv < 2700000) { + if (priv->syscfg && priv->vdd_uv > 2700000) { + ret = regulator_enable(priv->vdd); + if (ret < 0) { + dev_err(dev, "vdd enable failed %d\n", ret); + return ret; + } + + ret = regmap_write(priv->syscfg, + STM32MP1_SYSCFG_PMCSETR, + STM32MP1_SYSCFG_ANASWVDD_MASK); + if (ret < 0) { + regulator_disable(priv->vdd); + dev_err(dev, "vdd select failed, %d\n", ret); + return ret; + } + dev_dbg(dev, "analog switches supplied by vdd\n"); + + return 0; + } + + if (priv->booster) { + /* + * This is optional, as this is a trade-off between + * analog performance and power consumption. + */ + ret = regulator_enable(priv->booster); + if (ret < 0) { + dev_err(dev, "booster enable failed %d\n", ret); + return ret; + } + dev_dbg(dev, "analog switches supplied by booster\n"); + + return 0; + } + } + + /* Fallback using vdda (default), nothing to do */ + dev_dbg(dev, "analog switches supplied by vdda (%d uV)\n", + priv->vdda_uv); + + return 0; +} + +static void stm32_adc_core_switches_supply_dis(struct stm32_adc_priv *priv) +{ + if (priv->vdda_uv < 2700000) { + if (priv->syscfg && priv->vdd_uv > 2700000) { + regmap_write(priv->syscfg, STM32MP1_SYSCFG_PMCCLRR, + STM32MP1_SYSCFG_ANASWVDD_MASK); + regulator_disable(priv->vdd); + return; + } + if (priv->booster) + regulator_disable(priv->booster); + } +} + static int stm32_adc_core_hw_start(struct device *dev) { struct stm32_adc_common *common = dev_get_drvdata(dev); @@ -402,10 +502,21 @@ static int stm32_adc_core_hw_start(struct device *dev) return ret; } + ret = regulator_get_voltage(priv->vdda); + if (ret < 0) { + dev_err(dev, "vdda get voltage failed, %d\n", ret); + goto err_vdda_disable; + } + priv->vdda_uv = ret; + + ret = stm32_adc_core_switches_supply_en(priv, dev); + if (ret < 0) + goto err_vdda_disable; + ret = regulator_enable(priv->vref); if (ret < 0) { dev_err(dev, "vref enable failed\n"); - goto err_vdda_disable; + goto err_switches_dis; } if (priv->bclk) { @@ -433,6 +544,8 @@ err_bclk_disable: clk_disable_unprepare(priv->bclk); err_regulator_disable: regulator_disable(priv->vref); +err_switches_dis: + stm32_adc_core_switches_supply_dis(priv); err_vdda_disable: regulator_disable(priv->vdda); @@ -451,9 +564,80 @@ static void stm32_adc_core_hw_stop(struct device *dev) if (priv->bclk) clk_disable_unprepare(priv->bclk); regulator_disable(priv->vref); + stm32_adc_core_switches_supply_dis(priv); regulator_disable(priv->vdda); } +static int stm32_adc_core_switches_probe(struct device *dev, + struct stm32_adc_priv *priv) +{ + struct device_node *np = dev->of_node; + int ret; + + /* Analog switches supply can be controlled by syscfg (optional) */ + priv->syscfg = syscon_regmap_lookup_by_phandle(np, "st,syscfg"); + if (IS_ERR(priv->syscfg)) { + ret = PTR_ERR(priv->syscfg); + if (ret != -ENODEV) { + if (ret != -EPROBE_DEFER) + dev_err(dev, "Can't probe syscfg: %d\n", ret); + return ret; + } + priv->syscfg = NULL; + } + + /* Booster can be used to supply analog switches (optional) */ + if (priv->cfg->has_syscfg & HAS_VBOOSTER && + of_property_read_bool(np, "booster-supply")) { + priv->booster = devm_regulator_get_optional(dev, "booster"); + if (IS_ERR(priv->booster)) { + ret = PTR_ERR(priv->booster); + if (ret != -ENODEV) { + if (ret != -EPROBE_DEFER) + dev_err(dev, "can't get booster %d\n", + ret); + return ret; + } + priv->booster = NULL; + } + } + + /* Vdd can be used to supply analog switches (optional) */ + if (priv->cfg->has_syscfg & HAS_ANASWVDD && + of_property_read_bool(np, "vdd-supply")) { + priv->vdd = devm_regulator_get_optional(dev, "vdd"); + if (IS_ERR(priv->vdd)) { + ret = PTR_ERR(priv->vdd); + if (ret != -ENODEV) { + if (ret != -EPROBE_DEFER) + dev_err(dev, "can't get vdd %d\n", ret); + return ret; + } + priv->vdd = NULL; + } + } + + if (priv->vdd) { + ret = regulator_enable(priv->vdd); + if (ret < 0) { + dev_err(dev, "vdd enable failed %d\n", ret); + return ret; + } + + ret = regulator_get_voltage(priv->vdd); + if (ret < 0) { + dev_err(dev, "vdd get voltage failed %d\n", ret); + regulator_disable(priv->vdd); + return ret; + } + priv->vdd_uv = ret; + + regulator_disable(priv->vdd); + } + + return 0; +} + static int stm32_adc_probe(struct platform_device *pdev) { struct stm32_adc_priv *priv; @@ -514,6 +698,10 @@ static int stm32_adc_probe(struct platform_device *pdev) priv->bclk = NULL; } + ret = stm32_adc_core_switches_probe(dev, priv); + if (ret) + return ret; + pm_runtime_get_noresume(dev); pm_runtime_set_active(dev); pm_runtime_set_autosuspend_delay(dev, STM32_ADC_CORE_SLEEP_DELAY_MS); @@ -611,12 +799,14 @@ static const struct stm32_adc_priv_cfg stm32h7_adc_priv_cfg = { .regs = &stm32h7_adc_common_regs, .clk_sel = stm32h7_adc_clk_sel, .max_clk_rate_hz = 36000000, + .has_syscfg = HAS_VBOOSTER, }; static const struct stm32_adc_priv_cfg stm32mp1_adc_priv_cfg = { .regs = &stm32h7_adc_common_regs, .clk_sel = stm32h7_adc_clk_sel, .max_clk_rate_hz = 40000000, + .has_syscfg = HAS_VBOOSTER | HAS_ANASWVDD, }; static const struct of_device_id stm32_adc_of_match[] = { |