1af873fceSThomas Gleixner // SPDX-License-Identifier: GPL-2.0-only 20cdbf481SFabrice Gasnier /* 30cdbf481SFabrice Gasnier * Copyright (C) STMicroelectronics 2017 40cdbf481SFabrice Gasnier * 50cdbf481SFabrice Gasnier * Author: Fabrice Gasnier <fabrice.gasnier@st.com> 60cdbf481SFabrice Gasnier */ 70cdbf481SFabrice Gasnier 80cdbf481SFabrice Gasnier #include <linux/bitfield.h> 90cdbf481SFabrice Gasnier #include <linux/clk.h> 100cdbf481SFabrice Gasnier #include <linux/io.h> 110cdbf481SFabrice Gasnier #include <linux/iopoll.h> 120cdbf481SFabrice Gasnier #include <linux/module.h> 130cdbf481SFabrice Gasnier #include <linux/of_device.h> 140cdbf481SFabrice Gasnier #include <linux/platform_device.h> 150cdbf481SFabrice Gasnier #include <linux/regulator/driver.h> 160cdbf481SFabrice Gasnier #include <linux/regulator/of_regulator.h> 17be5295f8SFabrice Gasnier #include <linux/pm_runtime.h> 180cdbf481SFabrice Gasnier 190cdbf481SFabrice Gasnier /* STM32 VREFBUF registers */ 200cdbf481SFabrice Gasnier #define STM32_VREFBUF_CSR 0x00 210cdbf481SFabrice Gasnier 220cdbf481SFabrice Gasnier /* STM32 VREFBUF CSR bitfields */ 230cdbf481SFabrice Gasnier #define STM32_VRS GENMASK(6, 4) 240cdbf481SFabrice Gasnier #define STM32_VRR BIT(3) 250cdbf481SFabrice Gasnier #define STM32_HIZ BIT(1) 260cdbf481SFabrice Gasnier #define STM32_ENVR BIT(0) 270cdbf481SFabrice Gasnier 28be5295f8SFabrice Gasnier #define STM32_VREFBUF_AUTO_SUSPEND_DELAY_MS 10 29be5295f8SFabrice Gasnier 300cdbf481SFabrice Gasnier struct stm32_vrefbuf { 310cdbf481SFabrice Gasnier void __iomem *base; 320cdbf481SFabrice Gasnier struct clk *clk; 33be5295f8SFabrice Gasnier struct device *dev; 340cdbf481SFabrice Gasnier }; 350cdbf481SFabrice Gasnier 360cdbf481SFabrice Gasnier static const unsigned int stm32_vrefbuf_voltages[] = { 370cdbf481SFabrice Gasnier /* Matches resp. VRS = 000b, 001b, 010b, 011b */ 380cdbf481SFabrice Gasnier 2500000, 2048000, 1800000, 1500000, 390cdbf481SFabrice Gasnier }; 400cdbf481SFabrice Gasnier 410cdbf481SFabrice Gasnier static int stm32_vrefbuf_enable(struct regulator_dev *rdev) 420cdbf481SFabrice Gasnier { 430cdbf481SFabrice Gasnier struct stm32_vrefbuf *priv = rdev_get_drvdata(rdev); 44be5295f8SFabrice Gasnier u32 val; 450cdbf481SFabrice Gasnier int ret; 460cdbf481SFabrice Gasnier 47be5295f8SFabrice Gasnier ret = pm_runtime_get_sync(priv->dev); 48be5295f8SFabrice Gasnier if (ret < 0) { 49be5295f8SFabrice Gasnier pm_runtime_put_noidle(priv->dev); 50be5295f8SFabrice Gasnier return ret; 51be5295f8SFabrice Gasnier } 52be5295f8SFabrice Gasnier 53be5295f8SFabrice Gasnier val = readl_relaxed(priv->base + STM32_VREFBUF_CSR); 540cdbf481SFabrice Gasnier val = (val & ~STM32_HIZ) | STM32_ENVR; 550cdbf481SFabrice Gasnier writel_relaxed(val, priv->base + STM32_VREFBUF_CSR); 560cdbf481SFabrice Gasnier 570cdbf481SFabrice Gasnier /* 580cdbf481SFabrice Gasnier * Vrefbuf startup time depends on external capacitor: wait here for 590cdbf481SFabrice Gasnier * VRR to be set. That means output has reached expected value. 600cdbf481SFabrice Gasnier * ~650us sleep should be enough for caps up to 1.5uF. Use 10ms as 610cdbf481SFabrice Gasnier * arbitrary timeout. 620cdbf481SFabrice Gasnier */ 630cdbf481SFabrice Gasnier ret = readl_poll_timeout(priv->base + STM32_VREFBUF_CSR, val, 64f63248faSFabrice Gasnier val & STM32_VRR, 650, 10000); 650cdbf481SFabrice Gasnier if (ret) { 660cdbf481SFabrice Gasnier dev_err(&rdev->dev, "stm32 vrefbuf timed out!\n"); 670cdbf481SFabrice Gasnier val = readl_relaxed(priv->base + STM32_VREFBUF_CSR); 680cdbf481SFabrice Gasnier val = (val & ~STM32_ENVR) | STM32_HIZ; 690cdbf481SFabrice Gasnier writel_relaxed(val, priv->base + STM32_VREFBUF_CSR); 700cdbf481SFabrice Gasnier } 710cdbf481SFabrice Gasnier 72be5295f8SFabrice Gasnier pm_runtime_mark_last_busy(priv->dev); 73be5295f8SFabrice Gasnier pm_runtime_put_autosuspend(priv->dev); 74be5295f8SFabrice Gasnier 750cdbf481SFabrice Gasnier return ret; 760cdbf481SFabrice Gasnier } 770cdbf481SFabrice Gasnier 780cdbf481SFabrice Gasnier static int stm32_vrefbuf_disable(struct regulator_dev *rdev) 790cdbf481SFabrice Gasnier { 800cdbf481SFabrice Gasnier struct stm32_vrefbuf *priv = rdev_get_drvdata(rdev); 81be5295f8SFabrice Gasnier u32 val; 82be5295f8SFabrice Gasnier int ret; 830cdbf481SFabrice Gasnier 84be5295f8SFabrice Gasnier ret = pm_runtime_get_sync(priv->dev); 85be5295f8SFabrice Gasnier if (ret < 0) { 86be5295f8SFabrice Gasnier pm_runtime_put_noidle(priv->dev); 87be5295f8SFabrice Gasnier return ret; 88be5295f8SFabrice Gasnier } 89be5295f8SFabrice Gasnier 90be5295f8SFabrice Gasnier val = readl_relaxed(priv->base + STM32_VREFBUF_CSR); 9102fbabd5SFabrice Gasnier val &= ~STM32_ENVR; 920cdbf481SFabrice Gasnier writel_relaxed(val, priv->base + STM32_VREFBUF_CSR); 930cdbf481SFabrice Gasnier 94be5295f8SFabrice Gasnier pm_runtime_mark_last_busy(priv->dev); 95be5295f8SFabrice Gasnier pm_runtime_put_autosuspend(priv->dev); 96be5295f8SFabrice Gasnier 970cdbf481SFabrice Gasnier return 0; 980cdbf481SFabrice Gasnier } 990cdbf481SFabrice Gasnier 1000cdbf481SFabrice Gasnier static int stm32_vrefbuf_is_enabled(struct regulator_dev *rdev) 1010cdbf481SFabrice Gasnier { 1020cdbf481SFabrice Gasnier struct stm32_vrefbuf *priv = rdev_get_drvdata(rdev); 103be5295f8SFabrice Gasnier int ret; 1040cdbf481SFabrice Gasnier 105be5295f8SFabrice Gasnier ret = pm_runtime_get_sync(priv->dev); 106be5295f8SFabrice Gasnier if (ret < 0) { 107be5295f8SFabrice Gasnier pm_runtime_put_noidle(priv->dev); 108be5295f8SFabrice Gasnier return ret; 109be5295f8SFabrice Gasnier } 110be5295f8SFabrice Gasnier 111be5295f8SFabrice Gasnier ret = readl_relaxed(priv->base + STM32_VREFBUF_CSR) & STM32_ENVR; 112be5295f8SFabrice Gasnier 113be5295f8SFabrice Gasnier pm_runtime_mark_last_busy(priv->dev); 114be5295f8SFabrice Gasnier pm_runtime_put_autosuspend(priv->dev); 115be5295f8SFabrice Gasnier 116be5295f8SFabrice Gasnier return ret; 1170cdbf481SFabrice Gasnier } 1180cdbf481SFabrice Gasnier 1190cdbf481SFabrice Gasnier static int stm32_vrefbuf_set_voltage_sel(struct regulator_dev *rdev, 1200cdbf481SFabrice Gasnier unsigned sel) 1210cdbf481SFabrice Gasnier { 1220cdbf481SFabrice Gasnier struct stm32_vrefbuf *priv = rdev_get_drvdata(rdev); 123be5295f8SFabrice Gasnier u32 val; 124be5295f8SFabrice Gasnier int ret; 1250cdbf481SFabrice Gasnier 126be5295f8SFabrice Gasnier ret = pm_runtime_get_sync(priv->dev); 127be5295f8SFabrice Gasnier if (ret < 0) { 128be5295f8SFabrice Gasnier pm_runtime_put_noidle(priv->dev); 129be5295f8SFabrice Gasnier return ret; 130be5295f8SFabrice Gasnier } 131be5295f8SFabrice Gasnier 132be5295f8SFabrice Gasnier val = readl_relaxed(priv->base + STM32_VREFBUF_CSR); 1330cdbf481SFabrice Gasnier val = (val & ~STM32_VRS) | FIELD_PREP(STM32_VRS, sel); 1340cdbf481SFabrice Gasnier writel_relaxed(val, priv->base + STM32_VREFBUF_CSR); 1350cdbf481SFabrice Gasnier 136be5295f8SFabrice Gasnier pm_runtime_mark_last_busy(priv->dev); 137be5295f8SFabrice Gasnier pm_runtime_put_autosuspend(priv->dev); 138be5295f8SFabrice Gasnier 1390cdbf481SFabrice Gasnier return 0; 1400cdbf481SFabrice Gasnier } 1410cdbf481SFabrice Gasnier 1420cdbf481SFabrice Gasnier static int stm32_vrefbuf_get_voltage_sel(struct regulator_dev *rdev) 1430cdbf481SFabrice Gasnier { 1440cdbf481SFabrice Gasnier struct stm32_vrefbuf *priv = rdev_get_drvdata(rdev); 145be5295f8SFabrice Gasnier u32 val; 146be5295f8SFabrice Gasnier int ret; 1470cdbf481SFabrice Gasnier 148be5295f8SFabrice Gasnier ret = pm_runtime_get_sync(priv->dev); 149be5295f8SFabrice Gasnier if (ret < 0) { 150be5295f8SFabrice Gasnier pm_runtime_put_noidle(priv->dev); 151be5295f8SFabrice Gasnier return ret; 152be5295f8SFabrice Gasnier } 153be5295f8SFabrice Gasnier 154be5295f8SFabrice Gasnier val = readl_relaxed(priv->base + STM32_VREFBUF_CSR); 155be5295f8SFabrice Gasnier ret = FIELD_GET(STM32_VRS, val); 156be5295f8SFabrice Gasnier 157be5295f8SFabrice Gasnier pm_runtime_mark_last_busy(priv->dev); 158be5295f8SFabrice Gasnier pm_runtime_put_autosuspend(priv->dev); 159be5295f8SFabrice Gasnier 160be5295f8SFabrice Gasnier return ret; 1610cdbf481SFabrice Gasnier } 1620cdbf481SFabrice Gasnier 1630cdbf481SFabrice Gasnier static const struct regulator_ops stm32_vrefbuf_volt_ops = { 1640cdbf481SFabrice Gasnier .enable = stm32_vrefbuf_enable, 1650cdbf481SFabrice Gasnier .disable = stm32_vrefbuf_disable, 1660cdbf481SFabrice Gasnier .is_enabled = stm32_vrefbuf_is_enabled, 1670cdbf481SFabrice Gasnier .get_voltage_sel = stm32_vrefbuf_get_voltage_sel, 1680cdbf481SFabrice Gasnier .set_voltage_sel = stm32_vrefbuf_set_voltage_sel, 1690cdbf481SFabrice Gasnier .list_voltage = regulator_list_voltage_table, 1700cdbf481SFabrice Gasnier }; 1710cdbf481SFabrice Gasnier 1720cdbf481SFabrice Gasnier static const struct regulator_desc stm32_vrefbuf_regu = { 1730cdbf481SFabrice Gasnier .name = "vref", 1740cdbf481SFabrice Gasnier .supply_name = "vdda", 1750cdbf481SFabrice Gasnier .volt_table = stm32_vrefbuf_voltages, 1760cdbf481SFabrice Gasnier .n_voltages = ARRAY_SIZE(stm32_vrefbuf_voltages), 1770cdbf481SFabrice Gasnier .ops = &stm32_vrefbuf_volt_ops, 17802fbabd5SFabrice Gasnier .off_on_delay = 1000, 1790cdbf481SFabrice Gasnier .type = REGULATOR_VOLTAGE, 1800cdbf481SFabrice Gasnier .owner = THIS_MODULE, 1810cdbf481SFabrice Gasnier }; 1820cdbf481SFabrice Gasnier 1830cdbf481SFabrice Gasnier static int stm32_vrefbuf_probe(struct platform_device *pdev) 1840cdbf481SFabrice Gasnier { 1850cdbf481SFabrice Gasnier struct stm32_vrefbuf *priv; 1860cdbf481SFabrice Gasnier struct regulator_config config = { }; 1870cdbf481SFabrice Gasnier struct regulator_dev *rdev; 1880cdbf481SFabrice Gasnier int ret; 1890cdbf481SFabrice Gasnier 1900cdbf481SFabrice Gasnier priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL); 1910cdbf481SFabrice Gasnier if (!priv) 1920cdbf481SFabrice Gasnier return -ENOMEM; 193be5295f8SFabrice Gasnier priv->dev = &pdev->dev; 1940cdbf481SFabrice Gasnier 19573511a90SYueHaibing priv->base = devm_platform_ioremap_resource(pdev, 0); 1960cdbf481SFabrice Gasnier if (IS_ERR(priv->base)) 1970cdbf481SFabrice Gasnier return PTR_ERR(priv->base); 1980cdbf481SFabrice Gasnier 1990cdbf481SFabrice Gasnier priv->clk = devm_clk_get(&pdev->dev, NULL); 2000cdbf481SFabrice Gasnier if (IS_ERR(priv->clk)) 2010cdbf481SFabrice Gasnier return PTR_ERR(priv->clk); 2020cdbf481SFabrice Gasnier 203be5295f8SFabrice Gasnier pm_runtime_get_noresume(&pdev->dev); 204be5295f8SFabrice Gasnier pm_runtime_set_active(&pdev->dev); 205be5295f8SFabrice Gasnier pm_runtime_set_autosuspend_delay(&pdev->dev, 206be5295f8SFabrice Gasnier STM32_VREFBUF_AUTO_SUSPEND_DELAY_MS); 207be5295f8SFabrice Gasnier pm_runtime_use_autosuspend(&pdev->dev); 208be5295f8SFabrice Gasnier pm_runtime_enable(&pdev->dev); 209be5295f8SFabrice Gasnier 2100cdbf481SFabrice Gasnier ret = clk_prepare_enable(priv->clk); 2110cdbf481SFabrice Gasnier if (ret) { 2120cdbf481SFabrice Gasnier dev_err(&pdev->dev, "clk prepare failed with error %d\n", ret); 213be5295f8SFabrice Gasnier goto err_pm_stop; 2140cdbf481SFabrice Gasnier } 2150cdbf481SFabrice Gasnier 2160cdbf481SFabrice Gasnier config.dev = &pdev->dev; 2170cdbf481SFabrice Gasnier config.driver_data = priv; 2180cdbf481SFabrice Gasnier config.of_node = pdev->dev.of_node; 2190cdbf481SFabrice Gasnier config.init_data = of_get_regulator_init_data(&pdev->dev, 2200cdbf481SFabrice Gasnier pdev->dev.of_node, 2210cdbf481SFabrice Gasnier &stm32_vrefbuf_regu); 2220cdbf481SFabrice Gasnier 2230cdbf481SFabrice Gasnier rdev = regulator_register(&stm32_vrefbuf_regu, &config); 2240cdbf481SFabrice Gasnier if (IS_ERR(rdev)) { 2250cdbf481SFabrice Gasnier ret = PTR_ERR(rdev); 2260cdbf481SFabrice Gasnier dev_err(&pdev->dev, "register failed with error %d\n", ret); 2270cdbf481SFabrice Gasnier goto err_clk_dis; 2280cdbf481SFabrice Gasnier } 2290cdbf481SFabrice Gasnier platform_set_drvdata(pdev, rdev); 2300cdbf481SFabrice Gasnier 231be5295f8SFabrice Gasnier pm_runtime_mark_last_busy(&pdev->dev); 232be5295f8SFabrice Gasnier pm_runtime_put_autosuspend(&pdev->dev); 233be5295f8SFabrice Gasnier 2340cdbf481SFabrice Gasnier return 0; 2350cdbf481SFabrice Gasnier 2360cdbf481SFabrice Gasnier err_clk_dis: 2370cdbf481SFabrice Gasnier clk_disable_unprepare(priv->clk); 238be5295f8SFabrice Gasnier err_pm_stop: 239be5295f8SFabrice Gasnier pm_runtime_disable(&pdev->dev); 240be5295f8SFabrice Gasnier pm_runtime_set_suspended(&pdev->dev); 241be5295f8SFabrice Gasnier pm_runtime_put_noidle(&pdev->dev); 2420cdbf481SFabrice Gasnier 2430cdbf481SFabrice Gasnier return ret; 2440cdbf481SFabrice Gasnier } 2450cdbf481SFabrice Gasnier 2460cdbf481SFabrice Gasnier static int stm32_vrefbuf_remove(struct platform_device *pdev) 2470cdbf481SFabrice Gasnier { 2480cdbf481SFabrice Gasnier struct regulator_dev *rdev = platform_get_drvdata(pdev); 2490cdbf481SFabrice Gasnier struct stm32_vrefbuf *priv = rdev_get_drvdata(rdev); 2500cdbf481SFabrice Gasnier 251be5295f8SFabrice Gasnier pm_runtime_get_sync(&pdev->dev); 2520cdbf481SFabrice Gasnier regulator_unregister(rdev); 2530cdbf481SFabrice Gasnier clk_disable_unprepare(priv->clk); 254be5295f8SFabrice Gasnier pm_runtime_disable(&pdev->dev); 255be5295f8SFabrice Gasnier pm_runtime_set_suspended(&pdev->dev); 256be5295f8SFabrice Gasnier pm_runtime_put_noidle(&pdev->dev); 257be5295f8SFabrice Gasnier 258be5295f8SFabrice Gasnier return 0; 259be5295f8SFabrice Gasnier }; 260be5295f8SFabrice Gasnier 261be5295f8SFabrice Gasnier static int __maybe_unused stm32_vrefbuf_runtime_suspend(struct device *dev) 262be5295f8SFabrice Gasnier { 263be5295f8SFabrice Gasnier struct regulator_dev *rdev = dev_get_drvdata(dev); 264be5295f8SFabrice Gasnier struct stm32_vrefbuf *priv = rdev_get_drvdata(rdev); 265be5295f8SFabrice Gasnier 266be5295f8SFabrice Gasnier clk_disable_unprepare(priv->clk); 2670cdbf481SFabrice Gasnier 2680cdbf481SFabrice Gasnier return 0; 269be5295f8SFabrice Gasnier } 270be5295f8SFabrice Gasnier 271be5295f8SFabrice Gasnier static int __maybe_unused stm32_vrefbuf_runtime_resume(struct device *dev) 272be5295f8SFabrice Gasnier { 273be5295f8SFabrice Gasnier struct regulator_dev *rdev = dev_get_drvdata(dev); 274be5295f8SFabrice Gasnier struct stm32_vrefbuf *priv = rdev_get_drvdata(rdev); 275be5295f8SFabrice Gasnier 276be5295f8SFabrice Gasnier return clk_prepare_enable(priv->clk); 277be5295f8SFabrice Gasnier } 278be5295f8SFabrice Gasnier 279be5295f8SFabrice Gasnier static const struct dev_pm_ops stm32_vrefbuf_pm_ops = { 280be5295f8SFabrice Gasnier SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend, 281be5295f8SFabrice Gasnier pm_runtime_force_resume) 282be5295f8SFabrice Gasnier SET_RUNTIME_PM_OPS(stm32_vrefbuf_runtime_suspend, 283be5295f8SFabrice Gasnier stm32_vrefbuf_runtime_resume, 284be5295f8SFabrice Gasnier NULL) 2850cdbf481SFabrice Gasnier }; 2860cdbf481SFabrice Gasnier 287*d5579e7aSJisheng Zhang static const struct of_device_id __maybe_unused stm32_vrefbuf_of_match[] = { 2880cdbf481SFabrice Gasnier { .compatible = "st,stm32-vrefbuf", }, 2890cdbf481SFabrice Gasnier {}, 2900cdbf481SFabrice Gasnier }; 2910cdbf481SFabrice Gasnier MODULE_DEVICE_TABLE(of, stm32_vrefbuf_of_match); 2920cdbf481SFabrice Gasnier 2930cdbf481SFabrice Gasnier static struct platform_driver stm32_vrefbuf_driver = { 2940cdbf481SFabrice Gasnier .probe = stm32_vrefbuf_probe, 2950cdbf481SFabrice Gasnier .remove = stm32_vrefbuf_remove, 2960cdbf481SFabrice Gasnier .driver = { 2970cdbf481SFabrice Gasnier .name = "stm32-vrefbuf", 2980cdbf481SFabrice Gasnier .of_match_table = of_match_ptr(stm32_vrefbuf_of_match), 299be5295f8SFabrice Gasnier .pm = &stm32_vrefbuf_pm_ops, 3000cdbf481SFabrice Gasnier }, 3010cdbf481SFabrice Gasnier }; 3020cdbf481SFabrice Gasnier module_platform_driver(stm32_vrefbuf_driver); 3030cdbf481SFabrice Gasnier 3040cdbf481SFabrice Gasnier MODULE_LICENSE("GPL v2"); 3050cdbf481SFabrice Gasnier MODULE_AUTHOR("Fabrice Gasnier <fabrice.gasnier@st.com>"); 3060cdbf481SFabrice Gasnier MODULE_DESCRIPTION("STMicroelectronics STM32 VREFBUF driver"); 3070cdbf481SFabrice Gasnier MODULE_ALIAS("platform:stm32-vrefbuf"); 308