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 47bfb5711eSMinghao Chi ret = pm_runtime_resume_and_get(priv->dev); 48bfb5711eSMinghao Chi if (ret < 0) 49be5295f8SFabrice Gasnier return ret; 50be5295f8SFabrice Gasnier 51be5295f8SFabrice Gasnier val = readl_relaxed(priv->base + STM32_VREFBUF_CSR); 520cdbf481SFabrice Gasnier val = (val & ~STM32_HIZ) | STM32_ENVR; 530cdbf481SFabrice Gasnier writel_relaxed(val, priv->base + STM32_VREFBUF_CSR); 540cdbf481SFabrice Gasnier 550cdbf481SFabrice Gasnier /* 560cdbf481SFabrice Gasnier * Vrefbuf startup time depends on external capacitor: wait here for 570cdbf481SFabrice Gasnier * VRR to be set. That means output has reached expected value. 580cdbf481SFabrice Gasnier * ~650us sleep should be enough for caps up to 1.5uF. Use 10ms as 590cdbf481SFabrice Gasnier * arbitrary timeout. 600cdbf481SFabrice Gasnier */ 610cdbf481SFabrice Gasnier ret = readl_poll_timeout(priv->base + STM32_VREFBUF_CSR, val, 62f63248faSFabrice Gasnier val & STM32_VRR, 650, 10000); 630cdbf481SFabrice Gasnier if (ret) { 640cdbf481SFabrice Gasnier dev_err(&rdev->dev, "stm32 vrefbuf timed out!\n"); 650cdbf481SFabrice Gasnier val = readl_relaxed(priv->base + STM32_VREFBUF_CSR); 660cdbf481SFabrice Gasnier val = (val & ~STM32_ENVR) | STM32_HIZ; 670cdbf481SFabrice Gasnier writel_relaxed(val, priv->base + STM32_VREFBUF_CSR); 680cdbf481SFabrice Gasnier } 690cdbf481SFabrice Gasnier 70be5295f8SFabrice Gasnier pm_runtime_mark_last_busy(priv->dev); 71be5295f8SFabrice Gasnier pm_runtime_put_autosuspend(priv->dev); 72be5295f8SFabrice Gasnier 730cdbf481SFabrice Gasnier return ret; 740cdbf481SFabrice Gasnier } 750cdbf481SFabrice Gasnier 760cdbf481SFabrice Gasnier static int stm32_vrefbuf_disable(struct regulator_dev *rdev) 770cdbf481SFabrice Gasnier { 780cdbf481SFabrice Gasnier struct stm32_vrefbuf *priv = rdev_get_drvdata(rdev); 79be5295f8SFabrice Gasnier u32 val; 80be5295f8SFabrice Gasnier int ret; 810cdbf481SFabrice Gasnier 82bfb5711eSMinghao Chi ret = pm_runtime_resume_and_get(priv->dev); 83bfb5711eSMinghao Chi if (ret < 0) 84be5295f8SFabrice Gasnier return ret; 85be5295f8SFabrice Gasnier 86be5295f8SFabrice Gasnier val = readl_relaxed(priv->base + STM32_VREFBUF_CSR); 8702fbabd5SFabrice Gasnier val &= ~STM32_ENVR; 880cdbf481SFabrice Gasnier writel_relaxed(val, priv->base + STM32_VREFBUF_CSR); 890cdbf481SFabrice Gasnier 90be5295f8SFabrice Gasnier pm_runtime_mark_last_busy(priv->dev); 91be5295f8SFabrice Gasnier pm_runtime_put_autosuspend(priv->dev); 92be5295f8SFabrice Gasnier 930cdbf481SFabrice Gasnier return 0; 940cdbf481SFabrice Gasnier } 950cdbf481SFabrice Gasnier 960cdbf481SFabrice Gasnier static int stm32_vrefbuf_is_enabled(struct regulator_dev *rdev) 970cdbf481SFabrice Gasnier { 980cdbf481SFabrice Gasnier struct stm32_vrefbuf *priv = rdev_get_drvdata(rdev); 99be5295f8SFabrice Gasnier int ret; 1000cdbf481SFabrice Gasnier 101bfb5711eSMinghao Chi ret = pm_runtime_resume_and_get(priv->dev); 102bfb5711eSMinghao Chi if (ret < 0) 103be5295f8SFabrice Gasnier return ret; 104be5295f8SFabrice Gasnier 105be5295f8SFabrice Gasnier ret = readl_relaxed(priv->base + STM32_VREFBUF_CSR) & STM32_ENVR; 106be5295f8SFabrice Gasnier 107be5295f8SFabrice Gasnier pm_runtime_mark_last_busy(priv->dev); 108be5295f8SFabrice Gasnier pm_runtime_put_autosuspend(priv->dev); 109be5295f8SFabrice Gasnier 110be5295f8SFabrice Gasnier return ret; 1110cdbf481SFabrice Gasnier } 1120cdbf481SFabrice Gasnier 1130cdbf481SFabrice Gasnier static int stm32_vrefbuf_set_voltage_sel(struct regulator_dev *rdev, 1140cdbf481SFabrice Gasnier unsigned sel) 1150cdbf481SFabrice Gasnier { 1160cdbf481SFabrice Gasnier struct stm32_vrefbuf *priv = rdev_get_drvdata(rdev); 117be5295f8SFabrice Gasnier u32 val; 118be5295f8SFabrice Gasnier int ret; 1190cdbf481SFabrice Gasnier 120bfb5711eSMinghao Chi ret = pm_runtime_resume_and_get(priv->dev); 121bfb5711eSMinghao Chi if (ret < 0) 122be5295f8SFabrice Gasnier return ret; 123be5295f8SFabrice Gasnier 124be5295f8SFabrice Gasnier val = readl_relaxed(priv->base + STM32_VREFBUF_CSR); 1250cdbf481SFabrice Gasnier val = (val & ~STM32_VRS) | FIELD_PREP(STM32_VRS, sel); 1260cdbf481SFabrice Gasnier writel_relaxed(val, priv->base + STM32_VREFBUF_CSR); 1270cdbf481SFabrice Gasnier 128be5295f8SFabrice Gasnier pm_runtime_mark_last_busy(priv->dev); 129be5295f8SFabrice Gasnier pm_runtime_put_autosuspend(priv->dev); 130be5295f8SFabrice Gasnier 1310cdbf481SFabrice Gasnier return 0; 1320cdbf481SFabrice Gasnier } 1330cdbf481SFabrice Gasnier 1340cdbf481SFabrice Gasnier static int stm32_vrefbuf_get_voltage_sel(struct regulator_dev *rdev) 1350cdbf481SFabrice Gasnier { 1360cdbf481SFabrice Gasnier struct stm32_vrefbuf *priv = rdev_get_drvdata(rdev); 137be5295f8SFabrice Gasnier u32 val; 138be5295f8SFabrice Gasnier int ret; 1390cdbf481SFabrice Gasnier 140bfb5711eSMinghao Chi ret = pm_runtime_resume_and_get(priv->dev); 141bfb5711eSMinghao Chi if (ret < 0) 142be5295f8SFabrice Gasnier return ret; 143be5295f8SFabrice Gasnier 144be5295f8SFabrice Gasnier val = readl_relaxed(priv->base + STM32_VREFBUF_CSR); 145be5295f8SFabrice Gasnier ret = FIELD_GET(STM32_VRS, val); 146be5295f8SFabrice Gasnier 147be5295f8SFabrice Gasnier pm_runtime_mark_last_busy(priv->dev); 148be5295f8SFabrice Gasnier pm_runtime_put_autosuspend(priv->dev); 149be5295f8SFabrice Gasnier 150be5295f8SFabrice Gasnier return ret; 1510cdbf481SFabrice Gasnier } 1520cdbf481SFabrice Gasnier 1530cdbf481SFabrice Gasnier static const struct regulator_ops stm32_vrefbuf_volt_ops = { 1540cdbf481SFabrice Gasnier .enable = stm32_vrefbuf_enable, 1550cdbf481SFabrice Gasnier .disable = stm32_vrefbuf_disable, 1560cdbf481SFabrice Gasnier .is_enabled = stm32_vrefbuf_is_enabled, 1570cdbf481SFabrice Gasnier .get_voltage_sel = stm32_vrefbuf_get_voltage_sel, 1580cdbf481SFabrice Gasnier .set_voltage_sel = stm32_vrefbuf_set_voltage_sel, 1590cdbf481SFabrice Gasnier .list_voltage = regulator_list_voltage_table, 1600cdbf481SFabrice Gasnier }; 1610cdbf481SFabrice Gasnier 1620cdbf481SFabrice Gasnier static const struct regulator_desc stm32_vrefbuf_regu = { 1630cdbf481SFabrice Gasnier .name = "vref", 1640cdbf481SFabrice Gasnier .supply_name = "vdda", 1650cdbf481SFabrice Gasnier .volt_table = stm32_vrefbuf_voltages, 1660cdbf481SFabrice Gasnier .n_voltages = ARRAY_SIZE(stm32_vrefbuf_voltages), 1670cdbf481SFabrice Gasnier .ops = &stm32_vrefbuf_volt_ops, 16802fbabd5SFabrice Gasnier .off_on_delay = 1000, 1690cdbf481SFabrice Gasnier .type = REGULATOR_VOLTAGE, 1700cdbf481SFabrice Gasnier .owner = THIS_MODULE, 1710cdbf481SFabrice Gasnier }; 1720cdbf481SFabrice Gasnier 1730cdbf481SFabrice Gasnier static int stm32_vrefbuf_probe(struct platform_device *pdev) 1740cdbf481SFabrice Gasnier { 1750cdbf481SFabrice Gasnier struct stm32_vrefbuf *priv; 1760cdbf481SFabrice Gasnier struct regulator_config config = { }; 1770cdbf481SFabrice Gasnier struct regulator_dev *rdev; 1780cdbf481SFabrice Gasnier int ret; 1790cdbf481SFabrice Gasnier 1800cdbf481SFabrice Gasnier priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL); 1810cdbf481SFabrice Gasnier if (!priv) 1820cdbf481SFabrice Gasnier return -ENOMEM; 183be5295f8SFabrice Gasnier priv->dev = &pdev->dev; 1840cdbf481SFabrice Gasnier 18573511a90SYueHaibing priv->base = devm_platform_ioremap_resource(pdev, 0); 1860cdbf481SFabrice Gasnier if (IS_ERR(priv->base)) 1870cdbf481SFabrice Gasnier return PTR_ERR(priv->base); 1880cdbf481SFabrice Gasnier 1890cdbf481SFabrice Gasnier priv->clk = devm_clk_get(&pdev->dev, NULL); 1900cdbf481SFabrice Gasnier if (IS_ERR(priv->clk)) 1910cdbf481SFabrice Gasnier return PTR_ERR(priv->clk); 1920cdbf481SFabrice Gasnier 193be5295f8SFabrice Gasnier pm_runtime_get_noresume(&pdev->dev); 194be5295f8SFabrice Gasnier pm_runtime_set_active(&pdev->dev); 195be5295f8SFabrice Gasnier pm_runtime_set_autosuspend_delay(&pdev->dev, 196be5295f8SFabrice Gasnier STM32_VREFBUF_AUTO_SUSPEND_DELAY_MS); 197be5295f8SFabrice Gasnier pm_runtime_use_autosuspend(&pdev->dev); 198be5295f8SFabrice Gasnier pm_runtime_enable(&pdev->dev); 199be5295f8SFabrice Gasnier 2000cdbf481SFabrice Gasnier ret = clk_prepare_enable(priv->clk); 2010cdbf481SFabrice Gasnier if (ret) { 2020cdbf481SFabrice Gasnier dev_err(&pdev->dev, "clk prepare failed with error %d\n", ret); 203be5295f8SFabrice Gasnier goto err_pm_stop; 2040cdbf481SFabrice Gasnier } 2050cdbf481SFabrice Gasnier 2060cdbf481SFabrice Gasnier config.dev = &pdev->dev; 2070cdbf481SFabrice Gasnier config.driver_data = priv; 2080cdbf481SFabrice Gasnier config.of_node = pdev->dev.of_node; 2090cdbf481SFabrice Gasnier config.init_data = of_get_regulator_init_data(&pdev->dev, 2100cdbf481SFabrice Gasnier pdev->dev.of_node, 2110cdbf481SFabrice Gasnier &stm32_vrefbuf_regu); 2120cdbf481SFabrice Gasnier 213*8f3cbcd6SChiYuan Huang rdev = regulator_register(&pdev->dev, &stm32_vrefbuf_regu, &config); 2140cdbf481SFabrice Gasnier if (IS_ERR(rdev)) { 2150cdbf481SFabrice Gasnier ret = PTR_ERR(rdev); 2160cdbf481SFabrice Gasnier dev_err(&pdev->dev, "register failed with error %d\n", ret); 2170cdbf481SFabrice Gasnier goto err_clk_dis; 2180cdbf481SFabrice Gasnier } 2190cdbf481SFabrice Gasnier platform_set_drvdata(pdev, rdev); 2200cdbf481SFabrice Gasnier 221be5295f8SFabrice Gasnier pm_runtime_mark_last_busy(&pdev->dev); 222be5295f8SFabrice Gasnier pm_runtime_put_autosuspend(&pdev->dev); 223be5295f8SFabrice Gasnier 2240cdbf481SFabrice Gasnier return 0; 2250cdbf481SFabrice Gasnier 2260cdbf481SFabrice Gasnier err_clk_dis: 2270cdbf481SFabrice Gasnier clk_disable_unprepare(priv->clk); 228be5295f8SFabrice Gasnier err_pm_stop: 229be5295f8SFabrice Gasnier pm_runtime_disable(&pdev->dev); 230be5295f8SFabrice Gasnier pm_runtime_set_suspended(&pdev->dev); 231be5295f8SFabrice Gasnier pm_runtime_put_noidle(&pdev->dev); 2320cdbf481SFabrice Gasnier 2330cdbf481SFabrice Gasnier return ret; 2340cdbf481SFabrice Gasnier } 2350cdbf481SFabrice Gasnier 2360cdbf481SFabrice Gasnier static int stm32_vrefbuf_remove(struct platform_device *pdev) 2370cdbf481SFabrice Gasnier { 2380cdbf481SFabrice Gasnier struct regulator_dev *rdev = platform_get_drvdata(pdev); 2390cdbf481SFabrice Gasnier struct stm32_vrefbuf *priv = rdev_get_drvdata(rdev); 2400cdbf481SFabrice Gasnier 241be5295f8SFabrice Gasnier pm_runtime_get_sync(&pdev->dev); 2420cdbf481SFabrice Gasnier regulator_unregister(rdev); 2430cdbf481SFabrice Gasnier clk_disable_unprepare(priv->clk); 244be5295f8SFabrice Gasnier pm_runtime_disable(&pdev->dev); 245be5295f8SFabrice Gasnier pm_runtime_set_suspended(&pdev->dev); 246be5295f8SFabrice Gasnier pm_runtime_put_noidle(&pdev->dev); 247be5295f8SFabrice Gasnier 248be5295f8SFabrice Gasnier return 0; 249be5295f8SFabrice Gasnier }; 250be5295f8SFabrice Gasnier 251be5295f8SFabrice Gasnier static int __maybe_unused stm32_vrefbuf_runtime_suspend(struct device *dev) 252be5295f8SFabrice Gasnier { 253be5295f8SFabrice Gasnier struct regulator_dev *rdev = dev_get_drvdata(dev); 254be5295f8SFabrice Gasnier struct stm32_vrefbuf *priv = rdev_get_drvdata(rdev); 255be5295f8SFabrice Gasnier 256be5295f8SFabrice Gasnier clk_disable_unprepare(priv->clk); 2570cdbf481SFabrice Gasnier 2580cdbf481SFabrice Gasnier return 0; 259be5295f8SFabrice Gasnier } 260be5295f8SFabrice Gasnier 261be5295f8SFabrice Gasnier static int __maybe_unused stm32_vrefbuf_runtime_resume(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 return clk_prepare_enable(priv->clk); 267be5295f8SFabrice Gasnier } 268be5295f8SFabrice Gasnier 269be5295f8SFabrice Gasnier static const struct dev_pm_ops stm32_vrefbuf_pm_ops = { 270be5295f8SFabrice Gasnier SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend, 271be5295f8SFabrice Gasnier pm_runtime_force_resume) 272be5295f8SFabrice Gasnier SET_RUNTIME_PM_OPS(stm32_vrefbuf_runtime_suspend, 273be5295f8SFabrice Gasnier stm32_vrefbuf_runtime_resume, 274be5295f8SFabrice Gasnier NULL) 2750cdbf481SFabrice Gasnier }; 2760cdbf481SFabrice Gasnier 277d5579e7aSJisheng Zhang static const struct of_device_id __maybe_unused stm32_vrefbuf_of_match[] = { 2780cdbf481SFabrice Gasnier { .compatible = "st,stm32-vrefbuf", }, 2790cdbf481SFabrice Gasnier {}, 2800cdbf481SFabrice Gasnier }; 2810cdbf481SFabrice Gasnier MODULE_DEVICE_TABLE(of, stm32_vrefbuf_of_match); 2820cdbf481SFabrice Gasnier 2830cdbf481SFabrice Gasnier static struct platform_driver stm32_vrefbuf_driver = { 2840cdbf481SFabrice Gasnier .probe = stm32_vrefbuf_probe, 2850cdbf481SFabrice Gasnier .remove = stm32_vrefbuf_remove, 2860cdbf481SFabrice Gasnier .driver = { 2870cdbf481SFabrice Gasnier .name = "stm32-vrefbuf", 2880cdbf481SFabrice Gasnier .of_match_table = of_match_ptr(stm32_vrefbuf_of_match), 289be5295f8SFabrice Gasnier .pm = &stm32_vrefbuf_pm_ops, 2900cdbf481SFabrice Gasnier }, 2910cdbf481SFabrice Gasnier }; 2920cdbf481SFabrice Gasnier module_platform_driver(stm32_vrefbuf_driver); 2930cdbf481SFabrice Gasnier 2940cdbf481SFabrice Gasnier MODULE_LICENSE("GPL v2"); 2950cdbf481SFabrice Gasnier MODULE_AUTHOR("Fabrice Gasnier <fabrice.gasnier@st.com>"); 2960cdbf481SFabrice Gasnier MODULE_DESCRIPTION("STMicroelectronics STM32 VREFBUF driver"); 2970cdbf481SFabrice Gasnier MODULE_ALIAS("platform:stm32-vrefbuf"); 298