Thomas Gleixner | af873fc | 2019-05-28 09:57:21 -0700 | [diff] [blame] | 1 | // SPDX-License-Identifier: GPL-2.0-only |
Fabrice Gasnier | 0cdbf48 | 2017-08-30 17:55:28 +0200 | [diff] [blame] | 2 | /* |
| 3 | * Copyright (C) STMicroelectronics 2017 |
| 4 | * |
| 5 | * Author: Fabrice Gasnier <fabrice.gasnier@st.com> |
Fabrice Gasnier | 0cdbf48 | 2017-08-30 17:55:28 +0200 | [diff] [blame] | 6 | */ |
| 7 | |
| 8 | #include <linux/bitfield.h> |
| 9 | #include <linux/clk.h> |
| 10 | #include <linux/io.h> |
| 11 | #include <linux/iopoll.h> |
| 12 | #include <linux/module.h> |
| 13 | #include <linux/of_device.h> |
| 14 | #include <linux/platform_device.h> |
| 15 | #include <linux/regulator/driver.h> |
| 16 | #include <linux/regulator/of_regulator.h> |
Fabrice Gasnier | be5295f | 2019-02-28 11:45:18 +0100 | [diff] [blame] | 17 | #include <linux/pm_runtime.h> |
Fabrice Gasnier | 0cdbf48 | 2017-08-30 17:55:28 +0200 | [diff] [blame] | 18 | |
| 19 | /* STM32 VREFBUF registers */ |
| 20 | #define STM32_VREFBUF_CSR 0x00 |
| 21 | |
| 22 | /* STM32 VREFBUF CSR bitfields */ |
| 23 | #define STM32_VRS GENMASK(6, 4) |
| 24 | #define STM32_VRR BIT(3) |
| 25 | #define STM32_HIZ BIT(1) |
| 26 | #define STM32_ENVR BIT(0) |
| 27 | |
Fabrice Gasnier | be5295f | 2019-02-28 11:45:18 +0100 | [diff] [blame] | 28 | #define STM32_VREFBUF_AUTO_SUSPEND_DELAY_MS 10 |
| 29 | |
Fabrice Gasnier | 0cdbf48 | 2017-08-30 17:55:28 +0200 | [diff] [blame] | 30 | struct stm32_vrefbuf { |
| 31 | void __iomem *base; |
| 32 | struct clk *clk; |
Fabrice Gasnier | be5295f | 2019-02-28 11:45:18 +0100 | [diff] [blame] | 33 | struct device *dev; |
Fabrice Gasnier | 0cdbf48 | 2017-08-30 17:55:28 +0200 | [diff] [blame] | 34 | }; |
| 35 | |
| 36 | static const unsigned int stm32_vrefbuf_voltages[] = { |
| 37 | /* Matches resp. VRS = 000b, 001b, 010b, 011b */ |
| 38 | 2500000, 2048000, 1800000, 1500000, |
| 39 | }; |
| 40 | |
| 41 | static int stm32_vrefbuf_enable(struct regulator_dev *rdev) |
| 42 | { |
| 43 | struct stm32_vrefbuf *priv = rdev_get_drvdata(rdev); |
Fabrice Gasnier | be5295f | 2019-02-28 11:45:18 +0100 | [diff] [blame] | 44 | u32 val; |
Fabrice Gasnier | 0cdbf48 | 2017-08-30 17:55:28 +0200 | [diff] [blame] | 45 | int ret; |
| 46 | |
Minghao Chi | bfb5711 | 2022-04-12 07:10:30 +0000 | [diff] [blame] | 47 | ret = pm_runtime_resume_and_get(priv->dev); |
| 48 | if (ret < 0) |
Fabrice Gasnier | be5295f | 2019-02-28 11:45:18 +0100 | [diff] [blame] | 49 | return ret; |
Fabrice Gasnier | be5295f | 2019-02-28 11:45:18 +0100 | [diff] [blame] | 50 | |
| 51 | val = readl_relaxed(priv->base + STM32_VREFBUF_CSR); |
Fabrice Gasnier | 0cdbf48 | 2017-08-30 17:55:28 +0200 | [diff] [blame] | 52 | val = (val & ~STM32_HIZ) | STM32_ENVR; |
| 53 | writel_relaxed(val, priv->base + STM32_VREFBUF_CSR); |
| 54 | |
| 55 | /* |
| 56 | * Vrefbuf startup time depends on external capacitor: wait here for |
| 57 | * VRR to be set. That means output has reached expected value. |
| 58 | * ~650us sleep should be enough for caps up to 1.5uF. Use 10ms as |
| 59 | * arbitrary timeout. |
| 60 | */ |
| 61 | ret = readl_poll_timeout(priv->base + STM32_VREFBUF_CSR, val, |
Fabrice Gasnier | f63248f | 2018-02-08 14:43:05 +0100 | [diff] [blame] | 62 | val & STM32_VRR, 650, 10000); |
Fabrice Gasnier | 0cdbf48 | 2017-08-30 17:55:28 +0200 | [diff] [blame] | 63 | if (ret) { |
| 64 | dev_err(&rdev->dev, "stm32 vrefbuf timed out!\n"); |
| 65 | val = readl_relaxed(priv->base + STM32_VREFBUF_CSR); |
| 66 | val = (val & ~STM32_ENVR) | STM32_HIZ; |
| 67 | writel_relaxed(val, priv->base + STM32_VREFBUF_CSR); |
| 68 | } |
| 69 | |
Fabrice Gasnier | be5295f | 2019-02-28 11:45:18 +0100 | [diff] [blame] | 70 | pm_runtime_mark_last_busy(priv->dev); |
| 71 | pm_runtime_put_autosuspend(priv->dev); |
| 72 | |
Fabrice Gasnier | 0cdbf48 | 2017-08-30 17:55:28 +0200 | [diff] [blame] | 73 | return ret; |
| 74 | } |
| 75 | |
| 76 | static int stm32_vrefbuf_disable(struct regulator_dev *rdev) |
| 77 | { |
| 78 | struct stm32_vrefbuf *priv = rdev_get_drvdata(rdev); |
Fabrice Gasnier | be5295f | 2019-02-28 11:45:18 +0100 | [diff] [blame] | 79 | u32 val; |
| 80 | int ret; |
Fabrice Gasnier | 0cdbf48 | 2017-08-30 17:55:28 +0200 | [diff] [blame] | 81 | |
Minghao Chi | bfb5711 | 2022-04-12 07:10:30 +0000 | [diff] [blame] | 82 | ret = pm_runtime_resume_and_get(priv->dev); |
| 83 | if (ret < 0) |
Fabrice Gasnier | be5295f | 2019-02-28 11:45:18 +0100 | [diff] [blame] | 84 | return ret; |
Fabrice Gasnier | be5295f | 2019-02-28 11:45:18 +0100 | [diff] [blame] | 85 | |
| 86 | val = readl_relaxed(priv->base + STM32_VREFBUF_CSR); |
Fabrice Gasnier | 02fbabd | 2020-03-04 09:55:32 +0100 | [diff] [blame] | 87 | val &= ~STM32_ENVR; |
Fabrice Gasnier | 0cdbf48 | 2017-08-30 17:55:28 +0200 | [diff] [blame] | 88 | writel_relaxed(val, priv->base + STM32_VREFBUF_CSR); |
| 89 | |
Fabrice Gasnier | be5295f | 2019-02-28 11:45:18 +0100 | [diff] [blame] | 90 | pm_runtime_mark_last_busy(priv->dev); |
| 91 | pm_runtime_put_autosuspend(priv->dev); |
| 92 | |
Fabrice Gasnier | 0cdbf48 | 2017-08-30 17:55:28 +0200 | [diff] [blame] | 93 | return 0; |
| 94 | } |
| 95 | |
| 96 | static int stm32_vrefbuf_is_enabled(struct regulator_dev *rdev) |
| 97 | { |
| 98 | struct stm32_vrefbuf *priv = rdev_get_drvdata(rdev); |
Fabrice Gasnier | be5295f | 2019-02-28 11:45:18 +0100 | [diff] [blame] | 99 | int ret; |
Fabrice Gasnier | 0cdbf48 | 2017-08-30 17:55:28 +0200 | [diff] [blame] | 100 | |
Minghao Chi | bfb5711 | 2022-04-12 07:10:30 +0000 | [diff] [blame] | 101 | ret = pm_runtime_resume_and_get(priv->dev); |
| 102 | if (ret < 0) |
Fabrice Gasnier | be5295f | 2019-02-28 11:45:18 +0100 | [diff] [blame] | 103 | return ret; |
Fabrice Gasnier | be5295f | 2019-02-28 11:45:18 +0100 | [diff] [blame] | 104 | |
| 105 | ret = readl_relaxed(priv->base + STM32_VREFBUF_CSR) & STM32_ENVR; |
| 106 | |
| 107 | pm_runtime_mark_last_busy(priv->dev); |
| 108 | pm_runtime_put_autosuspend(priv->dev); |
| 109 | |
| 110 | return ret; |
Fabrice Gasnier | 0cdbf48 | 2017-08-30 17:55:28 +0200 | [diff] [blame] | 111 | } |
| 112 | |
| 113 | static int stm32_vrefbuf_set_voltage_sel(struct regulator_dev *rdev, |
| 114 | unsigned sel) |
| 115 | { |
| 116 | struct stm32_vrefbuf *priv = rdev_get_drvdata(rdev); |
Fabrice Gasnier | be5295f | 2019-02-28 11:45:18 +0100 | [diff] [blame] | 117 | u32 val; |
| 118 | int ret; |
Fabrice Gasnier | 0cdbf48 | 2017-08-30 17:55:28 +0200 | [diff] [blame] | 119 | |
Minghao Chi | bfb5711 | 2022-04-12 07:10:30 +0000 | [diff] [blame] | 120 | ret = pm_runtime_resume_and_get(priv->dev); |
| 121 | if (ret < 0) |
Fabrice Gasnier | be5295f | 2019-02-28 11:45:18 +0100 | [diff] [blame] | 122 | return ret; |
Fabrice Gasnier | be5295f | 2019-02-28 11:45:18 +0100 | [diff] [blame] | 123 | |
| 124 | val = readl_relaxed(priv->base + STM32_VREFBUF_CSR); |
Fabrice Gasnier | 0cdbf48 | 2017-08-30 17:55:28 +0200 | [diff] [blame] | 125 | val = (val & ~STM32_VRS) | FIELD_PREP(STM32_VRS, sel); |
| 126 | writel_relaxed(val, priv->base + STM32_VREFBUF_CSR); |
| 127 | |
Fabrice Gasnier | be5295f | 2019-02-28 11:45:18 +0100 | [diff] [blame] | 128 | pm_runtime_mark_last_busy(priv->dev); |
| 129 | pm_runtime_put_autosuspend(priv->dev); |
| 130 | |
Fabrice Gasnier | 0cdbf48 | 2017-08-30 17:55:28 +0200 | [diff] [blame] | 131 | return 0; |
| 132 | } |
| 133 | |
| 134 | static int stm32_vrefbuf_get_voltage_sel(struct regulator_dev *rdev) |
| 135 | { |
| 136 | struct stm32_vrefbuf *priv = rdev_get_drvdata(rdev); |
Fabrice Gasnier | be5295f | 2019-02-28 11:45:18 +0100 | [diff] [blame] | 137 | u32 val; |
| 138 | int ret; |
Fabrice Gasnier | 0cdbf48 | 2017-08-30 17:55:28 +0200 | [diff] [blame] | 139 | |
Minghao Chi | bfb5711 | 2022-04-12 07:10:30 +0000 | [diff] [blame] | 140 | ret = pm_runtime_resume_and_get(priv->dev); |
| 141 | if (ret < 0) |
Fabrice Gasnier | be5295f | 2019-02-28 11:45:18 +0100 | [diff] [blame] | 142 | return ret; |
Fabrice Gasnier | be5295f | 2019-02-28 11:45:18 +0100 | [diff] [blame] | 143 | |
| 144 | val = readl_relaxed(priv->base + STM32_VREFBUF_CSR); |
| 145 | ret = FIELD_GET(STM32_VRS, val); |
| 146 | |
| 147 | pm_runtime_mark_last_busy(priv->dev); |
| 148 | pm_runtime_put_autosuspend(priv->dev); |
| 149 | |
| 150 | return ret; |
Fabrice Gasnier | 0cdbf48 | 2017-08-30 17:55:28 +0200 | [diff] [blame] | 151 | } |
| 152 | |
| 153 | static const struct regulator_ops stm32_vrefbuf_volt_ops = { |
| 154 | .enable = stm32_vrefbuf_enable, |
| 155 | .disable = stm32_vrefbuf_disable, |
| 156 | .is_enabled = stm32_vrefbuf_is_enabled, |
| 157 | .get_voltage_sel = stm32_vrefbuf_get_voltage_sel, |
| 158 | .set_voltage_sel = stm32_vrefbuf_set_voltage_sel, |
| 159 | .list_voltage = regulator_list_voltage_table, |
| 160 | }; |
| 161 | |
| 162 | static const struct regulator_desc stm32_vrefbuf_regu = { |
| 163 | .name = "vref", |
| 164 | .supply_name = "vdda", |
| 165 | .volt_table = stm32_vrefbuf_voltages, |
| 166 | .n_voltages = ARRAY_SIZE(stm32_vrefbuf_voltages), |
| 167 | .ops = &stm32_vrefbuf_volt_ops, |
Fabrice Gasnier | 02fbabd | 2020-03-04 09:55:32 +0100 | [diff] [blame] | 168 | .off_on_delay = 1000, |
Fabrice Gasnier | 0cdbf48 | 2017-08-30 17:55:28 +0200 | [diff] [blame] | 169 | .type = REGULATOR_VOLTAGE, |
| 170 | .owner = THIS_MODULE, |
| 171 | }; |
| 172 | |
| 173 | static int stm32_vrefbuf_probe(struct platform_device *pdev) |
| 174 | { |
Fabrice Gasnier | 0cdbf48 | 2017-08-30 17:55:28 +0200 | [diff] [blame] | 175 | struct stm32_vrefbuf *priv; |
| 176 | struct regulator_config config = { }; |
| 177 | struct regulator_dev *rdev; |
| 178 | int ret; |
| 179 | |
| 180 | priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL); |
| 181 | if (!priv) |
| 182 | return -ENOMEM; |
Fabrice Gasnier | be5295f | 2019-02-28 11:45:18 +0100 | [diff] [blame] | 183 | priv->dev = &pdev->dev; |
Fabrice Gasnier | 0cdbf48 | 2017-08-30 17:55:28 +0200 | [diff] [blame] | 184 | |
YueHaibing | 73511a9 | 2019-10-09 23:01:38 +0800 | [diff] [blame] | 185 | priv->base = devm_platform_ioremap_resource(pdev, 0); |
Fabrice Gasnier | 0cdbf48 | 2017-08-30 17:55:28 +0200 | [diff] [blame] | 186 | if (IS_ERR(priv->base)) |
| 187 | return PTR_ERR(priv->base); |
| 188 | |
| 189 | priv->clk = devm_clk_get(&pdev->dev, NULL); |
| 190 | if (IS_ERR(priv->clk)) |
| 191 | return PTR_ERR(priv->clk); |
| 192 | |
Fabrice Gasnier | be5295f | 2019-02-28 11:45:18 +0100 | [diff] [blame] | 193 | pm_runtime_get_noresume(&pdev->dev); |
| 194 | pm_runtime_set_active(&pdev->dev); |
| 195 | pm_runtime_set_autosuspend_delay(&pdev->dev, |
| 196 | STM32_VREFBUF_AUTO_SUSPEND_DELAY_MS); |
| 197 | pm_runtime_use_autosuspend(&pdev->dev); |
| 198 | pm_runtime_enable(&pdev->dev); |
| 199 | |
Fabrice Gasnier | 0cdbf48 | 2017-08-30 17:55:28 +0200 | [diff] [blame] | 200 | ret = clk_prepare_enable(priv->clk); |
| 201 | if (ret) { |
| 202 | dev_err(&pdev->dev, "clk prepare failed with error %d\n", ret); |
Fabrice Gasnier | be5295f | 2019-02-28 11:45:18 +0100 | [diff] [blame] | 203 | goto err_pm_stop; |
Fabrice Gasnier | 0cdbf48 | 2017-08-30 17:55:28 +0200 | [diff] [blame] | 204 | } |
| 205 | |
| 206 | config.dev = &pdev->dev; |
| 207 | config.driver_data = priv; |
| 208 | config.of_node = pdev->dev.of_node; |
| 209 | config.init_data = of_get_regulator_init_data(&pdev->dev, |
| 210 | pdev->dev.of_node, |
| 211 | &stm32_vrefbuf_regu); |
| 212 | |
ChiYuan Huang | 8f3cbcd | 2022-12-06 15:22:21 +0800 | [diff] [blame] | 213 | rdev = regulator_register(&pdev->dev, &stm32_vrefbuf_regu, &config); |
Fabrice Gasnier | 0cdbf48 | 2017-08-30 17:55:28 +0200 | [diff] [blame] | 214 | if (IS_ERR(rdev)) { |
| 215 | ret = PTR_ERR(rdev); |
| 216 | dev_err(&pdev->dev, "register failed with error %d\n", ret); |
| 217 | goto err_clk_dis; |
| 218 | } |
| 219 | platform_set_drvdata(pdev, rdev); |
| 220 | |
Fabrice Gasnier | be5295f | 2019-02-28 11:45:18 +0100 | [diff] [blame] | 221 | pm_runtime_mark_last_busy(&pdev->dev); |
| 222 | pm_runtime_put_autosuspend(&pdev->dev); |
| 223 | |
Fabrice Gasnier | 0cdbf48 | 2017-08-30 17:55:28 +0200 | [diff] [blame] | 224 | return 0; |
| 225 | |
| 226 | err_clk_dis: |
| 227 | clk_disable_unprepare(priv->clk); |
Fabrice Gasnier | be5295f | 2019-02-28 11:45:18 +0100 | [diff] [blame] | 228 | err_pm_stop: |
| 229 | pm_runtime_disable(&pdev->dev); |
| 230 | pm_runtime_set_suspended(&pdev->dev); |
| 231 | pm_runtime_put_noidle(&pdev->dev); |
Fabrice Gasnier | 0cdbf48 | 2017-08-30 17:55:28 +0200 | [diff] [blame] | 232 | |
| 233 | return ret; |
| 234 | } |
| 235 | |
| 236 | static int stm32_vrefbuf_remove(struct platform_device *pdev) |
| 237 | { |
| 238 | struct regulator_dev *rdev = platform_get_drvdata(pdev); |
| 239 | struct stm32_vrefbuf *priv = rdev_get_drvdata(rdev); |
| 240 | |
Fabrice Gasnier | be5295f | 2019-02-28 11:45:18 +0100 | [diff] [blame] | 241 | pm_runtime_get_sync(&pdev->dev); |
Fabrice Gasnier | 0cdbf48 | 2017-08-30 17:55:28 +0200 | [diff] [blame] | 242 | regulator_unregister(rdev); |
| 243 | clk_disable_unprepare(priv->clk); |
Fabrice Gasnier | be5295f | 2019-02-28 11:45:18 +0100 | [diff] [blame] | 244 | pm_runtime_disable(&pdev->dev); |
| 245 | pm_runtime_set_suspended(&pdev->dev); |
| 246 | pm_runtime_put_noidle(&pdev->dev); |
| 247 | |
| 248 | return 0; |
| 249 | }; |
| 250 | |
| 251 | static int __maybe_unused stm32_vrefbuf_runtime_suspend(struct device *dev) |
| 252 | { |
| 253 | struct regulator_dev *rdev = dev_get_drvdata(dev); |
| 254 | struct stm32_vrefbuf *priv = rdev_get_drvdata(rdev); |
| 255 | |
| 256 | clk_disable_unprepare(priv->clk); |
Fabrice Gasnier | 0cdbf48 | 2017-08-30 17:55:28 +0200 | [diff] [blame] | 257 | |
| 258 | return 0; |
Fabrice Gasnier | be5295f | 2019-02-28 11:45:18 +0100 | [diff] [blame] | 259 | } |
| 260 | |
| 261 | static int __maybe_unused stm32_vrefbuf_runtime_resume(struct device *dev) |
| 262 | { |
| 263 | struct regulator_dev *rdev = dev_get_drvdata(dev); |
| 264 | struct stm32_vrefbuf *priv = rdev_get_drvdata(rdev); |
| 265 | |
| 266 | return clk_prepare_enable(priv->clk); |
| 267 | } |
| 268 | |
| 269 | static const struct dev_pm_ops stm32_vrefbuf_pm_ops = { |
| 270 | SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend, |
| 271 | pm_runtime_force_resume) |
| 272 | SET_RUNTIME_PM_OPS(stm32_vrefbuf_runtime_suspend, |
| 273 | stm32_vrefbuf_runtime_resume, |
| 274 | NULL) |
Fabrice Gasnier | 0cdbf48 | 2017-08-30 17:55:28 +0200 | [diff] [blame] | 275 | }; |
| 276 | |
Jisheng Zhang | d5579e7 | 2020-08-21 11:17:55 +0800 | [diff] [blame] | 277 | static const struct of_device_id __maybe_unused stm32_vrefbuf_of_match[] = { |
Fabrice Gasnier | 0cdbf48 | 2017-08-30 17:55:28 +0200 | [diff] [blame] | 278 | { .compatible = "st,stm32-vrefbuf", }, |
| 279 | {}, |
| 280 | }; |
| 281 | MODULE_DEVICE_TABLE(of, stm32_vrefbuf_of_match); |
| 282 | |
| 283 | static struct platform_driver stm32_vrefbuf_driver = { |
| 284 | .probe = stm32_vrefbuf_probe, |
| 285 | .remove = stm32_vrefbuf_remove, |
| 286 | .driver = { |
| 287 | .name = "stm32-vrefbuf", |
| 288 | .of_match_table = of_match_ptr(stm32_vrefbuf_of_match), |
Fabrice Gasnier | be5295f | 2019-02-28 11:45:18 +0100 | [diff] [blame] | 289 | .pm = &stm32_vrefbuf_pm_ops, |
Fabrice Gasnier | 0cdbf48 | 2017-08-30 17:55:28 +0200 | [diff] [blame] | 290 | }, |
| 291 | }; |
| 292 | module_platform_driver(stm32_vrefbuf_driver); |
| 293 | |
| 294 | MODULE_LICENSE("GPL v2"); |
| 295 | MODULE_AUTHOR("Fabrice Gasnier <fabrice.gasnier@st.com>"); |
| 296 | MODULE_DESCRIPTION("STMicroelectronics STM32 VREFBUF driver"); |
| 297 | MODULE_ALIAS("platform:stm32-vrefbuf"); |