1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * This file is part of STM32 DAC driver 4 * 5 * Copyright (C) 2017, STMicroelectronics - All Rights Reserved 6 * Author: Fabrice Gasnier <fabrice.gasnier@st.com>. 7 * 8 */ 9 10 #include <linux/clk.h> 11 #include <linux/delay.h> 12 #include <linux/module.h> 13 #include <linux/of_platform.h> 14 #include <linux/pm_runtime.h> 15 #include <linux/regulator/consumer.h> 16 #include <linux/reset.h> 17 18 #include "stm32-dac-core.h" 19 20 /** 21 * struct stm32_dac_priv - stm32 DAC core private data 22 * @pclk: peripheral clock common for all DACs 23 * @vref: regulator reference 24 * @common: Common data for all DAC instances 25 */ 26 struct stm32_dac_priv { 27 struct clk *pclk; 28 struct regulator *vref; 29 struct stm32_dac_common common; 30 }; 31 32 /** 33 * struct stm32_dac_cfg - DAC configuration 34 * @has_hfsel: DAC has high frequency control 35 */ 36 struct stm32_dac_cfg { 37 bool has_hfsel; 38 }; 39 40 static struct stm32_dac_priv *to_stm32_dac_priv(struct stm32_dac_common *com) 41 { 42 return container_of(com, struct stm32_dac_priv, common); 43 } 44 45 static const struct regmap_config stm32_dac_regmap_cfg = { 46 .reg_bits = 32, 47 .val_bits = 32, 48 .reg_stride = sizeof(u32), 49 .max_register = 0x3fc, 50 }; 51 52 static int stm32_dac_core_hw_start(struct device *dev) 53 { 54 struct stm32_dac_common *common = dev_get_drvdata(dev); 55 struct stm32_dac_priv *priv = to_stm32_dac_priv(common); 56 int ret; 57 58 ret = regulator_enable(priv->vref); 59 if (ret < 0) { 60 dev_err(dev, "vref enable failed: %d\n", ret); 61 return ret; 62 } 63 64 ret = clk_prepare_enable(priv->pclk); 65 if (ret < 0) { 66 dev_err(dev, "pclk enable failed: %d\n", ret); 67 goto err_regulator_disable; 68 } 69 70 return 0; 71 72 err_regulator_disable: 73 regulator_disable(priv->vref); 74 75 return ret; 76 } 77 78 static void stm32_dac_core_hw_stop(struct device *dev) 79 { 80 struct stm32_dac_common *common = dev_get_drvdata(dev); 81 struct stm32_dac_priv *priv = to_stm32_dac_priv(common); 82 83 clk_disable_unprepare(priv->pclk); 84 regulator_disable(priv->vref); 85 } 86 87 static int stm32_dac_probe(struct platform_device *pdev) 88 { 89 struct device *dev = &pdev->dev; 90 const struct stm32_dac_cfg *cfg; 91 struct stm32_dac_priv *priv; 92 struct regmap *regmap; 93 struct resource *res; 94 void __iomem *mmio; 95 struct reset_control *rst; 96 int ret; 97 98 if (!dev->of_node) 99 return -ENODEV; 100 101 priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL); 102 if (!priv) 103 return -ENOMEM; 104 platform_set_drvdata(pdev, &priv->common); 105 106 cfg = (const struct stm32_dac_cfg *) 107 of_match_device(dev->driver->of_match_table, dev)->data; 108 109 res = platform_get_resource(pdev, IORESOURCE_MEM, 0); 110 mmio = devm_ioremap_resource(dev, res); 111 if (IS_ERR(mmio)) 112 return PTR_ERR(mmio); 113 114 regmap = devm_regmap_init_mmio_clk(dev, "pclk", mmio, 115 &stm32_dac_regmap_cfg); 116 if (IS_ERR(regmap)) 117 return PTR_ERR(regmap); 118 priv->common.regmap = regmap; 119 120 priv->pclk = devm_clk_get(dev, "pclk"); 121 if (IS_ERR(priv->pclk)) { 122 ret = PTR_ERR(priv->pclk); 123 dev_err(dev, "pclk get failed\n"); 124 return ret; 125 } 126 127 priv->vref = devm_regulator_get(dev, "vref"); 128 if (IS_ERR(priv->vref)) { 129 ret = PTR_ERR(priv->vref); 130 dev_err(dev, "vref get failed, %d\n", ret); 131 return ret; 132 } 133 134 pm_runtime_get_noresume(dev); 135 pm_runtime_set_active(dev); 136 pm_runtime_enable(dev); 137 138 ret = stm32_dac_core_hw_start(dev); 139 if (ret) 140 goto err_pm_stop; 141 142 ret = regulator_get_voltage(priv->vref); 143 if (ret < 0) { 144 dev_err(dev, "vref get voltage failed, %d\n", ret); 145 goto err_hw_stop; 146 } 147 priv->common.vref_mv = ret / 1000; 148 dev_dbg(dev, "vref+=%dmV\n", priv->common.vref_mv); 149 150 rst = devm_reset_control_get_optional_exclusive(dev, NULL); 151 if (rst) { 152 if (IS_ERR(rst)) { 153 ret = dev_err_probe(dev, PTR_ERR(rst), "reset get failed\n"); 154 goto err_hw_stop; 155 } 156 157 reset_control_assert(rst); 158 udelay(2); 159 reset_control_deassert(rst); 160 } 161 162 if (cfg && cfg->has_hfsel) { 163 /* When clock speed is higher than 80MHz, set HFSEL */ 164 priv->common.hfsel = (clk_get_rate(priv->pclk) > 80000000UL); 165 ret = regmap_update_bits(regmap, STM32_DAC_CR, 166 STM32H7_DAC_CR_HFSEL, 167 priv->common.hfsel ? 168 STM32H7_DAC_CR_HFSEL : 0); 169 if (ret) 170 goto err_hw_stop; 171 } 172 173 174 ret = of_platform_populate(pdev->dev.of_node, NULL, NULL, dev); 175 if (ret < 0) { 176 dev_err(dev, "failed to populate DT children\n"); 177 goto err_hw_stop; 178 } 179 180 pm_runtime_put(dev); 181 182 return 0; 183 184 err_hw_stop: 185 stm32_dac_core_hw_stop(dev); 186 err_pm_stop: 187 pm_runtime_disable(dev); 188 pm_runtime_set_suspended(dev); 189 pm_runtime_put_noidle(dev); 190 191 return ret; 192 } 193 194 static int stm32_dac_remove(struct platform_device *pdev) 195 { 196 pm_runtime_get_sync(&pdev->dev); 197 of_platform_depopulate(&pdev->dev); 198 stm32_dac_core_hw_stop(&pdev->dev); 199 pm_runtime_disable(&pdev->dev); 200 pm_runtime_set_suspended(&pdev->dev); 201 pm_runtime_put_noidle(&pdev->dev); 202 203 return 0; 204 } 205 206 static int __maybe_unused stm32_dac_core_resume(struct device *dev) 207 { 208 struct stm32_dac_common *common = dev_get_drvdata(dev); 209 struct stm32_dac_priv *priv = to_stm32_dac_priv(common); 210 int ret; 211 212 if (priv->common.hfsel) { 213 /* restore hfsel (maybe lost under low power state) */ 214 ret = regmap_update_bits(priv->common.regmap, STM32_DAC_CR, 215 STM32H7_DAC_CR_HFSEL, 216 STM32H7_DAC_CR_HFSEL); 217 if (ret) 218 return ret; 219 } 220 221 return pm_runtime_force_resume(dev); 222 } 223 224 static int __maybe_unused stm32_dac_core_runtime_suspend(struct device *dev) 225 { 226 stm32_dac_core_hw_stop(dev); 227 228 return 0; 229 } 230 231 static int __maybe_unused stm32_dac_core_runtime_resume(struct device *dev) 232 { 233 return stm32_dac_core_hw_start(dev); 234 } 235 236 static const struct dev_pm_ops stm32_dac_core_pm_ops = { 237 SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend, stm32_dac_core_resume) 238 SET_RUNTIME_PM_OPS(stm32_dac_core_runtime_suspend, 239 stm32_dac_core_runtime_resume, 240 NULL) 241 }; 242 243 static const struct stm32_dac_cfg stm32h7_dac_cfg = { 244 .has_hfsel = true, 245 }; 246 247 static const struct of_device_id stm32_dac_of_match[] = { 248 { 249 .compatible = "st,stm32f4-dac-core", 250 }, { 251 .compatible = "st,stm32h7-dac-core", 252 .data = (void *)&stm32h7_dac_cfg, 253 }, 254 {}, 255 }; 256 MODULE_DEVICE_TABLE(of, stm32_dac_of_match); 257 258 static struct platform_driver stm32_dac_driver = { 259 .probe = stm32_dac_probe, 260 .remove = stm32_dac_remove, 261 .driver = { 262 .name = "stm32-dac-core", 263 .of_match_table = stm32_dac_of_match, 264 .pm = &stm32_dac_core_pm_ops, 265 }, 266 }; 267 module_platform_driver(stm32_dac_driver); 268 269 MODULE_AUTHOR("Fabrice Gasnier <fabrice.gasnier@st.com>"); 270 MODULE_DESCRIPTION("STMicroelectronics STM32 DAC core driver"); 271 MODULE_LICENSE("GPL v2"); 272 MODULE_ALIAS("platform:stm32-dac-core"); 273