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 void __iomem *mmio; 94 struct reset_control *rst; 95 int ret; 96 97 if (!dev->of_node) 98 return -ENODEV; 99 100 priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL); 101 if (!priv) 102 return -ENOMEM; 103 platform_set_drvdata(pdev, &priv->common); 104 105 cfg = (const struct stm32_dac_cfg *) 106 of_match_device(dev->driver->of_match_table, dev)->data; 107 108 mmio = devm_platform_ioremap_resource(pdev, 0); 109 if (IS_ERR(mmio)) 110 return PTR_ERR(mmio); 111 112 regmap = devm_regmap_init_mmio_clk(dev, "pclk", mmio, 113 &stm32_dac_regmap_cfg); 114 if (IS_ERR(regmap)) 115 return PTR_ERR(regmap); 116 priv->common.regmap = regmap; 117 118 priv->pclk = devm_clk_get(dev, "pclk"); 119 if (IS_ERR(priv->pclk)) 120 return dev_err_probe(dev, PTR_ERR(priv->pclk), "pclk get failed\n"); 121 122 priv->vref = devm_regulator_get(dev, "vref"); 123 if (IS_ERR(priv->vref)) 124 return dev_err_probe(dev, PTR_ERR(priv->vref), "vref get failed\n"); 125 126 pm_runtime_get_noresume(dev); 127 pm_runtime_set_active(dev); 128 pm_runtime_enable(dev); 129 130 ret = stm32_dac_core_hw_start(dev); 131 if (ret) 132 goto err_pm_stop; 133 134 ret = regulator_get_voltage(priv->vref); 135 if (ret < 0) { 136 dev_err(dev, "vref get voltage failed, %d\n", ret); 137 goto err_hw_stop; 138 } 139 priv->common.vref_mv = ret / 1000; 140 dev_dbg(dev, "vref+=%dmV\n", priv->common.vref_mv); 141 142 rst = devm_reset_control_get_optional_exclusive(dev, NULL); 143 if (rst) { 144 if (IS_ERR(rst)) { 145 ret = dev_err_probe(dev, PTR_ERR(rst), "reset get failed\n"); 146 goto err_hw_stop; 147 } 148 149 reset_control_assert(rst); 150 udelay(2); 151 reset_control_deassert(rst); 152 } 153 154 if (cfg && cfg->has_hfsel) { 155 /* When clock speed is higher than 80MHz, set HFSEL */ 156 priv->common.hfsel = (clk_get_rate(priv->pclk) > 80000000UL); 157 ret = regmap_update_bits(regmap, STM32_DAC_CR, 158 STM32H7_DAC_CR_HFSEL, 159 priv->common.hfsel ? 160 STM32H7_DAC_CR_HFSEL : 0); 161 if (ret) 162 goto err_hw_stop; 163 } 164 165 166 ret = of_platform_populate(pdev->dev.of_node, NULL, NULL, dev); 167 if (ret < 0) { 168 dev_err(dev, "failed to populate DT children\n"); 169 goto err_hw_stop; 170 } 171 172 pm_runtime_put(dev); 173 174 return 0; 175 176 err_hw_stop: 177 stm32_dac_core_hw_stop(dev); 178 err_pm_stop: 179 pm_runtime_disable(dev); 180 pm_runtime_set_suspended(dev); 181 pm_runtime_put_noidle(dev); 182 183 return ret; 184 } 185 186 static int stm32_dac_remove(struct platform_device *pdev) 187 { 188 pm_runtime_get_sync(&pdev->dev); 189 of_platform_depopulate(&pdev->dev); 190 stm32_dac_core_hw_stop(&pdev->dev); 191 pm_runtime_disable(&pdev->dev); 192 pm_runtime_set_suspended(&pdev->dev); 193 pm_runtime_put_noidle(&pdev->dev); 194 195 return 0; 196 } 197 198 static int __maybe_unused stm32_dac_core_resume(struct device *dev) 199 { 200 struct stm32_dac_common *common = dev_get_drvdata(dev); 201 struct stm32_dac_priv *priv = to_stm32_dac_priv(common); 202 int ret; 203 204 if (priv->common.hfsel) { 205 /* restore hfsel (maybe lost under low power state) */ 206 ret = regmap_update_bits(priv->common.regmap, STM32_DAC_CR, 207 STM32H7_DAC_CR_HFSEL, 208 STM32H7_DAC_CR_HFSEL); 209 if (ret) 210 return ret; 211 } 212 213 return pm_runtime_force_resume(dev); 214 } 215 216 static int __maybe_unused stm32_dac_core_runtime_suspend(struct device *dev) 217 { 218 stm32_dac_core_hw_stop(dev); 219 220 return 0; 221 } 222 223 static int __maybe_unused stm32_dac_core_runtime_resume(struct device *dev) 224 { 225 return stm32_dac_core_hw_start(dev); 226 } 227 228 static const struct dev_pm_ops stm32_dac_core_pm_ops = { 229 SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend, stm32_dac_core_resume) 230 SET_RUNTIME_PM_OPS(stm32_dac_core_runtime_suspend, 231 stm32_dac_core_runtime_resume, 232 NULL) 233 }; 234 235 static const struct stm32_dac_cfg stm32h7_dac_cfg = { 236 .has_hfsel = true, 237 }; 238 239 static const struct of_device_id stm32_dac_of_match[] = { 240 { 241 .compatible = "st,stm32f4-dac-core", 242 }, { 243 .compatible = "st,stm32h7-dac-core", 244 .data = (void *)&stm32h7_dac_cfg, 245 }, 246 {}, 247 }; 248 MODULE_DEVICE_TABLE(of, stm32_dac_of_match); 249 250 static struct platform_driver stm32_dac_driver = { 251 .probe = stm32_dac_probe, 252 .remove = stm32_dac_remove, 253 .driver = { 254 .name = "stm32-dac-core", 255 .of_match_table = stm32_dac_of_match, 256 .pm = &stm32_dac_core_pm_ops, 257 }, 258 }; 259 module_platform_driver(stm32_dac_driver); 260 261 MODULE_AUTHOR("Fabrice Gasnier <fabrice.gasnier@st.com>"); 262 MODULE_DESCRIPTION("STMicroelectronics STM32 DAC core driver"); 263 MODULE_LICENSE("GPL v2"); 264 MODULE_ALIAS("platform:stm32-dac-core"); 265