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