1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * Freescale Vybrid vf610 DAC driver 4 * 5 * Copyright 2016 Toradex AG 6 */ 7 8 #include <linux/clk.h> 9 #include <linux/err.h> 10 #include <linux/interrupt.h> 11 #include <linux/io.h> 12 #include <linux/kernel.h> 13 #include <linux/mod_devicetable.h> 14 #include <linux/module.h> 15 #include <linux/platform_device.h> 16 #include <linux/regulator/consumer.h> 17 #include <linux/slab.h> 18 19 #include <linux/iio/iio.h> 20 #include <linux/iio/sysfs.h> 21 22 #define VF610_DACx_STATCTRL 0x20 23 24 #define VF610_DAC_DACEN BIT(15) 25 #define VF610_DAC_DACRFS BIT(14) 26 #define VF610_DAC_LPEN BIT(11) 27 28 #define VF610_DAC_DAT0(x) ((x) & 0xFFF) 29 30 enum vf610_conversion_mode_sel { 31 VF610_DAC_CONV_HIGH_POWER, 32 VF610_DAC_CONV_LOW_POWER, 33 }; 34 35 struct vf610_dac { 36 struct clk *clk; 37 struct device *dev; 38 enum vf610_conversion_mode_sel conv_mode; 39 void __iomem *regs; 40 struct mutex lock; 41 }; 42 43 static void vf610_dac_init(struct vf610_dac *info) 44 { 45 int val; 46 47 info->conv_mode = VF610_DAC_CONV_LOW_POWER; 48 val = VF610_DAC_DACEN | VF610_DAC_DACRFS | 49 VF610_DAC_LPEN; 50 writel(val, info->regs + VF610_DACx_STATCTRL); 51 } 52 53 static void vf610_dac_exit(struct vf610_dac *info) 54 { 55 int val; 56 57 val = readl(info->regs + VF610_DACx_STATCTRL); 58 val &= ~VF610_DAC_DACEN; 59 writel(val, info->regs + VF610_DACx_STATCTRL); 60 } 61 62 static int vf610_set_conversion_mode(struct iio_dev *indio_dev, 63 const struct iio_chan_spec *chan, 64 unsigned int mode) 65 { 66 struct vf610_dac *info = iio_priv(indio_dev); 67 int val; 68 69 mutex_lock(&info->lock); 70 info->conv_mode = mode; 71 val = readl(info->regs + VF610_DACx_STATCTRL); 72 if (mode) 73 val |= VF610_DAC_LPEN; 74 else 75 val &= ~VF610_DAC_LPEN; 76 writel(val, info->regs + VF610_DACx_STATCTRL); 77 mutex_unlock(&info->lock); 78 79 return 0; 80 } 81 82 static int vf610_get_conversion_mode(struct iio_dev *indio_dev, 83 const struct iio_chan_spec *chan) 84 { 85 struct vf610_dac *info = iio_priv(indio_dev); 86 87 return info->conv_mode; 88 } 89 90 static const char * const vf610_conv_modes[] = { "high-power", "low-power" }; 91 92 static const struct iio_enum vf610_conversion_mode = { 93 .items = vf610_conv_modes, 94 .num_items = ARRAY_SIZE(vf610_conv_modes), 95 .get = vf610_get_conversion_mode, 96 .set = vf610_set_conversion_mode, 97 }; 98 99 static const struct iio_chan_spec_ext_info vf610_ext_info[] = { 100 IIO_ENUM("conversion_mode", IIO_SHARED_BY_DIR, 101 &vf610_conversion_mode), 102 {}, 103 }; 104 105 #define VF610_DAC_CHAN(_chan_type) { \ 106 .type = (_chan_type), \ 107 .output = 1, \ 108 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \ 109 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \ 110 .ext_info = vf610_ext_info, \ 111 } 112 113 static const struct iio_chan_spec vf610_dac_iio_channels[] = { 114 VF610_DAC_CHAN(IIO_VOLTAGE), 115 }; 116 117 static int vf610_read_raw(struct iio_dev *indio_dev, 118 struct iio_chan_spec const *chan, 119 int *val, int *val2, 120 long mask) 121 { 122 struct vf610_dac *info = iio_priv(indio_dev); 123 124 switch (mask) { 125 case IIO_CHAN_INFO_RAW: 126 *val = VF610_DAC_DAT0(readl(info->regs)); 127 return IIO_VAL_INT; 128 case IIO_CHAN_INFO_SCALE: 129 /* 130 * DACRFS is always 1 for valid reference and typical 131 * reference voltage as per Vybrid datasheet is 3.3V 132 * from section 9.1.2.1 of Vybrid datasheet 133 */ 134 *val = 3300 /* mV */; 135 *val2 = 12; 136 return IIO_VAL_FRACTIONAL_LOG2; 137 138 default: 139 return -EINVAL; 140 } 141 } 142 143 static int vf610_write_raw(struct iio_dev *indio_dev, 144 struct iio_chan_spec const *chan, 145 int val, int val2, 146 long mask) 147 { 148 struct vf610_dac *info = iio_priv(indio_dev); 149 150 switch (mask) { 151 case IIO_CHAN_INFO_RAW: 152 mutex_lock(&info->lock); 153 writel(VF610_DAC_DAT0(val), info->regs); 154 mutex_unlock(&info->lock); 155 return 0; 156 157 default: 158 return -EINVAL; 159 } 160 } 161 162 static const struct iio_info vf610_dac_iio_info = { 163 .read_raw = &vf610_read_raw, 164 .write_raw = &vf610_write_raw, 165 }; 166 167 static const struct of_device_id vf610_dac_match[] = { 168 { .compatible = "fsl,vf610-dac", }, 169 { /* sentinel */ } 170 }; 171 MODULE_DEVICE_TABLE(of, vf610_dac_match); 172 173 static int vf610_dac_probe(struct platform_device *pdev) 174 { 175 struct iio_dev *indio_dev; 176 struct vf610_dac *info; 177 int ret; 178 179 indio_dev = devm_iio_device_alloc(&pdev->dev, 180 sizeof(struct vf610_dac)); 181 if (!indio_dev) { 182 dev_err(&pdev->dev, "Failed allocating iio device\n"); 183 return -ENOMEM; 184 } 185 186 info = iio_priv(indio_dev); 187 info->dev = &pdev->dev; 188 189 info->regs = devm_platform_ioremap_resource(pdev, 0); 190 if (IS_ERR(info->regs)) 191 return PTR_ERR(info->regs); 192 193 info->clk = devm_clk_get(&pdev->dev, "dac"); 194 if (IS_ERR(info->clk)) { 195 dev_err(&pdev->dev, "Failed getting clock, err = %ld\n", 196 PTR_ERR(info->clk)); 197 return PTR_ERR(info->clk); 198 } 199 200 platform_set_drvdata(pdev, indio_dev); 201 202 indio_dev->name = dev_name(&pdev->dev); 203 indio_dev->info = &vf610_dac_iio_info; 204 indio_dev->modes = INDIO_DIRECT_MODE; 205 indio_dev->channels = vf610_dac_iio_channels; 206 indio_dev->num_channels = ARRAY_SIZE(vf610_dac_iio_channels); 207 208 mutex_init(&info->lock); 209 210 ret = clk_prepare_enable(info->clk); 211 if (ret) { 212 dev_err(&pdev->dev, 213 "Could not prepare or enable the clock\n"); 214 return ret; 215 } 216 217 vf610_dac_init(info); 218 219 ret = iio_device_register(indio_dev); 220 if (ret) { 221 dev_err(&pdev->dev, "Couldn't register the device\n"); 222 goto error_iio_device_register; 223 } 224 225 return 0; 226 227 error_iio_device_register: 228 vf610_dac_exit(info); 229 clk_disable_unprepare(info->clk); 230 231 return ret; 232 } 233 234 static int vf610_dac_remove(struct platform_device *pdev) 235 { 236 struct iio_dev *indio_dev = platform_get_drvdata(pdev); 237 struct vf610_dac *info = iio_priv(indio_dev); 238 239 iio_device_unregister(indio_dev); 240 vf610_dac_exit(info); 241 clk_disable_unprepare(info->clk); 242 243 return 0; 244 } 245 246 static int vf610_dac_suspend(struct device *dev) 247 { 248 struct iio_dev *indio_dev = dev_get_drvdata(dev); 249 struct vf610_dac *info = iio_priv(indio_dev); 250 251 vf610_dac_exit(info); 252 clk_disable_unprepare(info->clk); 253 254 return 0; 255 } 256 257 static int vf610_dac_resume(struct device *dev) 258 { 259 struct iio_dev *indio_dev = dev_get_drvdata(dev); 260 struct vf610_dac *info = iio_priv(indio_dev); 261 int ret; 262 263 ret = clk_prepare_enable(info->clk); 264 if (ret) 265 return ret; 266 267 vf610_dac_init(info); 268 269 return 0; 270 } 271 272 static DEFINE_SIMPLE_DEV_PM_OPS(vf610_dac_pm_ops, vf610_dac_suspend, 273 vf610_dac_resume); 274 275 static struct platform_driver vf610_dac_driver = { 276 .probe = vf610_dac_probe, 277 .remove = vf610_dac_remove, 278 .driver = { 279 .name = "vf610-dac", 280 .of_match_table = vf610_dac_match, 281 .pm = pm_sleep_ptr(&vf610_dac_pm_ops), 282 }, 283 }; 284 module_platform_driver(vf610_dac_driver); 285 286 MODULE_AUTHOR("Sanchayan Maity <sanchayan.maity@toradex.com>"); 287 MODULE_DESCRIPTION("Freescale VF610 DAC driver"); 288 MODULE_LICENSE("GPL v2"); 289