1 /* 2 * Freescale Vybrid vf610 DAC driver 3 * 4 * Copyright 2016 Toradex AG 5 * 6 * This program is free software; you can redistribute it and/or modify 7 * it under the terms of the GNU General Public License as published by 8 * the Free Software Foundation; either version 2 of the License, or 9 * (at your option) any later version. 10 * 11 * This program is distributed in the hope that it will be useful, 12 * but WITHOUT ANY WARRANTY; without even the implied warranty of 13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 14 * GNU General Public License for more details. 15 */ 16 17 #include <linux/clk.h> 18 #include <linux/err.h> 19 #include <linux/interrupt.h> 20 #include <linux/io.h> 21 #include <linux/kernel.h> 22 #include <linux/module.h> 23 #include <linux/platform_device.h> 24 #include <linux/regulator/consumer.h> 25 #include <linux/slab.h> 26 27 #include <linux/iio/iio.h> 28 #include <linux/iio/sysfs.h> 29 30 #define VF610_DACx_STATCTRL 0x20 31 32 #define VF610_DAC_DACEN BIT(15) 33 #define VF610_DAC_DACRFS BIT(14) 34 #define VF610_DAC_LPEN BIT(11) 35 36 #define VF610_DAC_DAT0(x) ((x) & 0xFFF) 37 38 enum vf610_conversion_mode_sel { 39 VF610_DAC_CONV_HIGH_POWER, 40 VF610_DAC_CONV_LOW_POWER, 41 }; 42 43 struct vf610_dac { 44 struct clk *clk; 45 struct device *dev; 46 enum vf610_conversion_mode_sel conv_mode; 47 void __iomem *regs; 48 }; 49 50 static void vf610_dac_init(struct vf610_dac *info) 51 { 52 int val; 53 54 info->conv_mode = VF610_DAC_CONV_LOW_POWER; 55 val = VF610_DAC_DACEN | VF610_DAC_DACRFS | 56 VF610_DAC_LPEN; 57 writel(val, info->regs + VF610_DACx_STATCTRL); 58 } 59 60 static void vf610_dac_exit(struct vf610_dac *info) 61 { 62 int val; 63 64 val = readl(info->regs + VF610_DACx_STATCTRL); 65 val &= ~VF610_DAC_DACEN; 66 writel(val, info->regs + VF610_DACx_STATCTRL); 67 } 68 69 static int vf610_set_conversion_mode(struct iio_dev *indio_dev, 70 const struct iio_chan_spec *chan, 71 unsigned int mode) 72 { 73 struct vf610_dac *info = iio_priv(indio_dev); 74 int val; 75 76 mutex_lock(&indio_dev->mlock); 77 info->conv_mode = mode; 78 val = readl(info->regs + VF610_DACx_STATCTRL); 79 if (mode) 80 val |= VF610_DAC_LPEN; 81 else 82 val &= ~VF610_DAC_LPEN; 83 writel(val, info->regs + VF610_DACx_STATCTRL); 84 mutex_unlock(&indio_dev->mlock); 85 86 return 0; 87 } 88 89 static int vf610_get_conversion_mode(struct iio_dev *indio_dev, 90 const struct iio_chan_spec *chan) 91 { 92 struct vf610_dac *info = iio_priv(indio_dev); 93 94 return info->conv_mode; 95 } 96 97 static const char * const vf610_conv_modes[] = { "high-power", "low-power" }; 98 99 static const struct iio_enum vf610_conversion_mode = { 100 .items = vf610_conv_modes, 101 .num_items = ARRAY_SIZE(vf610_conv_modes), 102 .get = vf610_get_conversion_mode, 103 .set = vf610_set_conversion_mode, 104 }; 105 106 static const struct iio_chan_spec_ext_info vf610_ext_info[] = { 107 IIO_ENUM("conversion_mode", IIO_SHARED_BY_DIR, 108 &vf610_conversion_mode), 109 {}, 110 }; 111 112 #define VF610_DAC_CHAN(_chan_type) { \ 113 .type = (_chan_type), \ 114 .output = 1, \ 115 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \ 116 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \ 117 .ext_info = vf610_ext_info, \ 118 } 119 120 static const struct iio_chan_spec vf610_dac_iio_channels[] = { 121 VF610_DAC_CHAN(IIO_VOLTAGE), 122 }; 123 124 static int vf610_read_raw(struct iio_dev *indio_dev, 125 struct iio_chan_spec const *chan, 126 int *val, int *val2, 127 long mask) 128 { 129 struct vf610_dac *info = iio_priv(indio_dev); 130 131 switch (mask) { 132 case IIO_CHAN_INFO_RAW: 133 *val = VF610_DAC_DAT0(readl(info->regs)); 134 return IIO_VAL_INT; 135 case IIO_CHAN_INFO_SCALE: 136 /* 137 * DACRFS is always 1 for valid reference and typical 138 * reference voltage as per Vybrid datasheet is 3.3V 139 * from section 9.1.2.1 of Vybrid datasheet 140 */ 141 *val = 3300 /* mV */; 142 *val2 = 12; 143 return IIO_VAL_FRACTIONAL_LOG2; 144 145 default: 146 return -EINVAL; 147 } 148 } 149 150 static int vf610_write_raw(struct iio_dev *indio_dev, 151 struct iio_chan_spec const *chan, 152 int val, int val2, 153 long mask) 154 { 155 struct vf610_dac *info = iio_priv(indio_dev); 156 157 switch (mask) { 158 case IIO_CHAN_INFO_RAW: 159 mutex_lock(&indio_dev->mlock); 160 writel(VF610_DAC_DAT0(val), info->regs); 161 mutex_unlock(&indio_dev->mlock); 162 return 0; 163 164 default: 165 return -EINVAL; 166 } 167 } 168 169 static const struct iio_info vf610_dac_iio_info = { 170 .read_raw = &vf610_read_raw, 171 .write_raw = &vf610_write_raw, 172 }; 173 174 static const struct of_device_id vf610_dac_match[] = { 175 { .compatible = "fsl,vf610-dac", }, 176 { /* sentinel */ } 177 }; 178 MODULE_DEVICE_TABLE(of, vf610_dac_match); 179 180 static int vf610_dac_probe(struct platform_device *pdev) 181 { 182 struct iio_dev *indio_dev; 183 struct vf610_dac *info; 184 struct resource *mem; 185 int ret; 186 187 indio_dev = devm_iio_device_alloc(&pdev->dev, 188 sizeof(struct vf610_dac)); 189 if (!indio_dev) { 190 dev_err(&pdev->dev, "Failed allocating iio device\n"); 191 return -ENOMEM; 192 } 193 194 info = iio_priv(indio_dev); 195 info->dev = &pdev->dev; 196 197 mem = platform_get_resource(pdev, IORESOURCE_MEM, 0); 198 info->regs = devm_ioremap_resource(&pdev->dev, mem); 199 if (IS_ERR(info->regs)) 200 return PTR_ERR(info->regs); 201 202 info->clk = devm_clk_get(&pdev->dev, "dac"); 203 if (IS_ERR(info->clk)) { 204 dev_err(&pdev->dev, "Failed getting clock, err = %ld\n", 205 PTR_ERR(info->clk)); 206 return PTR_ERR(info->clk); 207 } 208 209 platform_set_drvdata(pdev, indio_dev); 210 211 indio_dev->name = dev_name(&pdev->dev); 212 indio_dev->dev.parent = &pdev->dev; 213 indio_dev->dev.of_node = pdev->dev.of_node; 214 indio_dev->info = &vf610_dac_iio_info; 215 indio_dev->modes = INDIO_DIRECT_MODE; 216 indio_dev->channels = vf610_dac_iio_channels; 217 indio_dev->num_channels = ARRAY_SIZE(vf610_dac_iio_channels); 218 219 ret = clk_prepare_enable(info->clk); 220 if (ret) { 221 dev_err(&pdev->dev, 222 "Could not prepare or enable the clock\n"); 223 return ret; 224 } 225 226 vf610_dac_init(info); 227 228 ret = iio_device_register(indio_dev); 229 if (ret) { 230 dev_err(&pdev->dev, "Couldn't register the device\n"); 231 goto error_iio_device_register; 232 } 233 234 return 0; 235 236 error_iio_device_register: 237 clk_disable_unprepare(info->clk); 238 239 return ret; 240 } 241 242 static int vf610_dac_remove(struct platform_device *pdev) 243 { 244 struct iio_dev *indio_dev = platform_get_drvdata(pdev); 245 struct vf610_dac *info = iio_priv(indio_dev); 246 247 iio_device_unregister(indio_dev); 248 vf610_dac_exit(info); 249 clk_disable_unprepare(info->clk); 250 251 return 0; 252 } 253 254 #ifdef CONFIG_PM_SLEEP 255 static int vf610_dac_suspend(struct device *dev) 256 { 257 struct iio_dev *indio_dev = dev_get_drvdata(dev); 258 struct vf610_dac *info = iio_priv(indio_dev); 259 260 vf610_dac_exit(info); 261 clk_disable_unprepare(info->clk); 262 263 return 0; 264 } 265 266 static int vf610_dac_resume(struct device *dev) 267 { 268 struct iio_dev *indio_dev = dev_get_drvdata(dev); 269 struct vf610_dac *info = iio_priv(indio_dev); 270 int ret; 271 272 ret = clk_prepare_enable(info->clk); 273 if (ret) 274 return ret; 275 276 vf610_dac_init(info); 277 278 return 0; 279 } 280 #endif 281 282 static SIMPLE_DEV_PM_OPS(vf610_dac_pm_ops, vf610_dac_suspend, vf610_dac_resume); 283 284 static struct platform_driver vf610_dac_driver = { 285 .probe = vf610_dac_probe, 286 .remove = vf610_dac_remove, 287 .driver = { 288 .name = "vf610-dac", 289 .of_match_table = vf610_dac_match, 290 .pm = &vf610_dac_pm_ops, 291 }, 292 }; 293 module_platform_driver(vf610_dac_driver); 294 295 MODULE_AUTHOR("Sanchayan Maity <sanchayan.maity@toradex.com>"); 296 MODULE_DESCRIPTION("Freescale VF610 DAC driver"); 297 MODULE_LICENSE("GPL v2"); 298