1 /* 2 * Marvell Berlin2 ADC driver 3 * 4 * Copyright (C) 2015 Marvell Technology Group Ltd. 5 * 6 * Antoine Tenart <antoine.tenart@free-electrons.com> 7 * 8 * This file is licensed under the terms of the GNU General Public 9 * License version 2. This program is licensed "as is" without any 10 * warranty of any kind, whether express or implied. 11 */ 12 13 #include <linux/iio/iio.h> 14 #include <linux/iio/driver.h> 15 #include <linux/iio/machine.h> 16 #include <linux/interrupt.h> 17 #include <linux/kernel.h> 18 #include <linux/module.h> 19 #include <linux/platform_device.h> 20 #include <linux/slab.h> 21 #include <linux/mfd/syscon.h> 22 #include <linux/regmap.h> 23 #include <linux/sched.h> 24 #include <linux/wait.h> 25 26 #define BERLIN2_SM_CTRL 0x14 27 #define BERLIN2_SM_CTRL_SM_SOC_INT BIT(1) 28 #define BERLIN2_SM_CTRL_SOC_SM_INT BIT(2) 29 #define BERLIN2_SM_CTRL_ADC_SEL(x) ((x) << 5) /* 0-15 */ 30 #define BERLIN2_SM_CTRL_ADC_SEL_MASK GENMASK(8, 5) 31 #define BERLIN2_SM_CTRL_ADC_POWER BIT(9) 32 #define BERLIN2_SM_CTRL_ADC_CLKSEL_DIV2 (0x0 << 10) 33 #define BERLIN2_SM_CTRL_ADC_CLKSEL_DIV3 (0x1 << 10) 34 #define BERLIN2_SM_CTRL_ADC_CLKSEL_DIV4 (0x2 << 10) 35 #define BERLIN2_SM_CTRL_ADC_CLKSEL_DIV8 (0x3 << 10) 36 #define BERLIN2_SM_CTRL_ADC_CLKSEL_MASK GENMASK(11, 10) 37 #define BERLIN2_SM_CTRL_ADC_START BIT(12) 38 #define BERLIN2_SM_CTRL_ADC_RESET BIT(13) 39 #define BERLIN2_SM_CTRL_ADC_BANDGAP_RDY BIT(14) 40 #define BERLIN2_SM_CTRL_ADC_CONT_SINGLE (0x0 << 15) 41 #define BERLIN2_SM_CTRL_ADC_CONT_CONTINUOUS (0x1 << 15) 42 #define BERLIN2_SM_CTRL_ADC_BUFFER_EN BIT(16) 43 #define BERLIN2_SM_CTRL_ADC_VREF_EXT (0x0 << 17) 44 #define BERLIN2_SM_CTRL_ADC_VREF_INT (0x1 << 17) 45 #define BERLIN2_SM_CTRL_ADC_ROTATE BIT(19) 46 #define BERLIN2_SM_CTRL_TSEN_EN BIT(20) 47 #define BERLIN2_SM_CTRL_TSEN_CLK_SEL_125 (0x0 << 21) /* 1.25 MHz */ 48 #define BERLIN2_SM_CTRL_TSEN_CLK_SEL_250 (0x1 << 21) /* 2.5 MHz */ 49 #define BERLIN2_SM_CTRL_TSEN_MODE_0_125 (0x0 << 22) /* 0-125 C */ 50 #define BERLIN2_SM_CTRL_TSEN_MODE_10_50 (0x1 << 22) /* 10-50 C */ 51 #define BERLIN2_SM_CTRL_TSEN_RESET BIT(29) 52 #define BERLIN2_SM_ADC_DATA 0x20 53 #define BERLIN2_SM_ADC_MASK GENMASK(9, 0) 54 #define BERLIN2_SM_ADC_STATUS 0x1c 55 #define BERLIN2_SM_ADC_STATUS_DATA_RDY(x) BIT(x) /* 0-15 */ 56 #define BERLIN2_SM_ADC_STATUS_DATA_RDY_MASK GENMASK(15, 0) 57 #define BERLIN2_SM_ADC_STATUS_INT_EN(x) (BIT(x) << 16) /* 0-15 */ 58 #define BERLIN2_SM_ADC_STATUS_INT_EN_MASK GENMASK(31, 16) 59 #define BERLIN2_SM_TSEN_STATUS 0x24 60 #define BERLIN2_SM_TSEN_STATUS_DATA_RDY BIT(0) 61 #define BERLIN2_SM_TSEN_STATUS_INT_EN BIT(1) 62 #define BERLIN2_SM_TSEN_DATA 0x28 63 #define BERLIN2_SM_TSEN_MASK GENMASK(9, 0) 64 #define BERLIN2_SM_TSEN_CTRL 0x74 65 #define BERLIN2_SM_TSEN_CTRL_START BIT(8) 66 #define BERLIN2_SM_TSEN_CTRL_SETTLING_4 (0x0 << 21) /* 4 us */ 67 #define BERLIN2_SM_TSEN_CTRL_SETTLING_12 (0x1 << 21) /* 12 us */ 68 #define BERLIN2_SM_TSEN_CTRL_SETTLING_MASK BIT(21) 69 #define BERLIN2_SM_TSEN_CTRL_TRIM(x) ((x) << 22) 70 #define BERLIN2_SM_TSEN_CTRL_TRIM_MASK GENMASK(25, 22) 71 72 struct berlin2_adc_priv { 73 struct regmap *regmap; 74 struct mutex lock; 75 wait_queue_head_t wq; 76 bool data_available; 77 int data; 78 }; 79 80 #define BERLIN2_ADC_CHANNEL(n, t) \ 81 { \ 82 .channel = n, \ 83 .datasheet_name = "channel"#n, \ 84 .type = t, \ 85 .indexed = 1, \ 86 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \ 87 } 88 89 static const struct iio_chan_spec berlin2_adc_channels[] = { 90 BERLIN2_ADC_CHANNEL(0, IIO_VOLTAGE), /* external input */ 91 BERLIN2_ADC_CHANNEL(1, IIO_VOLTAGE), /* external input */ 92 BERLIN2_ADC_CHANNEL(2, IIO_VOLTAGE), /* external input */ 93 BERLIN2_ADC_CHANNEL(3, IIO_VOLTAGE), /* external input */ 94 BERLIN2_ADC_CHANNEL(4, IIO_VOLTAGE), /* reserved */ 95 BERLIN2_ADC_CHANNEL(5, IIO_VOLTAGE), /* reserved */ 96 { /* temperature sensor */ 97 .channel = 6, 98 .datasheet_name = "channel6", 99 .type = IIO_TEMP, 100 .indexed = 0, 101 .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED), 102 }, 103 BERLIN2_ADC_CHANNEL(7, IIO_VOLTAGE), /* reserved */ 104 IIO_CHAN_SOFT_TIMESTAMP(8), /* timestamp */ 105 }; 106 107 static int berlin2_adc_read(struct iio_dev *indio_dev, int channel) 108 { 109 struct berlin2_adc_priv *priv = iio_priv(indio_dev); 110 int data, ret; 111 112 mutex_lock(&priv->lock); 113 114 /* Enable the interrupts */ 115 regmap_write(priv->regmap, BERLIN2_SM_ADC_STATUS, 116 BERLIN2_SM_ADC_STATUS_INT_EN(channel)); 117 118 /* Configure the ADC */ 119 regmap_update_bits(priv->regmap, BERLIN2_SM_CTRL, 120 BERLIN2_SM_CTRL_ADC_RESET | 121 BERLIN2_SM_CTRL_ADC_SEL_MASK | 122 BERLIN2_SM_CTRL_ADC_START, 123 BERLIN2_SM_CTRL_ADC_SEL(channel) | 124 BERLIN2_SM_CTRL_ADC_START); 125 126 ret = wait_event_interruptible_timeout(priv->wq, priv->data_available, 127 msecs_to_jiffies(1000)); 128 129 /* Disable the interrupts */ 130 regmap_update_bits(priv->regmap, BERLIN2_SM_ADC_STATUS, 131 BERLIN2_SM_ADC_STATUS_INT_EN(channel), 0); 132 133 if (ret == 0) 134 ret = -ETIMEDOUT; 135 if (ret < 0) { 136 mutex_unlock(&priv->lock); 137 return ret; 138 } 139 140 regmap_update_bits(priv->regmap, BERLIN2_SM_CTRL, 141 BERLIN2_SM_CTRL_ADC_START, 0); 142 143 data = priv->data; 144 priv->data_available = false; 145 146 mutex_unlock(&priv->lock); 147 148 return data; 149 } 150 151 static int berlin2_adc_tsen_read(struct iio_dev *indio_dev) 152 { 153 struct berlin2_adc_priv *priv = iio_priv(indio_dev); 154 int data, ret; 155 156 mutex_lock(&priv->lock); 157 158 /* Enable interrupts */ 159 regmap_write(priv->regmap, BERLIN2_SM_TSEN_STATUS, 160 BERLIN2_SM_TSEN_STATUS_INT_EN); 161 162 /* Configure the ADC */ 163 regmap_update_bits(priv->regmap, BERLIN2_SM_CTRL, 164 BERLIN2_SM_CTRL_TSEN_RESET | 165 BERLIN2_SM_CTRL_ADC_ROTATE, 166 BERLIN2_SM_CTRL_ADC_ROTATE); 167 168 /* Configure the temperature sensor */ 169 regmap_update_bits(priv->regmap, BERLIN2_SM_TSEN_CTRL, 170 BERLIN2_SM_TSEN_CTRL_TRIM_MASK | 171 BERLIN2_SM_TSEN_CTRL_SETTLING_MASK | 172 BERLIN2_SM_TSEN_CTRL_START, 173 BERLIN2_SM_TSEN_CTRL_TRIM(3) | 174 BERLIN2_SM_TSEN_CTRL_SETTLING_12 | 175 BERLIN2_SM_TSEN_CTRL_START); 176 177 ret = wait_event_interruptible_timeout(priv->wq, priv->data_available, 178 msecs_to_jiffies(1000)); 179 180 /* Disable interrupts */ 181 regmap_update_bits(priv->regmap, BERLIN2_SM_TSEN_STATUS, 182 BERLIN2_SM_TSEN_STATUS_INT_EN, 0); 183 184 if (ret == 0) 185 ret = -ETIMEDOUT; 186 if (ret < 0) { 187 mutex_unlock(&priv->lock); 188 return ret; 189 } 190 191 regmap_update_bits(priv->regmap, BERLIN2_SM_TSEN_CTRL, 192 BERLIN2_SM_TSEN_CTRL_START, 0); 193 194 data = priv->data; 195 priv->data_available = false; 196 197 mutex_unlock(&priv->lock); 198 199 return data; 200 } 201 202 static int berlin2_adc_read_raw(struct iio_dev *indio_dev, 203 struct iio_chan_spec const *chan, int *val, 204 int *val2, long mask) 205 { 206 int temp; 207 208 switch (mask) { 209 case IIO_CHAN_INFO_RAW: 210 if (chan->type != IIO_VOLTAGE) 211 return -EINVAL; 212 213 *val = berlin2_adc_read(indio_dev, chan->channel); 214 if (*val < 0) 215 return *val; 216 217 return IIO_VAL_INT; 218 case IIO_CHAN_INFO_PROCESSED: 219 if (chan->type != IIO_TEMP) 220 return -EINVAL; 221 222 temp = berlin2_adc_tsen_read(indio_dev); 223 if (temp < 0) 224 return temp; 225 226 if (temp > 2047) 227 temp -= 4096; 228 229 /* Convert to milli Celsius */ 230 *val = ((temp * 100000) / 264 - 270000); 231 return IIO_VAL_INT; 232 default: 233 break; 234 } 235 236 return -EINVAL; 237 } 238 239 static irqreturn_t berlin2_adc_irq(int irq, void *private) 240 { 241 struct berlin2_adc_priv *priv = iio_priv(private); 242 unsigned val; 243 244 regmap_read(priv->regmap, BERLIN2_SM_ADC_STATUS, &val); 245 if (val & BERLIN2_SM_ADC_STATUS_DATA_RDY_MASK) { 246 regmap_read(priv->regmap, BERLIN2_SM_ADC_DATA, &priv->data); 247 priv->data &= BERLIN2_SM_ADC_MASK; 248 249 val &= ~BERLIN2_SM_ADC_STATUS_DATA_RDY_MASK; 250 regmap_write(priv->regmap, BERLIN2_SM_ADC_STATUS, val); 251 252 priv->data_available = true; 253 wake_up_interruptible(&priv->wq); 254 } 255 256 return IRQ_HANDLED; 257 } 258 259 static irqreturn_t berlin2_adc_tsen_irq(int irq, void *private) 260 { 261 struct berlin2_adc_priv *priv = iio_priv(private); 262 unsigned val; 263 264 regmap_read(priv->regmap, BERLIN2_SM_TSEN_STATUS, &val); 265 if (val & BERLIN2_SM_TSEN_STATUS_DATA_RDY) { 266 regmap_read(priv->regmap, BERLIN2_SM_TSEN_DATA, &priv->data); 267 priv->data &= BERLIN2_SM_TSEN_MASK; 268 269 val &= ~BERLIN2_SM_TSEN_STATUS_DATA_RDY; 270 regmap_write(priv->regmap, BERLIN2_SM_TSEN_STATUS, val); 271 272 priv->data_available = true; 273 wake_up_interruptible(&priv->wq); 274 } 275 276 return IRQ_HANDLED; 277 } 278 279 static const struct iio_info berlin2_adc_info = { 280 .read_raw = berlin2_adc_read_raw, 281 }; 282 283 static void berlin2_adc_powerdown(void *regmap) 284 { 285 regmap_update_bits(regmap, BERLIN2_SM_CTRL, 286 BERLIN2_SM_CTRL_ADC_POWER, 0); 287 288 } 289 290 static int berlin2_adc_probe(struct platform_device *pdev) 291 { 292 struct iio_dev *indio_dev; 293 struct berlin2_adc_priv *priv; 294 struct device_node *parent_np = of_get_parent(pdev->dev.of_node); 295 int irq, tsen_irq; 296 int ret; 297 298 indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*priv)); 299 if (!indio_dev) 300 return -ENOMEM; 301 302 priv = iio_priv(indio_dev); 303 304 priv->regmap = syscon_node_to_regmap(parent_np); 305 of_node_put(parent_np); 306 if (IS_ERR(priv->regmap)) 307 return PTR_ERR(priv->regmap); 308 309 irq = platform_get_irq_byname(pdev, "adc"); 310 if (irq < 0) 311 return irq; 312 313 tsen_irq = platform_get_irq_byname(pdev, "tsen"); 314 if (tsen_irq < 0) 315 return tsen_irq; 316 317 ret = devm_request_irq(&pdev->dev, irq, berlin2_adc_irq, 0, 318 pdev->dev.driver->name, indio_dev); 319 if (ret) 320 return ret; 321 322 ret = devm_request_irq(&pdev->dev, tsen_irq, berlin2_adc_tsen_irq, 323 0, pdev->dev.driver->name, indio_dev); 324 if (ret) 325 return ret; 326 327 init_waitqueue_head(&priv->wq); 328 mutex_init(&priv->lock); 329 330 indio_dev->name = dev_name(&pdev->dev); 331 indio_dev->modes = INDIO_DIRECT_MODE; 332 indio_dev->info = &berlin2_adc_info; 333 334 indio_dev->channels = berlin2_adc_channels; 335 indio_dev->num_channels = ARRAY_SIZE(berlin2_adc_channels); 336 337 /* Power up the ADC */ 338 regmap_update_bits(priv->regmap, BERLIN2_SM_CTRL, 339 BERLIN2_SM_CTRL_ADC_POWER, 340 BERLIN2_SM_CTRL_ADC_POWER); 341 342 ret = devm_add_action_or_reset(&pdev->dev, berlin2_adc_powerdown, 343 priv->regmap); 344 if (ret) 345 return ret; 346 347 return devm_iio_device_register(&pdev->dev, indio_dev); 348 } 349 350 static const struct of_device_id berlin2_adc_match[] = { 351 { .compatible = "marvell,berlin2-adc", }, 352 { }, 353 }; 354 MODULE_DEVICE_TABLE(of, berlin2_adc_match); 355 356 static struct platform_driver berlin2_adc_driver = { 357 .driver = { 358 .name = "berlin2-adc", 359 .of_match_table = berlin2_adc_match, 360 }, 361 .probe = berlin2_adc_probe, 362 }; 363 module_platform_driver(berlin2_adc_driver); 364 365 MODULE_AUTHOR("Antoine Tenart <antoine.tenart@free-electrons.com>"); 366 MODULE_DESCRIPTION("Marvell Berlin2 ADC driver"); 367 MODULE_LICENSE("GPL v2"); 368