drivers/misc/tps6594-pfsm.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * PFSM (Pre-configurable Finite State Machine) driver for TI TPS6594/TPS6593/LP8764 PMICs
   4  *
   5  * Copyright (C) 2023 BayLibre Incorporated - https://www.baylibre.com/
   6  */
   7
   8 #include <linux/errno.h>
   9 #include <linux/fs.h>
  10 #include <linux/interrupt.h>
  11 #include <linux/ioctl.h>
  12 #include <linux/miscdevice.h>
  13 #include <linux/module.h>
  14 #include <linux/platform_device.h>
  15 #include <linux/regmap.h>
  16
  17 #include <linux/mfd/tps6594.h>
  18
  19 #include <linux/tps6594_pfsm.h>
  20
  21 #define TPS6594_STARTUP_DEST_MCU_ONLY_VAL 2
  22 #define TPS6594_STARTUP_DEST_ACTIVE_VAL   3
  23 #define TPS6594_STARTUP_DEST_SHIFT        5
  24 #define TPS6594_STARTUP_DEST_MCU_ONLY     (TPS6594_STARTUP_DEST_MCU_ONLY_VAL \
  25                                            << TPS6594_STARTUP_DEST_SHIFT)
  26 #define TPS6594_STARTUP_DEST_ACTIVE       (TPS6594_STARTUP_DEST_ACTIVE_VAL \
  27                                            << TPS6594_STARTUP_DEST_SHIFT)
  28
  29 /*
  30  * To update the PMIC firmware, the user must be able to access
  31  * page 0 (user registers) and page 1 (NVM control and configuration).
  32  */
  33 #define TPS6594_PMIC_MAX_POS 0x200
  34
  35 #define TPS6594_FILE_TO_PFSM(f) container_of((f)->private_data, struct tps6594_pfsm, miscdev)
  36
  37 /**
  38  * struct tps6594_pfsm - device private data structure
  39  *
  40  * @miscdev: misc device infos
  41  * @regmap:  regmap for accessing the device registers
  42  */
  43 struct tps6594_pfsm {
  44         struct miscdevice miscdev;
  45         struct regmap *regmap;
  46 };
  47
  48 static ssize_t tps6594_pfsm_read(struct file *f, char __user *buf,
  49                                  size_t count, loff_t *ppos)
  50 {
  51         struct tps6594_pfsm *pfsm = TPS6594_FILE_TO_PFSM(f);
  52         loff_t pos = *ppos;
  53         unsigned int val;
  54         int ret;
  55         int i;
  56
  57         if (pos < 0)
  58                 return -EINVAL;
  59         if (pos >= TPS6594_PMIC_MAX_POS)
  60                 return 0;
  61         if (count > TPS6594_PMIC_MAX_POS - pos)
  62                 count = TPS6594_PMIC_MAX_POS - pos;
  63
  64         for (i = 0 ; i < count ; i++) {
  65                 ret = regmap_read(pfsm->regmap, pos + i, &val);
  66                 if (ret)
  67                         return ret;
  68
  69                 if (put_user(val, buf + i))
  70                         return -EFAULT;
  71         }
  72
  73         *ppos = pos + count;
  74
  75         return count;
  76 }
  77
  78 static ssize_t tps6594_pfsm_write(struct file *f, const char __user *buf,
  79                                   size_t count, loff_t *ppos)
  80 {
  81         struct tps6594_pfsm *pfsm = TPS6594_FILE_TO_PFSM(f);
  82         loff_t pos = *ppos;
  83         char val;
  84         int ret;
  85         int i;
  86
  87         if (pos < 0)
  88                 return -EINVAL;
  89         if (pos >= TPS6594_PMIC_MAX_POS || !count)
  90                 return 0;
  91         if (count > TPS6594_PMIC_MAX_POS - pos)
  92                 count = TPS6594_PMIC_MAX_POS - pos;
  93
  94         for (i = 0 ; i < count ; i++) {
  95                 if (get_user(val, buf + i))
  96                         return -EFAULT;
  97
  98                 ret = regmap_write(pfsm->regmap, pos + i, val);
  99                 if (ret)
 100                         return ret;
 101         }
 102
 103         *ppos = pos + count;
 104
 105         return count;
 106 }
 107
 108 static int tps6594_pfsm_configure_ret_trig(struct regmap *regmap, u8 gpio_ret, u8 ddr_ret)
 109 {
 110         int ret;
 111
 112         if (gpio_ret)
 113                 ret = regmap_set_bits(regmap, TPS6594_REG_FSM_I2C_TRIGGERS,
 114                                       TPS6594_BIT_TRIGGER_I2C(5) | TPS6594_BIT_TRIGGER_I2C(6));
 115         else
 116                 ret = regmap_clear_bits(regmap, TPS6594_REG_FSM_I2C_TRIGGERS,
 117                                         TPS6594_BIT_TRIGGER_I2C(5) | TPS6594_BIT_TRIGGER_I2C(6));
 118         if (ret)
 119                 return ret;
 120
 121         if (ddr_ret)
 122                 ret = regmap_set_bits(regmap, TPS6594_REG_FSM_I2C_TRIGGERS,
 123                                       TPS6594_BIT_TRIGGER_I2C(7));
 124         else
 125                 ret = regmap_clear_bits(regmap, TPS6594_REG_FSM_I2C_TRIGGERS,
 126                                         TPS6594_BIT_TRIGGER_I2C(7));
 127
 128         return ret;
 129 }
 130
 131 static long tps6594_pfsm_ioctl(struct file *f, unsigned int cmd, unsigned long arg)
 132 {
 133         struct tps6594_pfsm *pfsm = TPS6594_FILE_TO_PFSM(f);
 134         struct pmic_state_opt state_opt;
 135         void __user *argp = (void __user *)arg;
 136         int ret = -ENOIOCTLCMD;
 137
 138         switch (cmd) {
 139         case PMIC_GOTO_STANDBY:
 140                 /* Disable LP mode */
 141                 ret = regmap_clear_bits(pfsm->regmap, TPS6594_REG_RTC_CTRL_2,
 142                                         TPS6594_BIT_LP_STANDBY_SEL);
 143                 if (ret)
 144                         return ret;
 145
 146                 /* Force trigger */
 147                 ret = regmap_write_bits(pfsm->regmap, TPS6594_REG_FSM_I2C_TRIGGERS,
 148                                         TPS6594_BIT_TRIGGER_I2C(0), TPS6594_BIT_TRIGGER_I2C(0));
 149                 break;
 150         case PMIC_GOTO_LP_STANDBY:
 151                 /* Enable LP mode */
 152                 ret = regmap_set_bits(pfsm->regmap, TPS6594_REG_RTC_CTRL_2,
 153                                       TPS6594_BIT_LP_STANDBY_SEL);
 154                 if (ret)
 155                         return ret;
 156
 157                 /* Force trigger */
 158                 ret = regmap_write_bits(pfsm->regmap, TPS6594_REG_FSM_I2C_TRIGGERS,
 159                                         TPS6594_BIT_TRIGGER_I2C(0), TPS6594_BIT_TRIGGER_I2C(0));
 160                 break;
 161         case PMIC_UPDATE_PGM:
 162                 /* Force trigger */
 163                 ret = regmap_write_bits(pfsm->regmap, TPS6594_REG_FSM_I2C_TRIGGERS,
 164                                         TPS6594_BIT_TRIGGER_I2C(3), TPS6594_BIT_TRIGGER_I2C(3));
 165                 break;
 166         case PMIC_SET_ACTIVE_STATE:
 167                 /* Modify NSLEEP1-2 bits */
 168                 ret = regmap_set_bits(pfsm->regmap, TPS6594_REG_FSM_NSLEEP_TRIGGERS,
 169                                       TPS6594_BIT_NSLEEP1B | TPS6594_BIT_NSLEEP2B);
 170                 break;
 171         case PMIC_SET_MCU_ONLY_STATE:
 172                 if (copy_from_user(&state_opt, argp, sizeof(state_opt)))
 173                         return -EFAULT;
 174
 175                 /* Configure retention triggers */
 176                 ret = tps6594_pfsm_configure_ret_trig(pfsm->regmap, state_opt.gpio_retention,
 177                                                       state_opt.ddr_retention);
 178                 if (ret)
 179                         return ret;
 180
 181                 /* Modify NSLEEP1-2 bits */
 182                 ret = regmap_clear_bits(pfsm->regmap, TPS6594_REG_FSM_NSLEEP_TRIGGERS,
 183                                         TPS6594_BIT_NSLEEP1B);
 184                 if (ret)
 185                         return ret;
 186
 187                 ret = regmap_set_bits(pfsm->regmap, TPS6594_REG_FSM_NSLEEP_TRIGGERS,
 188                                       TPS6594_BIT_NSLEEP2B);
 189                 break;
 190         case PMIC_SET_RETENTION_STATE:
 191                 if (copy_from_user(&state_opt, argp, sizeof(state_opt)))
 192                         return -EFAULT;
 193
 194                 /* Configure wake-up destination */
 195                 if (state_opt.mcu_only_startup_dest)
 196                         ret = regmap_write_bits(pfsm->regmap, TPS6594_REG_RTC_CTRL_2,
 197                                                 TPS6594_MASK_STARTUP_DEST,
 198                                                 TPS6594_STARTUP_DEST_MCU_ONLY);
 199                 else
 200                         ret = regmap_write_bits(pfsm->regmap, TPS6594_REG_RTC_CTRL_2,
 201                                                 TPS6594_MASK_STARTUP_DEST,
 202                                                 TPS6594_STARTUP_DEST_ACTIVE);
 203                 if (ret)
 204                         return ret;
 205
 206                 /* Configure retention triggers */
 207                 ret = tps6594_pfsm_configure_ret_trig(pfsm->regmap, state_opt.gpio_retention,
 208                                                       state_opt.ddr_retention);
 209                 if (ret)
 210                         return ret;
 211
 212                 /* Modify NSLEEP1-2 bits */
 213                 ret = regmap_clear_bits(pfsm->regmap, TPS6594_REG_FSM_NSLEEP_TRIGGERS,
 214                                         TPS6594_BIT_NSLEEP2B);
 215                 break;
 216         }
 217
 218         return ret;
 219 }
 220
 221 static const struct file_operations tps6594_pfsm_fops = {
 222         .owner          = THIS_MODULE,
 223         .llseek         = generic_file_llseek,
 224         .read           = tps6594_pfsm_read,
 225         .write          = tps6594_pfsm_write,
 226         .unlocked_ioctl = tps6594_pfsm_ioctl,
 227         .compat_ioctl   = compat_ptr_ioctl,
 228 };
 229
 230 static irqreturn_t tps6594_pfsm_isr(int irq, void *dev_id)
 231 {
 232         struct platform_device *pdev = dev_id;
 233         int i;
 234
 235         for (i = 0 ; i < pdev->num_resources ; i++) {
 236                 if (irq == platform_get_irq_byname(pdev, pdev->resource[i].name)) {
 237                         dev_err(pdev->dev.parent, "%s event detected\n", pdev->resource[i].name);
 238                         return IRQ_HANDLED;
 239                 }
 240         }
 241
 242         return IRQ_NONE;
 243 }
 244
 245 static int tps6594_pfsm_probe(struct platform_device *pdev)
 246 {
 247         struct tps6594_pfsm *pfsm;
 248         struct tps6594 *tps = dev_get_drvdata(pdev->dev.parent);
 249         struct device *dev = &pdev->dev;
 250         int irq;
 251         int ret;
 252         int i;
 253
 254         pfsm = devm_kzalloc(dev, sizeof(struct tps6594_pfsm), GFP_KERNEL);
 255         if (!pfsm)
 256                 return -ENOMEM;
 257
 258         pfsm->regmap = tps->regmap;
 259
 260         pfsm->miscdev.minor = MISC_DYNAMIC_MINOR;
 261         pfsm->miscdev.name = devm_kasprintf(dev, GFP_KERNEL, "pfsm-%ld-0x%02x",
 262                                             tps->chip_id, tps->reg);
 263         pfsm->miscdev.fops = &tps6594_pfsm_fops;
 264         pfsm->miscdev.parent = dev->parent;
 265
 266         for (i = 0 ; i < pdev->num_resources ; i++) {
 267                 irq = platform_get_irq_byname(pdev, pdev->resource[i].name);
 268                 if (irq < 0)
 269                         return irq;
 270
 271                 ret = devm_request_threaded_irq(dev, irq, NULL,
 272                                                 tps6594_pfsm_isr, IRQF_ONESHOT,
 273                                                 pdev->resource[i].name, pdev);
 274                 if (ret)
 275                         return dev_err_probe(dev, ret, "Failed to request irq\n");
 276         }
 277
 278         platform_set_drvdata(pdev, pfsm);
 279
 280         return misc_register(&pfsm->miscdev);
 281 }
 282
 283 static void tps6594_pfsm_remove(struct platform_device *pdev)
 284 {
 285         struct tps6594_pfsm *pfsm = platform_get_drvdata(pdev);
 286
 287         misc_deregister(&pfsm->miscdev);
 288 }
 289
 290 static struct platform_driver tps6594_pfsm_driver = {
 291         .driver = {
 292                 .name = "tps6594-pfsm",
 293         },
 294         .probe = tps6594_pfsm_probe,
 295         .remove_new = tps6594_pfsm_remove,
 296 };
 297
 298 module_platform_driver(tps6594_pfsm_driver);
 299
 300 MODULE_ALIAS("platform:tps6594-pfsm");
 301 MODULE_AUTHOR("Julien Panis <jpanis@baylibre.com>");
 302 MODULE_DESCRIPTION("TPS6594 Pre-configurable Finite State Machine Driver");
 303 MODULE_LICENSE("GPL");