drivers/misc/tps6594-pfsm.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * PFSM (Pre-configurable Finite State Machine) driver for TI TPS65224/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  * @chip_id: chip identifier of the device
  43  */
  44 struct tps6594_pfsm {
  45         struct miscdevice miscdev;
  46         struct regmap *regmap;
  47         unsigned long chip_id;
  48 };
  49
  50 static ssize_t tps6594_pfsm_read(struct file *f, char __user *buf,
  51                                  size_t count, loff_t *ppos)
  52 {
  53         struct tps6594_pfsm *pfsm = TPS6594_FILE_TO_PFSM(f);
  54         loff_t pos = *ppos;
  55         unsigned int val;
  56         int ret;
  57         int i;
  58
  59         if (pos < 0)
  60                 return -EINVAL;
  61         if (pos >= TPS6594_PMIC_MAX_POS)
  62                 return 0;
  63         if (count > TPS6594_PMIC_MAX_POS - pos)
  64                 count = TPS6594_PMIC_MAX_POS - pos;
  65
  66         for (i = 0 ; i < count ; i++) {
  67                 ret = regmap_read(pfsm->regmap, pos + i, &val);
  68                 if (ret)
  69                         return ret;
  70
  71                 if (put_user(val, buf + i))
  72                         return -EFAULT;
  73         }
  74
  75         *ppos = pos + count;
  76
  77         return count;
  78 }
  79
  80 static ssize_t tps6594_pfsm_write(struct file *f, const char __user *buf,
  81                                   size_t count, loff_t *ppos)
  82 {
  83         struct tps6594_pfsm *pfsm = TPS6594_FILE_TO_PFSM(f);
  84         loff_t pos = *ppos;
  85         char val;
  86         int ret;
  87         int i;
  88
  89         if (pos < 0)
  90                 return -EINVAL;
  91         if (pos >= TPS6594_PMIC_MAX_POS || !count)
  92                 return 0;
  93         if (count > TPS6594_PMIC_MAX_POS - pos)
  94                 count = TPS6594_PMIC_MAX_POS - pos;
  95
  96         for (i = 0 ; i < count ; i++) {
  97                 if (get_user(val, buf + i))
  98                         return -EFAULT;
  99
 100                 ret = regmap_write(pfsm->regmap, pos + i, val);
 101                 if (ret)
 102                         return ret;
 103         }
 104
 105         *ppos = pos + count;
 106
 107         return count;
 108 }
 109
 110 static int tps6594_pfsm_configure_ret_trig(struct regmap *regmap, u8 gpio_ret, u8 ddr_ret)
 111 {
 112         int ret;
 113
 114         if (gpio_ret)
 115                 ret = regmap_set_bits(regmap, TPS6594_REG_FSM_I2C_TRIGGERS,
 116                                       TPS6594_BIT_TRIGGER_I2C(5) | TPS6594_BIT_TRIGGER_I2C(6));
 117         else
 118                 ret = regmap_clear_bits(regmap, TPS6594_REG_FSM_I2C_TRIGGERS,
 119                                         TPS6594_BIT_TRIGGER_I2C(5) | TPS6594_BIT_TRIGGER_I2C(6));
 120         if (ret)
 121                 return ret;
 122
 123         if (ddr_ret)
 124                 ret = regmap_set_bits(regmap, TPS6594_REG_FSM_I2C_TRIGGERS,
 125                                       TPS6594_BIT_TRIGGER_I2C(7));
 126         else
 127                 ret = regmap_clear_bits(regmap, TPS6594_REG_FSM_I2C_TRIGGERS,
 128                                         TPS6594_BIT_TRIGGER_I2C(7));
 129
 130         return ret;
 131 }
 132
 133 static long tps6594_pfsm_ioctl(struct file *f, unsigned int cmd, unsigned long arg)
 134 {
 135         struct tps6594_pfsm *pfsm = TPS6594_FILE_TO_PFSM(f);
 136         struct pmic_state_opt state_opt;
 137         void __user *argp = (void __user *)arg;
 138         unsigned int regmap_reg, mask;
 139         int ret = -ENOIOCTLCMD;
 140
 141         switch (cmd) {
 142         case PMIC_GOTO_STANDBY:
 143                 /* Disable LP mode on TPS6594 Family PMIC */
 144                 if (pfsm->chip_id != TPS65224) {
 145                         ret = regmap_clear_bits(pfsm->regmap, TPS6594_REG_RTC_CTRL_2,
 146                                                 TPS6594_BIT_LP_STANDBY_SEL);
 147
 148                         if (ret)
 149                                 return ret;
 150                 }
 151
 152                 /* Force trigger */
 153                 ret = regmap_write_bits(pfsm->regmap, TPS6594_REG_FSM_I2C_TRIGGERS,
 154                                         TPS6594_BIT_TRIGGER_I2C(0), TPS6594_BIT_TRIGGER_I2C(0));
 155                 break;
 156         case PMIC_GOTO_LP_STANDBY:
 157                 /* TPS65224 does not support LP STANDBY */
 158                 if (pfsm->chip_id == TPS65224)
 159                         return ret;
 160
 161                 /* Enable LP mode */
 162                 ret = regmap_set_bits(pfsm->regmap, TPS6594_REG_RTC_CTRL_2,
 163                                       TPS6594_BIT_LP_STANDBY_SEL);
 164                 if (ret)
 165                         return ret;
 166
 167                 /* Force trigger */
 168                 ret = regmap_write_bits(pfsm->regmap, TPS6594_REG_FSM_I2C_TRIGGERS,
 169                                         TPS6594_BIT_TRIGGER_I2C(0), TPS6594_BIT_TRIGGER_I2C(0));
 170                 break;
 171         case PMIC_UPDATE_PGM:
 172                 /* Force trigger */
 173                 ret = regmap_write_bits(pfsm->regmap, TPS6594_REG_FSM_I2C_TRIGGERS,
 174                                         TPS6594_BIT_TRIGGER_I2C(3), TPS6594_BIT_TRIGGER_I2C(3));
 175                 break;
 176         case PMIC_SET_ACTIVE_STATE:
 177                 /* Modify NSLEEP1-2 bits */
 178                 ret = regmap_set_bits(pfsm->regmap, TPS6594_REG_FSM_NSLEEP_TRIGGERS,
 179                                       TPS6594_BIT_NSLEEP1B | TPS6594_BIT_NSLEEP2B);
 180                 break;
 181         case PMIC_SET_MCU_ONLY_STATE:
 182                 /* TPS65224 does not support MCU_ONLY_STATE */
 183                 if (pfsm->chip_id == TPS65224)
 184                         return ret;
 185
 186                 if (copy_from_user(&state_opt, argp, sizeof(state_opt)))
 187                         return -EFAULT;
 188
 189                 /* Configure retention triggers */
 190                 ret = tps6594_pfsm_configure_ret_trig(pfsm->regmap, state_opt.gpio_retention,
 191                                                       state_opt.ddr_retention);
 192                 if (ret)
 193                         return ret;
 194
 195                 /* Modify NSLEEP1-2 bits */
 196                 ret = regmap_clear_bits(pfsm->regmap, TPS6594_REG_FSM_NSLEEP_TRIGGERS,
 197                                         TPS6594_BIT_NSLEEP1B);
 198                 if (ret)
 199                         return ret;
 200
 201                 ret = regmap_set_bits(pfsm->regmap, TPS6594_REG_FSM_NSLEEP_TRIGGERS,
 202                                       TPS6594_BIT_NSLEEP2B);
 203                 break;
 204         case PMIC_SET_RETENTION_STATE:
 205                 if (copy_from_user(&state_opt, argp, sizeof(state_opt)))
 206                         return -EFAULT;
 207
 208                 /* Configure wake-up destination */
 209                 if (pfsm->chip_id == TPS65224) {
 210                         regmap_reg = TPS65224_REG_STARTUP_CTRL;
 211                         mask = TPS65224_MASK_STARTUP_DEST;
 212                 } else {
 213                         regmap_reg = TPS6594_REG_RTC_CTRL_2;
 214                         mask = TPS6594_MASK_STARTUP_DEST;
 215                 }
 216
 217                 if (state_opt.mcu_only_startup_dest)
 218                         ret = regmap_write_bits(pfsm->regmap, regmap_reg,
 219                                                 mask, TPS6594_STARTUP_DEST_MCU_ONLY);
 220                 else
 221                         ret = regmap_write_bits(pfsm->regmap, regmap_reg,
 222                                                 mask, TPS6594_STARTUP_DEST_ACTIVE);
 223                 if (ret)
 224                         return ret;
 225
 226                 /* Configure retention triggers */
 227                 ret = tps6594_pfsm_configure_ret_trig(pfsm->regmap, state_opt.gpio_retention,
 228                                                       state_opt.ddr_retention);
 229                 if (ret)
 230                         return ret;
 231
 232                 /* Modify NSLEEP1-2 bits */
 233                 ret = regmap_clear_bits(pfsm->regmap, TPS6594_REG_FSM_NSLEEP_TRIGGERS,
 234                                         pfsm->chip_id == TPS65224 ?
 235                                         TPS6594_BIT_NSLEEP1B : TPS6594_BIT_NSLEEP2B);
 236                 break;
 237         }
 238
 239         return ret;
 240 }
 241
 242 static const struct file_operations tps6594_pfsm_fops = {
 243         .owner          = THIS_MODULE,
 244         .llseek         = generic_file_llseek,
 245         .read           = tps6594_pfsm_read,
 246         .write          = tps6594_pfsm_write,
 247         .unlocked_ioctl = tps6594_pfsm_ioctl,
 248         .compat_ioctl   = compat_ptr_ioctl,
 249 };
 250
 251 static irqreturn_t tps6594_pfsm_isr(int irq, void *dev_id)
 252 {
 253         struct platform_device *pdev = dev_id;
 254         int i;
 255
 256         for (i = 0 ; i < pdev->num_resources ; i++) {
 257                 if (irq == platform_get_irq_byname(pdev, pdev->resource[i].name)) {
 258                         dev_err(pdev->dev.parent, "%s event detected\n", pdev->resource[i].name);
 259                         return IRQ_HANDLED;
 260                 }
 261         }
 262
 263         return IRQ_NONE;
 264 }
 265
 266 static int tps6594_pfsm_probe(struct platform_device *pdev)
 267 {
 268         struct tps6594_pfsm *pfsm;
 269         struct tps6594 *tps = dev_get_drvdata(pdev->dev.parent);
 270         struct device *dev = &pdev->dev;
 271         int irq;
 272         int ret;
 273         int i;
 274
 275         pfsm = devm_kzalloc(dev, sizeof(struct tps6594_pfsm), GFP_KERNEL);
 276         if (!pfsm)
 277                 return -ENOMEM;
 278
 279         pfsm->regmap = tps->regmap;
 280
 281         pfsm->miscdev.minor = MISC_DYNAMIC_MINOR;
 282         pfsm->miscdev.name = devm_kasprintf(dev, GFP_KERNEL, "pfsm-%ld-0x%02x",
 283                                             tps->chip_id, tps->reg);
 284         pfsm->miscdev.fops = &tps6594_pfsm_fops;
 285         pfsm->miscdev.parent = dev->parent;
 286         pfsm->chip_id = tps->chip_id;
 287
 288         for (i = 0 ; i < pdev->num_resources ; i++) {
 289                 irq = platform_get_irq_byname(pdev, pdev->resource[i].name);
 290                 if (irq < 0)
 291                         return irq;
 292
 293                 ret = devm_request_threaded_irq(dev, irq, NULL,
 294                                                 tps6594_pfsm_isr, IRQF_ONESHOT,
 295                                                 pdev->resource[i].name, pdev);
 296                 if (ret)
 297                         return dev_err_probe(dev, ret, "Failed to request irq\n");
 298         }
 299
 300         platform_set_drvdata(pdev, pfsm);
 301
 302         return misc_register(&pfsm->miscdev);
 303 }
 304
 305 static void tps6594_pfsm_remove(struct platform_device *pdev)
 306 {
 307         struct tps6594_pfsm *pfsm = platform_get_drvdata(pdev);
 308
 309         misc_deregister(&pfsm->miscdev);
 310 }
 311
 312 static struct platform_driver tps6594_pfsm_driver = {
 313         .driver = {
 314                 .name = "tps6594-pfsm",
 315         },
 316         .probe = tps6594_pfsm_probe,
 317         .remove = tps6594_pfsm_remove,
 318 };
 319
 320 module_platform_driver(tps6594_pfsm_driver);
 321
 322 MODULE_ALIAS("platform:tps6594-pfsm");
 323 MODULE_AUTHOR("Julien Panis <[email protected]>");
 324 MODULE_DESCRIPTION("TPS6594 Pre-configurable Finite State Machine Driver");
 325 MODULE_LICENSE("GPL");