drivers/misc/tps6594-esm.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * ESM (Error Signal Monitor) driver for TI TPS6594/TPS6593/LP8764 PMICs
   4  *
   5  * Copyright (C) 2023 BayLibre Incorporated - https://www.baylibre.com/
   6  */
   7
   8 #include <linux/interrupt.h>
   9 #include <linux/module.h>
  10 #include <linux/platform_device.h>
  11 #include <linux/pm_runtime.h>
  12 #include <linux/regmap.h>
  13
  14 #include <linux/mfd/tps6594.h>
  15
  16 #define TPS6594_DEV_REV_1 0x08
  17
  18 static irqreturn_t tps6594_esm_isr(int irq, void *dev_id)
  19 {
  20         struct platform_device *pdev = dev_id;
  21         int i;
  22
  23         for (i = 0 ; i < pdev->num_resources ; i++) {
  24                 if (irq == platform_get_irq_byname(pdev, pdev->resource[i].name)) {
  25                         dev_err(pdev->dev.parent, "%s error detected\n", pdev->resource[i].name);
  26                         return IRQ_HANDLED;
  27                 }
  28         }
  29
  30         return IRQ_NONE;
  31 }
  32
  33 static int tps6594_esm_probe(struct platform_device *pdev)
  34 {
  35         struct tps6594 *tps = dev_get_drvdata(pdev->dev.parent);
  36         struct device *dev = &pdev->dev;
  37         unsigned int rev;
  38         int irq;
  39         int ret;
  40         int i;
  41
  42         /*
  43          * Due to a bug in revision 1 of the PMIC, the GPIO3 used for the
  44          * SoC ESM function is used to power the load switch instead.
  45          * As a consequence, ESM can not be used on those PMIC.
  46          * Check the version and return an error in case of revision 1.
  47          */
  48         ret = regmap_read(tps->regmap, TPS6594_REG_DEV_REV, &rev);
  49         if (ret)
  50                 return dev_err_probe(dev, ret,
  51                                      "Failed to read PMIC revision\n");
  52         if (rev == TPS6594_DEV_REV_1)
  53                 return dev_err_probe(dev, -ENODEV,
  54                               "ESM not supported for revision 1 PMIC\n");
  55
  56         for (i = 0; i < pdev->num_resources; i++) {
  57                 irq = platform_get_irq_byname(pdev, pdev->resource[i].name);
  58                 if (irq < 0)
  59                         return dev_err_probe(dev, irq, "Failed to get %s irq\n",
  60                                              pdev->resource[i].name);
  61
  62                 ret = devm_request_threaded_irq(dev, irq, NULL,
  63                                                 tps6594_esm_isr, IRQF_ONESHOT,
  64                                                 pdev->resource[i].name, pdev);
  65                 if (ret)
  66                         return dev_err_probe(dev, ret, "Failed to request irq\n");
  67         }
  68
  69         ret = regmap_set_bits(tps->regmap, TPS6594_REG_ESM_SOC_MODE_CFG,
  70                               TPS6594_BIT_ESM_SOC_EN | TPS6594_BIT_ESM_SOC_ENDRV);
  71         if (ret)
  72                 return dev_err_probe(dev, ret, "Failed to configure ESM\n");
  73
  74         ret = regmap_set_bits(tps->regmap, TPS6594_REG_ESM_SOC_START_REG,
  75                               TPS6594_BIT_ESM_SOC_START);
  76         if (ret)
  77                 return dev_err_probe(dev, ret, "Failed to start ESM\n");
  78
  79         pm_runtime_enable(dev);
  80         pm_runtime_get_sync(dev);
  81
  82         return 0;
  83 }
  84
  85 static int tps6594_esm_remove(struct platform_device *pdev)
  86 {
  87         struct tps6594 *tps = dev_get_drvdata(pdev->dev.parent);
  88         struct device *dev = &pdev->dev;
  89         int ret;
  90
  91         ret = regmap_clear_bits(tps->regmap, TPS6594_REG_ESM_SOC_START_REG,
  92                                 TPS6594_BIT_ESM_SOC_START);
  93         if (ret) {
  94                 dev_err(dev, "Failed to stop ESM\n");
  95                 goto out;
  96         }
  97
  98         ret = regmap_clear_bits(tps->regmap, TPS6594_REG_ESM_SOC_MODE_CFG,
  99                                 TPS6594_BIT_ESM_SOC_EN | TPS6594_BIT_ESM_SOC_ENDRV);
 100         if (ret)
 101                 dev_err(dev, "Failed to unconfigure ESM\n");
 102
 103 out:
 104         pm_runtime_put_sync(dev);
 105         pm_runtime_disable(dev);
 106
 107         return ret;
 108 }
 109
 110 static int tps6594_esm_suspend(struct device *dev)
 111 {
 112         struct tps6594 *tps = dev_get_drvdata(dev->parent);
 113         int ret;
 114
 115         ret = regmap_clear_bits(tps->regmap, TPS6594_REG_ESM_SOC_START_REG,
 116                                 TPS6594_BIT_ESM_SOC_START);
 117
 118         pm_runtime_put_sync(dev);
 119
 120         return ret;
 121 }
 122
 123 static int tps6594_esm_resume(struct device *dev)
 124 {
 125         struct tps6594 *tps = dev_get_drvdata(dev->parent);
 126
 127         pm_runtime_get_sync(dev);
 128
 129         return regmap_set_bits(tps->regmap, TPS6594_REG_ESM_SOC_START_REG,
 130                                TPS6594_BIT_ESM_SOC_START);
 131 }
 132
 133 static DEFINE_SIMPLE_DEV_PM_OPS(tps6594_esm_pm_ops, tps6594_esm_suspend, tps6594_esm_resume);
 134
 135 static struct platform_driver tps6594_esm_driver = {
 136         .driver = {
 137                 .name = "tps6594-esm",
 138                 .pm = pm_sleep_ptr(&tps6594_esm_pm_ops),
 139         },
 140         .probe = tps6594_esm_probe,
 141         .remove = tps6594_esm_remove,
 142 };
 143
 144 module_platform_driver(tps6594_esm_driver);
 145
 146 MODULE_ALIAS("platform:tps6594-esm");
 147 MODULE_AUTHOR("Julien Panis <jpanis@baylibre.com>");
 148 MODULE_DESCRIPTION("TPS6594 Error Signal Monitor Driver");
 149 MODULE_LICENSE("GPL");