xref: /openbmc/linux/drivers/misc/tps6594-esm.c (revision cd99b9eb)
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");
150