xref: /openbmc/linux/drivers/misc/tps6594-esm.c (revision 1314e122)
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 
tps6594_esm_isr(int irq,void * dev_id)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 
tps6594_esm_probe(struct platform_device * pdev)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 irq;
60 
61 		ret = devm_request_threaded_irq(dev, irq, NULL,
62 						tps6594_esm_isr, IRQF_ONESHOT,
63 						pdev->resource[i].name, pdev);
64 		if (ret)
65 			return dev_err_probe(dev, ret, "Failed to request irq\n");
66 	}
67 
68 	ret = regmap_set_bits(tps->regmap, TPS6594_REG_ESM_SOC_MODE_CFG,
69 			      TPS6594_BIT_ESM_SOC_EN | TPS6594_BIT_ESM_SOC_ENDRV);
70 	if (ret)
71 		return dev_err_probe(dev, ret, "Failed to configure ESM\n");
72 
73 	ret = regmap_set_bits(tps->regmap, TPS6594_REG_ESM_SOC_START_REG,
74 			      TPS6594_BIT_ESM_SOC_START);
75 	if (ret)
76 		return dev_err_probe(dev, ret, "Failed to start ESM\n");
77 
78 	pm_runtime_enable(dev);
79 	pm_runtime_get_sync(dev);
80 
81 	return 0;
82 }
83 
tps6594_esm_remove(struct platform_device * pdev)84 static void tps6594_esm_remove(struct platform_device *pdev)
85 {
86 	struct tps6594 *tps = dev_get_drvdata(pdev->dev.parent);
87 	struct device *dev = &pdev->dev;
88 	int ret;
89 
90 	ret = regmap_clear_bits(tps->regmap, TPS6594_REG_ESM_SOC_START_REG,
91 				TPS6594_BIT_ESM_SOC_START);
92 	if (ret) {
93 		dev_err(dev, "Failed to stop ESM\n");
94 		goto out;
95 	}
96 
97 	ret = regmap_clear_bits(tps->regmap, TPS6594_REG_ESM_SOC_MODE_CFG,
98 				TPS6594_BIT_ESM_SOC_EN | TPS6594_BIT_ESM_SOC_ENDRV);
99 	if (ret)
100 		dev_err(dev, "Failed to unconfigure ESM\n");
101 
102 out:
103 	pm_runtime_put_sync(dev);
104 	pm_runtime_disable(dev);
105 }
106 
tps6594_esm_suspend(struct device * dev)107 static int tps6594_esm_suspend(struct device *dev)
108 {
109 	struct tps6594 *tps = dev_get_drvdata(dev->parent);
110 	int ret;
111 
112 	ret = regmap_clear_bits(tps->regmap, TPS6594_REG_ESM_SOC_START_REG,
113 				TPS6594_BIT_ESM_SOC_START);
114 
115 	pm_runtime_put_sync(dev);
116 
117 	return ret;
118 }
119 
tps6594_esm_resume(struct device * dev)120 static int tps6594_esm_resume(struct device *dev)
121 {
122 	struct tps6594 *tps = dev_get_drvdata(dev->parent);
123 
124 	pm_runtime_get_sync(dev);
125 
126 	return regmap_set_bits(tps->regmap, TPS6594_REG_ESM_SOC_START_REG,
127 			       TPS6594_BIT_ESM_SOC_START);
128 }
129 
130 static DEFINE_SIMPLE_DEV_PM_OPS(tps6594_esm_pm_ops, tps6594_esm_suspend, tps6594_esm_resume);
131 
132 static struct platform_driver tps6594_esm_driver = {
133 	.driver	= {
134 		.name = "tps6594-esm",
135 		.pm = pm_sleep_ptr(&tps6594_esm_pm_ops),
136 	},
137 	.probe = tps6594_esm_probe,
138 	.remove_new = tps6594_esm_remove,
139 };
140 
141 module_platform_driver(tps6594_esm_driver);
142 
143 MODULE_ALIAS("platform:tps6594-esm");
144 MODULE_AUTHOR("Julien Panis <jpanis@baylibre.com>");
145 MODULE_DESCRIPTION("TPS6594 Error Signal Monitor Driver");
146 MODULE_LICENSE("GPL");
147