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
18static 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
33static 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
84static 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
102out:
103	pm_runtime_put_sync(dev);
104	pm_runtime_disable(dev);
105}
106
107static 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
120static 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
130static DEFINE_SIMPLE_DEV_PM_OPS(tps6594_esm_pm_ops, tps6594_esm_suspend, tps6594_esm_resume);
131
132static 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
141module_platform_driver(tps6594_esm_driver);
142
143MODULE_ALIAS("platform:tps6594-esm");
144MODULE_AUTHOR("Julien Panis <jpanis@baylibre.com>");
145MODULE_DESCRIPTION("TPS6594 Error Signal Monitor Driver");
146MODULE_LICENSE("GPL");
147