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(dev: 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(map: tps->regmap, TPS6594_REG_DEV_REV, val: &rev);
49 if (ret)
50 return dev_err_probe(dev, err: ret,
51 fmt: "Failed to read PMIC revision\n");
52 if (rev == TPS6594_DEV_REV_1)
53 return dev_err_probe(dev, err: -ENODEV,
54 fmt: "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 thread_fn: tps6594_esm_isr, IRQF_ONESHOT,
63 devname: pdev->resource[i].name, dev_id: pdev);
64 if (ret)
65 return dev_err_probe(dev, err: ret, fmt: "Failed to request irq\n");
66 }
67
68 ret = regmap_set_bits(map: 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, err: ret, fmt: "Failed to configure ESM\n");
72
73 ret = regmap_set_bits(map: tps->regmap, TPS6594_REG_ESM_SOC_START_REG,
74 TPS6594_BIT_ESM_SOC_START);
75 if (ret)
76 return dev_err_probe(dev, err: ret, fmt: "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(dev: pdev->dev.parent);
87 struct device *dev = &pdev->dev;
88 int ret;
89
90 ret = regmap_clear_bits(map: 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(map: 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: dev->parent);
110 int ret;
111
112 ret = regmap_clear_bits(map: 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: dev->parent);
123
124 pm_runtime_get_sync(dev);
125
126 return regmap_set_bits(map: 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 = 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

source code of linux/drivers/misc/tps6594-esm.c