power/reset/qcom-pon.c

0001 // SPDX-License-Identifier: GPL-2.0
0002 // Copyright (c) 2017-18 Linaro Limited
0003
0004 #include <linux/delay.h>
0005 #include <linux/errno.h>
0006 #include <linux/kernel.h>
0007 #include <linux/module.h>
0008 #include <linux/of.h>
0009 #include <linux/of_platform.h>
0010 #include <linux/platform_device.h>
0011 #include <linux/reboot.h>
0012 #include <linux/reboot-mode.h>
0013 #include <linux/regmap.h>
0014
0015 #define PON_SOFT_RB_SPARE       0x8f
0016
0017 #define GEN1_REASON_SHIFT       2
0018 #define GEN2_REASON_SHIFT       1
0019
0020 struct pm8916_pon {
0021     struct device *dev;
0022     struct regmap *regmap;
0023     u32 baseaddr;
0024     struct reboot_mode_driver reboot_mode;
0025     long reason_shift;
0026 };
0027
0028 static int pm8916_reboot_mode_write(struct reboot_mode_driver *reboot,
0029                     unsigned int magic)
0030 {
0031     struct pm8916_pon *pon = container_of
0032             (reboot, struct pm8916_pon, reboot_mode);
0033     int ret;
0034
0035     ret = regmap_update_bits(pon->regmap,
0036                  pon->baseaddr + PON_SOFT_RB_SPARE,
0037                  GENMASK(7, pon->reason_shift),
0038                  magic << pon->reason_shift);
0039     if (ret < 0)
0040         dev_err(pon->dev, "update reboot mode bits failed\n");
0041
0042     return ret;
0043 }
0044
0045 static int pm8916_pon_probe(struct platform_device *pdev)
0046 {
0047     struct pm8916_pon *pon;
0048     int error;
0049
0050     pon = devm_kzalloc(&pdev->dev, sizeof(*pon), GFP_KERNEL);
0051     if (!pon)
0052         return -ENOMEM;
0053
0054     pon->dev = &pdev->dev;
0055
0056     pon->regmap = dev_get_regmap(pdev->dev.parent, NULL);
0057     if (!pon->regmap) {
0058         dev_err(&pdev->dev, "failed to locate regmap\n");
0059         return -ENODEV;
0060     }
0061
0062     error = of_property_read_u32(pdev->dev.of_node, "reg",
0063                      &pon->baseaddr);
0064     if (error)
0065         return error;
0066
0067     pon->reboot_mode.dev = &pdev->dev;
0068     pon->reason_shift = (long)of_device_get_match_data(&pdev->dev);
0069     pon->reboot_mode.write = pm8916_reboot_mode_write;
0070     error = devm_reboot_mode_register(&pdev->dev, &pon->reboot_mode);
0071     if (error) {
0072         dev_err(&pdev->dev, "can't register reboot mode\n");
0073         return error;
0074     }
0075
0076     platform_set_drvdata(pdev, pon);
0077
0078     return devm_of_platform_populate(&pdev->dev);
0079 }
0080
0081 static const struct of_device_id pm8916_pon_id_table[] = {
0082     { .compatible = "qcom,pm8916-pon", .data = (void *)GEN1_REASON_SHIFT },
0083     { .compatible = "qcom,pms405-pon", .data = (void *)GEN1_REASON_SHIFT },
0084     { .compatible = "qcom,pm8998-pon", .data = (void *)GEN2_REASON_SHIFT },
0085     { }
0086 };
0087 MODULE_DEVICE_TABLE(of, pm8916_pon_id_table);
0088
0089 static struct platform_driver pm8916_pon_driver = {
0090     .probe = pm8916_pon_probe,
0091     .driver = {
0092         .name = "pm8916-pon",
0093         .of_match_table = of_match_ptr(pm8916_pon_id_table),
0094     },
0095 };
0096 module_platform_driver(pm8916_pon_driver);
0097
0098 MODULE_DESCRIPTION("pm8916 Power On driver");
0099 MODULE_LICENSE("GPL v2");