xref: /linux/drivers/mfd/bcm2835-pm.c (revision 1ac731c529cd4d6adbce134754b51ff7d822b145)
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * PM MFD driver for Broadcom BCM2835
4  *
5  * This driver binds to the PM block and creates the MFD device for
6  * the WDT and power drivers.
7  */
8 
9 #include <linux/delay.h>
10 #include <linux/io.h>
11 #include <linux/mfd/bcm2835-pm.h>
12 #include <linux/mfd/core.h>
13 #include <linux/module.h>
14 #include <linux/of_address.h>
15 #include <linux/of_platform.h>
16 #include <linux/platform_device.h>
17 #include <linux/types.h>
18 #include <linux/watchdog.h>
19 
20 static const struct mfd_cell bcm2835_pm_devs[] = {
21 	{ .name = "bcm2835-wdt" },
22 };
23 
24 static const struct mfd_cell bcm2835_power_devs[] = {
25 	{ .name = "bcm2835-power" },
26 };
27 
bcm2835_pm_get_pdata(struct platform_device * pdev,struct bcm2835_pm * pm)28 static int bcm2835_pm_get_pdata(struct platform_device *pdev,
29 				struct bcm2835_pm *pm)
30 {
31 	if (of_property_present(pm->dev->of_node, "reg-names")) {
32 		struct resource *res;
33 
34 		pm->base = devm_platform_ioremap_resource_byname(pdev, "pm");
35 		if (IS_ERR(pm->base))
36 			return PTR_ERR(pm->base);
37 
38 		res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "asb");
39 		if (res) {
40 			pm->asb = devm_ioremap_resource(&pdev->dev, res);
41 			if (IS_ERR(pm->asb))
42 				pm->asb = NULL;
43 		}
44 
45 		res = platform_get_resource_byname(pdev, IORESOURCE_MEM,
46 						    "rpivid_asb");
47 		if (res) {
48 			pm->rpivid_asb = devm_ioremap_resource(&pdev->dev, res);
49 			if (IS_ERR(pm->rpivid_asb))
50 				pm->rpivid_asb = NULL;
51 		}
52 
53 		return 0;
54 	}
55 
56 	/* If no 'reg-names' property is found we can assume we're using old DTB. */
57 	pm->base = devm_platform_ioremap_resource(pdev, 0);
58 	if (IS_ERR(pm->base))
59 		return PTR_ERR(pm->base);
60 
61 	pm->asb = devm_platform_ioremap_resource(pdev, 1);
62 	if (IS_ERR(pm->asb))
63 		pm->asb = NULL;
64 
65 	pm->rpivid_asb = devm_platform_ioremap_resource(pdev, 2);
66 	if (IS_ERR(pm->rpivid_asb))
67 		pm->rpivid_asb = NULL;
68 
69 	return 0;
70 }
71 
bcm2835_pm_probe(struct platform_device * pdev)72 static int bcm2835_pm_probe(struct platform_device *pdev)
73 {
74 	struct device *dev = &pdev->dev;
75 	struct bcm2835_pm *pm;
76 	int ret;
77 
78 	pm = devm_kzalloc(dev, sizeof(*pm), GFP_KERNEL);
79 	if (!pm)
80 		return -ENOMEM;
81 	platform_set_drvdata(pdev, pm);
82 
83 	pm->dev = dev;
84 
85 	ret = bcm2835_pm_get_pdata(pdev, pm);
86 	if (ret)
87 		return ret;
88 
89 	ret = devm_mfd_add_devices(dev, -1,
90 				   bcm2835_pm_devs, ARRAY_SIZE(bcm2835_pm_devs),
91 				   NULL, 0, NULL);
92 	if (ret)
93 		return ret;
94 
95 	/*
96 	 * We'll use the presence of the AXI ASB regs in the
97 	 * bcm2835-pm binding as the key for whether we can reference
98 	 * the full PM register range and support power domains.
99 	 */
100 	if (pm->asb)
101 		return devm_mfd_add_devices(dev, -1, bcm2835_power_devs,
102 					    ARRAY_SIZE(bcm2835_power_devs),
103 					    NULL, 0, NULL);
104 	return 0;
105 }
106 
107 static const struct of_device_id bcm2835_pm_of_match[] = {
108 	{ .compatible = "brcm,bcm2835-pm-wdt", },
109 	{ .compatible = "brcm,bcm2835-pm", },
110 	{ .compatible = "brcm,bcm2711-pm", },
111 	{},
112 };
113 MODULE_DEVICE_TABLE(of, bcm2835_pm_of_match);
114 
115 static struct platform_driver bcm2835_pm_driver = {
116 	.probe		= bcm2835_pm_probe,
117 	.driver = {
118 		.name =	"bcm2835-pm",
119 		.of_match_table = bcm2835_pm_of_match,
120 	},
121 };
122 module_platform_driver(bcm2835_pm_driver);
123 
124 MODULE_AUTHOR("Eric Anholt <eric@anholt.net>");
125 MODULE_DESCRIPTION("Driver for Broadcom BCM2835 PM MFD");
126