xref: /openbmc/linux/drivers/mfd/bcm2835-pm.c (revision a44e4f3a)
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 
28 static int bcm2835_pm_probe(struct platform_device *pdev)
29 {
30 	struct resource *res;
31 	struct device *dev = &pdev->dev;
32 	struct bcm2835_pm *pm;
33 	int ret;
34 
35 	pm = devm_kzalloc(dev, sizeof(*pm), GFP_KERNEL);
36 	if (!pm)
37 		return -ENOMEM;
38 	platform_set_drvdata(pdev, pm);
39 
40 	pm->dev = dev;
41 
42 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
43 	pm->base = devm_ioremap_resource(dev, res);
44 	if (IS_ERR(pm->base))
45 		return PTR_ERR(pm->base);
46 
47 	ret = devm_mfd_add_devices(dev, -1,
48 				   bcm2835_pm_devs, ARRAY_SIZE(bcm2835_pm_devs),
49 				   NULL, 0, NULL);
50 	if (ret)
51 		return ret;
52 
53 	/* We'll use the presence of the AXI ASB regs in the
54 	 * bcm2835-pm binding as the key for whether we can reference
55 	 * the full PM register range and support power domains.
56 	 */
57 	res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
58 	if (res) {
59 		pm->asb = devm_ioremap_resource(dev, res);
60 		if (IS_ERR(pm->asb))
61 			return PTR_ERR(pm->asb);
62 
63 		ret = devm_mfd_add_devices(dev, -1,
64 					   bcm2835_power_devs,
65 					   ARRAY_SIZE(bcm2835_power_devs),
66 					   NULL, 0, NULL);
67 		if (ret)
68 			return ret;
69 	}
70 
71 	return 0;
72 }
73 
74 static const struct of_device_id bcm2835_pm_of_match[] = {
75 	{ .compatible = "brcm,bcm2835-pm-wdt", },
76 	{ .compatible = "brcm,bcm2835-pm", },
77 	{},
78 };
79 MODULE_DEVICE_TABLE(of, bcm2835_pm_of_match);
80 
81 static struct platform_driver bcm2835_pm_driver = {
82 	.probe		= bcm2835_pm_probe,
83 	.driver = {
84 		.name =	"bcm2835-pm",
85 		.of_match_table = bcm2835_pm_of_match,
86 	},
87 };
88 module_platform_driver(bcm2835_pm_driver);
89 
90 MODULE_AUTHOR("Eric Anholt <eric@anholt.net>");
91 MODULE_DESCRIPTION("Driver for Broadcom BCM2835 PM MFD");
92 MODULE_LICENSE("GPL");
93