drivers/mfd/bcm2835-pm.c

   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_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
  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");