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 const struct of_device_id bcm2835_pm_of_match[] = {
  73         { .compatible = "brcm,bcm2835-pm-wdt", },
  74         { .compatible = "brcm,bcm2835-pm", },
  75         { .compatible = "brcm,bcm2711-pm", },
  76         { .compatible = "brcm,bcm2712-pm", .data = (const void *)1},
  77         {},
  78 };
  79 MODULE_DEVICE_TABLE(of, bcm2835_pm_of_match);
  80
  81 static int bcm2835_pm_probe(struct platform_device *pdev)
  82 {
  83         const struct of_device_id *of_id;
  84         struct device *dev = &pdev->dev;
  85         struct bcm2835_pm *pm;
  86         bool is_2712;
  87         int ret;
  88
  89         of_id = of_match_node(bcm2835_pm_of_match, pdev->dev.of_node);
  90         if (!of_id) {
  91                 dev_err(&pdev->dev, "Failed to match compatible string\n");
  92                 return -EINVAL;
  93         }
  94         is_2712 = !!of_id->data;
  95
  96         pm = devm_kzalloc(dev, sizeof(*pm), GFP_KERNEL);
  97         if (!pm)
  98                 return -ENOMEM;
  99         platform_set_drvdata(pdev, pm);
 100
 101         pm->dev = dev;
 102
 103         ret = bcm2835_pm_get_pdata(pdev, pm);
 104         if (ret)
 105                 return ret;
 106
 107         ret = devm_mfd_add_devices(dev, -1,
 108                                    bcm2835_pm_devs, ARRAY_SIZE(bcm2835_pm_devs),
 109                                    NULL, 0, NULL);
 110         if (ret)
 111                 return ret;
 112
 113         /*
 114          * We'll use the presence of the AXI ASB regs in the
 115          * bcm2835-pm binding as the key for whether we can reference
 116          * the full PM register range and support power domains.
 117          */
 118         if (pm->asb || is_2712)
 119                 return devm_mfd_add_devices(dev, -1, bcm2835_power_devs,
 120                                             ARRAY_SIZE(bcm2835_power_devs),
 121                                             NULL, 0, NULL);
 122         return 0;
 123 }
 124
 125 static struct platform_driver bcm2835_pm_driver = {
 126         .probe          = bcm2835_pm_probe,
 127         .driver = {
 128                 .name = "bcm2835-pm",
 129                 .of_match_table = bcm2835_pm_of_match,
 130         },
 131 };
 132 module_platform_driver(bcm2835_pm_driver);
 133
 134 MODULE_AUTHOR("Eric Anholt <eric@anholt.net>");
 135 MODULE_DESCRIPTION("Driver for Broadcom BCM2835 PM MFD");