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_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");