drivers/clk/bcm/clk-bcm2835-aux.c

   1 /*
   2  * Copyright (C) 2015 Broadcom
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License as published by
   6  * the Free Software Foundation; either version 2 of the License, or
   7  * (at your option) any later version.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  */
  14
  15 #include <linux/clk.h>
  16 #include <linux/clk-provider.h>
  17 #include <linux/clk/bcm2835.h>
  18 #include <linux/module.h>
  19 #include <linux/platform_device.h>
  20 #include <dt-bindings/clock/bcm2835-aux.h>
  21
  22 #define BCM2835_AUXIRQ          0x00
  23 #define BCM2835_AUXENB          0x04
  24
  25 static int bcm2835_aux_clk_probe(struct platform_device *pdev)
  26 {
  27         struct device *dev = &pdev->dev;
  28         struct clk_onecell_data *onecell;
  29         const char *parent;
  30         struct clk *parent_clk;
  31         struct resource *res;
  32         void __iomem *reg, *gate;
  33
  34         parent_clk = devm_clk_get(dev, NULL);
  35         if (IS_ERR(parent_clk))
  36                 return PTR_ERR(parent_clk);
  37         parent = __clk_get_name(parent_clk);
  38
  39         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
  40         reg = devm_ioremap_resource(dev, res);
  41         if (!reg)
  42                 return -ENODEV;
  43
  44         onecell = devm_kmalloc(dev, sizeof(*onecell), GFP_KERNEL);
  45         if (!onecell)
  46                 return -ENOMEM;
  47         onecell->clk_num = BCM2835_AUX_CLOCK_COUNT;
  48         onecell->clks = devm_kcalloc(dev, BCM2835_AUX_CLOCK_COUNT,
  49                                      sizeof(*onecell->clks), GFP_KERNEL);
  50         if (!onecell->clks)
  51                 return -ENOMEM;
  52
  53         gate = reg + BCM2835_AUXENB;
  54         onecell->clks[BCM2835_AUX_CLOCK_UART] =
  55                 clk_register_gate(dev, "aux_uart", parent, 0, gate, 0, 0, NULL);
  56
  57         onecell->clks[BCM2835_AUX_CLOCK_SPI1] =
  58                 clk_register_gate(dev, "aux_spi1", parent, 0, gate, 1, 0, NULL);
  59
  60         onecell->clks[BCM2835_AUX_CLOCK_SPI2] =
  61                 clk_register_gate(dev, "aux_spi2", parent, 0, gate, 2, 0, NULL);
  62
  63         of_clk_add_provider(pdev->dev.of_node, of_clk_src_onecell_get, onecell);
  64
  65         return 0;
  66 }
  67
  68 static const struct of_device_id bcm2835_aux_clk_of_match[] = {
  69         { .compatible = "brcm,bcm2835-aux", },
  70         {},
  71 };
  72 MODULE_DEVICE_TABLE(of, bcm2835_aux_clk_of_match);
  73
  74 static struct platform_driver bcm2835_aux_clk_driver = {
  75         .driver = {
  76                 .name = "bcm2835-aux-clk",
  77                 .of_match_table = bcm2835_aux_clk_of_match,
  78         },
  79         .probe          = bcm2835_aux_clk_probe,
  80 };
  81 builtin_platform_driver(bcm2835_aux_clk_driver);
  82
  83 MODULE_AUTHOR("Eric Anholt <eric@anholt.net>");
  84 MODULE_DESCRIPTION("BCM2835 auxiliary peripheral clock driver");
  85 MODULE_LICENSE("GPL v2");