drivers/clk/clk-twl6040.c

   1 /*
   2 * TWL6040 clock module driver for OMAP4 McPDM functional clock
   3 *
   4 * Copyright (C) 2012 Texas Instruments Inc.
   5 * Peter Ujfalusi <peter.ujfalusi@ti.com>
   6 *
   7 * This program is free software; you can redistribute it and/or
   8 * modify it under the terms of the GNU General Public License
   9 * version 2 as published by the Free Software Foundation.
  10 *
  11 * This program is distributed in the hope that it will be useful, but
  12 * WITHOUT ANY WARRANTY; without even the implied warranty of
  13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  14 * General Public License for more details.
  15 *
  16 * You should have received a copy of the GNU General Public License
  17 * along with this program; if not, write to the Free Software
  18 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
  19 * 02110-1301 USA
  20 *
  21 */
  22
  23 #include <linux/clk.h>
  24 #include <linux/module.h>
  25 #include <linux/slab.h>
  26 #include <linux/platform_device.h>
  27 #include <linux/mfd/twl6040.h>
  28 #include <linux/clk-provider.h>
  29
  30 struct twl6040_clk {
  31         struct twl6040 *twl6040;
  32         struct device *dev;
  33         struct clk_hw mcpdm_fclk;
  34         struct clk *clk;
  35         int enabled;
  36 };
  37
  38 static int twl6040_bitclk_is_enabled(struct clk_hw *hw)
  39 {
  40         struct twl6040_clk *twl6040_clk = container_of(hw, struct twl6040_clk,
  41                                                        mcpdm_fclk);
  42         return twl6040_clk->enabled;
  43 }
  44
  45 static int twl6040_bitclk_prepare(struct clk_hw *hw)
  46 {
  47         struct twl6040_clk *twl6040_clk = container_of(hw, struct twl6040_clk,
  48                                                        mcpdm_fclk);
  49         int ret;
  50
  51         ret = twl6040_power(twl6040_clk->twl6040, 1);
  52         if (!ret)
  53                 twl6040_clk->enabled = 1;
  54
  55         return ret;
  56 }
  57
  58 static void twl6040_bitclk_unprepare(struct clk_hw *hw)
  59 {
  60         struct twl6040_clk *twl6040_clk = container_of(hw, struct twl6040_clk,
  61                                                        mcpdm_fclk);
  62         int ret;
  63
  64         ret = twl6040_power(twl6040_clk->twl6040, 0);
  65         if (!ret)
  66                 twl6040_clk->enabled = 0;
  67 }
  68
  69 static const struct clk_ops twl6040_mcpdm_ops = {
  70         .is_enabled = twl6040_bitclk_is_enabled,
  71         .prepare = twl6040_bitclk_prepare,
  72         .unprepare = twl6040_bitclk_unprepare,
  73 };
  74
  75 static struct clk_init_data wm831x_clkout_init = {
  76         .name = "mcpdm_fclk",
  77         .ops = &twl6040_mcpdm_ops,
  78         .flags = CLK_IS_ROOT,
  79 };
  80
  81 static int twl6040_clk_probe(struct platform_device *pdev)
  82 {
  83         struct twl6040 *twl6040 = dev_get_drvdata(pdev->dev.parent);
  84         struct twl6040_clk *clkdata;
  85
  86         clkdata = devm_kzalloc(&pdev->dev, sizeof(*clkdata), GFP_KERNEL);
  87         if (!clkdata)
  88                 return -ENOMEM;
  89
  90         clkdata->dev = &pdev->dev;
  91         clkdata->twl6040 = twl6040;
  92
  93         clkdata->mcpdm_fclk.init = &wm831x_clkout_init;
  94         clkdata->clk = clk_register(&pdev->dev, &clkdata->mcpdm_fclk);
  95         if (IS_ERR(clkdata->clk))
  96                 return PTR_ERR(clkdata->clk);
  97
  98         dev_set_drvdata(&pdev->dev, clkdata);
  99
 100         return 0;
 101 }
 102
 103 static int twl6040_clk_remove(struct platform_device *pdev)
 104 {
 105         struct twl6040_clk *clkdata = dev_get_drvdata(&pdev->dev);
 106
 107         clk_unregister(clkdata->clk);
 108
 109         return 0;
 110 }
 111
 112 static struct platform_driver twl6040_clk_driver = {
 113         .driver = {
 114                 .name = "twl6040-clk",
 115                 .owner = THIS_MODULE,
 116         },
 117         .probe = twl6040_clk_probe,
 118         .remove = twl6040_clk_remove,
 119 };
 120
 121 module_platform_driver(twl6040_clk_driver);
 122
 123 MODULE_DESCRIPTION("TWL6040 clock driver for McPDM functional clock");
 124 MODULE_AUTHOR("Peter Ujfalusi <peter.ujfalusi@ti.com>");
 125 MODULE_ALIAS("platform:twl6040-clk");
 126 MODULE_LICENSE("GPL");