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/module.h>
  24 #include <linux/slab.h>
  25 #include <linux/platform_device.h>
  26 #include <linux/mfd/twl6040.h>
  27 #include <linux/clk-provider.h>
  28
  29 struct twl6040_pdmclk {
  30         struct twl6040 *twl6040;
  31         struct device *dev;
  32         struct clk_hw pdmclk_hw;
  33         int enabled;
  34 };
  35
  36 static int twl6040_pdmclk_is_prepared(struct clk_hw *hw)
  37 {
  38         struct twl6040_pdmclk *pdmclk = container_of(hw, struct twl6040_pdmclk,
  39                                                      pdmclk_hw);
  40
  41         return pdmclk->enabled;
  42 }
  43
  44 static int twl6040_pdmclk_prepare(struct clk_hw *hw)
  45 {
  46         struct twl6040_pdmclk *pdmclk = container_of(hw, struct twl6040_pdmclk,
  47                                                      pdmclk_hw);
  48         int ret;
  49
  50         ret = twl6040_power(pdmclk->twl6040, 1);
  51         if (!ret)
  52                 pdmclk->enabled = 1;
  53
  54         return ret;
  55 }
  56
  57 static void twl6040_pdmclk_unprepare(struct clk_hw *hw)
  58 {
  59         struct twl6040_pdmclk *pdmclk = container_of(hw, struct twl6040_pdmclk,
  60                                                      pdmclk_hw);
  61         int ret;
  62
  63         ret = twl6040_power(pdmclk->twl6040, 0);
  64         if (!ret)
  65                 pdmclk->enabled = 0;
  66
  67 }
  68
  69 static unsigned long twl6040_pdmclk_recalc_rate(struct clk_hw *hw,
  70                                                 unsigned long parent_rate)
  71 {
  72         struct twl6040_pdmclk *pdmclk = container_of(hw, struct twl6040_pdmclk,
  73                                                      pdmclk_hw);
  74
  75         return twl6040_get_sysclk(pdmclk->twl6040);
  76 }
  77
  78 static const struct clk_ops twl6040_pdmclk_ops = {
  79         .is_prepared = twl6040_pdmclk_is_prepared,
  80         .prepare = twl6040_pdmclk_prepare,
  81         .unprepare = twl6040_pdmclk_unprepare,
  82         .recalc_rate = twl6040_pdmclk_recalc_rate,
  83 };
  84
  85 static const struct clk_init_data twl6040_pdmclk_init = {
  86         .name = "pdmclk",
  87         .ops = &twl6040_pdmclk_ops,
  88         .flags = CLK_GET_RATE_NOCACHE,
  89 };
  90
  91 static int twl6040_pdmclk_probe(struct platform_device *pdev)
  92 {
  93         struct twl6040 *twl6040 = dev_get_drvdata(pdev->dev.parent);
  94         struct twl6040_pdmclk *clkdata;
  95         int ret;
  96
  97         clkdata = devm_kzalloc(&pdev->dev, sizeof(*clkdata), GFP_KERNEL);
  98         if (!clkdata)
  99                 return -ENOMEM;
 100
 101         clkdata->dev = &pdev->dev;
 102         clkdata->twl6040 = twl6040;
 103
 104         clkdata->pdmclk_hw.init = &twl6040_pdmclk_init;
 105         ret = devm_clk_hw_register(&pdev->dev, &clkdata->pdmclk_hw);
 106         if (ret)
 107                 return ret;
 108
 109         platform_set_drvdata(pdev, clkdata);
 110
 111         return of_clk_add_hw_provider(pdev->dev.parent->of_node,
 112                                       of_clk_hw_simple_get,
 113                                       &clkdata->pdmclk_hw);
 114 }
 115
 116 static struct platform_driver twl6040_pdmclk_driver = {
 117         .driver = {
 118                 .name = "twl6040-pdmclk",
 119         },
 120         .probe = twl6040_pdmclk_probe,
 121 };
 122
 123 module_platform_driver(twl6040_pdmclk_driver);
 124
 125 MODULE_DESCRIPTION("TWL6040 clock driver for McPDM functional clock");
 126 MODULE_AUTHOR("Peter Ujfalusi <peter.ujfalusi@ti.com>");
 127 MODULE_ALIAS("platform:twl6040-pdmclk");
 128 MODULE_LICENSE("GPL");