LXR linux/drivers/gpu/drm/fsl-dcu/fsl

   1/*
   2 * Copyright 2015 Toradex AG
   3 *
   4 * Stefan Agner <stefan@agner.ch>
   5 *
   6 * Freescale TCON device driver
   7 *
   8 * This program is free software; you can redistribute it and/or modify
   9 * it under the terms of the GNU General Public License as published by
  10 * the Free Software Foundation; either version 2 of the License, or
  11 * (at your option) any later version.
  12 */
  13
  14#include <linux/clk.h>
  15#include <linux/io.h>
  16#include <linux/mm.h>
  17#include <linux/of_address.h>
  18#include <linux/platform_device.h>
  19#include <linux/regmap.h>
  20
  21#include "fsl_tcon.h"
  22
  23void fsl_tcon_bypass_disable(struct fsl_tcon *tcon)
  24{
  25        regmap_update_bits(tcon->regs, FSL_TCON_CTRL1,
  26                           FSL_TCON_CTRL1_TCON_BYPASS, 0);
  27}
  28
  29void fsl_tcon_bypass_enable(struct fsl_tcon *tcon)
  30{
  31        regmap_update_bits(tcon->regs, FSL_TCON_CTRL1,
  32                           FSL_TCON_CTRL1_TCON_BYPASS,
  33                           FSL_TCON_CTRL1_TCON_BYPASS);
  34}
  35
  36static struct regmap_config fsl_tcon_regmap_config = {
  37        .reg_bits = 32,
  38        .reg_stride = 4,
  39        .val_bits = 32,
  40
  41        .name = "tcon",
  42};
  43
  44static int fsl_tcon_init_regmap(struct device *dev,
  45                                struct fsl_tcon *tcon,
  46                                struct device_node *np)
  47{
  48        struct resource res;
  49        void __iomem *regs;
  50
  51        if (of_address_to_resource(np, 0, &res))
  52                return -EINVAL;
  53
  54        regs = devm_ioremap_resource(dev, &res);
  55        if (IS_ERR(regs))
  56                return PTR_ERR(regs);
  57
  58        tcon->regs = devm_regmap_init_mmio(dev, regs,
  59                                           &fsl_tcon_regmap_config);
  60        if (IS_ERR(tcon->regs))
  61                return PTR_ERR(tcon->regs);
  62
  63        return 0;
  64}
  65
  66struct fsl_tcon *fsl_tcon_init(struct device *dev)
  67{
  68        struct fsl_tcon *tcon;
  69        struct device_node *np;
  70        int ret;
  71
  72        /* TCON node is not mandatory, some devices do not provide TCON */
  73        np = of_parse_phandle(dev->of_node, "fsl,tcon", 0);
  74        if (!np)
  75                return NULL;
  76
  77        tcon = devm_kzalloc(dev, sizeof(*tcon), GFP_KERNEL);
  78        if (!tcon) {
  79                ret = -ENOMEM;
  80                goto err_node_put;
  81        }
  82
  83        ret = fsl_tcon_init_regmap(dev, tcon, np);
  84        if (ret) {
  85                dev_err(dev, "Couldn't create the TCON regmap\n");
  86                goto err_node_put;
  87        }
  88
  89        tcon->ipg_clk = of_clk_get_by_name(np, "ipg");
  90        if (IS_ERR(tcon->ipg_clk)) {
  91                dev_err(dev, "Couldn't get the TCON bus clock\n");
  92                goto err_node_put;
  93        }
  94
  95        clk_prepare_enable(tcon->ipg_clk);
  96
  97        dev_info(dev, "Using TCON in bypass mode\n");
  98
  99        return tcon;
 100
 101err_node_put:
 102        of_node_put(np);
 103        return NULL;
 104}
 105
 106void fsl_tcon_free(struct fsl_tcon *tcon)
 107{
 108        clk_disable_unprepare(tcon->ipg_clk);
 109        clk_put(tcon->ipg_clk);
 110}
 111
 112