drivers/gpu/drm/fsl-dcu/fsl_tcon.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * Copyright 2015 Toradex AG
   4  *
   5  * Stefan Agner <stefan@agner.ch>
   6  *
   7  * Freescale TCON device driver
   8  */
   9
  10 #include <linux/clk.h>
  11 #include <linux/io.h>
  12 #include <linux/mm.h>
  13 #include <linux/of_address.h>
  14 #include <linux/platform_device.h>
  15 #include <linux/regmap.h>
  16
  17 #include "fsl_tcon.h"
  18
  19 void fsl_tcon_bypass_disable(struct fsl_tcon *tcon)
  20 {
  21         regmap_update_bits(tcon->regs, FSL_TCON_CTRL1,
  22                            FSL_TCON_CTRL1_TCON_BYPASS, 0);
  23 }
  24
  25 void fsl_tcon_bypass_enable(struct fsl_tcon *tcon)
  26 {
  27         regmap_update_bits(tcon->regs, FSL_TCON_CTRL1,
  28                            FSL_TCON_CTRL1_TCON_BYPASS,
  29                            FSL_TCON_CTRL1_TCON_BYPASS);
  30 }
  31
  32 static struct regmap_config fsl_tcon_regmap_config = {
  33         .reg_bits = 32,
  34         .reg_stride = 4,
  35         .val_bits = 32,
  36
  37         .name = "tcon",
  38 };
  39
  40 static int fsl_tcon_init_regmap(struct device *dev,
  41                                 struct fsl_tcon *tcon,
  42                                 struct device_node *np)
  43 {
  44         struct resource res;
  45         void __iomem *regs;
  46
  47         if (of_address_to_resource(np, 0, &res))
  48                 return -EINVAL;
  49
  50         regs = devm_ioremap_resource(dev, &res);
  51         if (IS_ERR(regs))
  52                 return PTR_ERR(regs);
  53
  54         tcon->regs = devm_regmap_init_mmio(dev, regs,
  55                                            &fsl_tcon_regmap_config);
  56         return PTR_ERR_OR_ZERO(tcon->regs);
  57 }
  58
  59 struct fsl_tcon *fsl_tcon_init(struct device *dev)
  60 {
  61         struct fsl_tcon *tcon;
  62         struct device_node *np;
  63         int ret;
  64
  65         /* TCON node is not mandatory, some devices do not provide TCON */
  66         np = of_parse_phandle(dev->of_node, "fsl,tcon", 0);
  67         if (!np)
  68                 return NULL;
  69
  70         tcon = devm_kzalloc(dev, sizeof(*tcon), GFP_KERNEL);
  71         if (!tcon)
  72                 goto err_node_put;
  73
  74         ret = fsl_tcon_init_regmap(dev, tcon, np);
  75         if (ret) {
  76                 dev_err(dev, "Couldn't create the TCON regmap\n");
  77                 goto err_node_put;
  78         }
  79
  80         tcon->ipg_clk = of_clk_get_by_name(np, "ipg");
  81         if (IS_ERR(tcon->ipg_clk)) {
  82                 dev_err(dev, "Couldn't get the TCON bus clock\n");
  83                 goto err_node_put;
  84         }
  85
  86         ret = clk_prepare_enable(tcon->ipg_clk);
  87         if (ret) {
  88                 dev_err(dev, "Couldn't enable the TCON clock\n");
  89                 goto err_node_put;
  90         }
  91
  92         of_node_put(np);
  93         dev_info(dev, "Using TCON in bypass mode\n");
  94
  95         return tcon;
  96
  97 err_node_put:
  98         of_node_put(np);
  99         return NULL;
 100 }
 101
 102 void fsl_tcon_free(struct fsl_tcon *tcon)
 103 {
 104         clk_disable_unprepare(tcon->ipg_clk);
 105         clk_put(tcon->ipg_clk);
 106 }
 107