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
 19void 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
 25void 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
 32static 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
 40static 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
 59struct 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
 97err_node_put:
 98	of_node_put(np);
 99	return NULL;
100}
101
102void fsl_tcon_free(struct fsl_tcon *tcon)
103{
104	clk_disable_unprepare(tcon->ipg_clk);
105	clk_put(tcon->ipg_clk);
106}
107