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
108