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
fsl_tcon_bypass_disable(struct fsl_tcon * tcon)23 void 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
fsl_tcon_bypass_enable(struct fsl_tcon * tcon)29 void 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
36 static 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
fsl_tcon_init_regmap(struct device * dev,struct fsl_tcon * tcon,struct device_node * np)44 static 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 return PTR_ERR_OR_ZERO(tcon->regs);
61 }
62
fsl_tcon_init(struct device * dev)63 struct fsl_tcon *fsl_tcon_init(struct device *dev)
64 {
65 struct fsl_tcon *tcon;
66 struct device_node *np;
67 int ret;
68
69 /* TCON node is not mandatory, some devices do not provide TCON */
70 np = of_parse_phandle(dev->of_node, "fsl,tcon", 0);
71 if (!np)
72 return NULL;
73
74 tcon = devm_kzalloc(dev, sizeof(*tcon), GFP_KERNEL);
75 if (!tcon) {
76 ret = -ENOMEM;
77 goto err_node_put;
78 }
79
80 ret = fsl_tcon_init_regmap(dev, tcon, np);
81 if (ret) {
82 dev_err(dev, "Couldn't create the TCON regmap\n");
83 goto err_node_put;
84 }
85
86 tcon->ipg_clk = of_clk_get_by_name(np, "ipg");
87 if (IS_ERR(tcon->ipg_clk)) {
88 dev_err(dev, "Couldn't get the TCON bus clock\n");
89 goto err_node_put;
90 }
91
92 ret = clk_prepare_enable(tcon->ipg_clk);
93 if (ret) {
94 dev_err(dev, "Couldn't enable the TCON clock\n");
95 goto err_node_put;
96 }
97
98 of_node_put(np);
99 dev_info(dev, "Using TCON in bypass mode\n");
100
101 return tcon;
102
103 err_node_put:
104 of_node_put(np);
105 return NULL;
106 }
107
fsl_tcon_free(struct fsl_tcon * tcon)108 void fsl_tcon_free(struct fsl_tcon *tcon)
109 {
110 clk_disable_unprepare(tcon->ipg_clk);
111 clk_put(tcon->ipg_clk);
112 }
113
114