1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright (c) 2018 HiSilicon Technologies Co., Ltd.
4  */
5 
6 #include <linux/clk.h>
7 #include <linux/mfd/syscon.h>
8 #include <linux/mmc/host.h>
9 #include <linux/module.h>
10 #include <linux/of_address.h>
11 #include <linux/platform_device.h>
12 #include <linux/pm_runtime.h>
13 #include <linux/regmap.h>
14 #include <linux/regulator/consumer.h>
15 
16 #include "dw_mmc.h"
17 #include "dw_mmc-pltfm.h"
18 
19 #define ALL_INT_CLR		0x1ffff
20 
21 struct hi3798cv200_priv {
22 	struct clk *sample_clk;
23 	struct clk *drive_clk;
24 };
25 
26 static void dw_mci_hi3798cv200_set_ios(struct dw_mci *host, struct mmc_ios *ios)
27 {
28 	struct hi3798cv200_priv *priv = host->priv;
29 	u32 val;
30 
31 	val = mci_readl(host, UHS_REG);
32 	if (ios->timing == MMC_TIMING_MMC_DDR52 ||
33 	    ios->timing == MMC_TIMING_UHS_DDR50)
34 		val |= SDMMC_UHS_DDR;
35 	else
36 		val &= ~SDMMC_UHS_DDR;
37 	mci_writel(host, UHS_REG, val);
38 
39 	val = mci_readl(host, ENABLE_SHIFT);
40 	if (ios->timing == MMC_TIMING_MMC_DDR52)
41 		val |= SDMMC_ENABLE_PHASE;
42 	else
43 		val &= ~SDMMC_ENABLE_PHASE;
44 	mci_writel(host, ENABLE_SHIFT, val);
45 
46 	val = mci_readl(host, DDR_REG);
47 	if (ios->timing == MMC_TIMING_MMC_HS400)
48 		val |= SDMMC_DDR_HS400;
49 	else
50 		val &= ~SDMMC_DDR_HS400;
51 	mci_writel(host, DDR_REG, val);
52 
53 	if (ios->timing == MMC_TIMING_MMC_HS ||
54 	    ios->timing == MMC_TIMING_LEGACY)
55 		clk_set_phase(priv->drive_clk, 180);
56 	else if (ios->timing == MMC_TIMING_MMC_HS200)
57 		clk_set_phase(priv->drive_clk, 135);
58 }
59 
60 static int dw_mci_hi3798cv200_execute_tuning(struct dw_mci_slot *slot,
61 					     u32 opcode)
62 {
63 	static const int degrees[] = { 0, 45, 90, 135, 180, 225, 270, 315 };
64 	struct dw_mci *host = slot->host;
65 	struct hi3798cv200_priv *priv = host->priv;
66 	int raise_point = -1, fall_point = -1;
67 	int err, prev_err = -1;
68 	int found = 0;
69 	int i;
70 
71 	for (i = 0; i < ARRAY_SIZE(degrees); i++) {
72 		clk_set_phase(priv->sample_clk, degrees[i]);
73 		mci_writel(host, RINTSTS, ALL_INT_CLR);
74 
75 		err = mmc_send_tuning(slot->mmc, opcode, NULL);
76 		if (!err)
77 			found = 1;
78 
79 		if (i > 0) {
80 			if (err && !prev_err)
81 				fall_point = i - 1;
82 			if (!err && prev_err)
83 				raise_point = i;
84 		}
85 
86 		if (raise_point != -1 && fall_point != -1)
87 			goto tuning_out;
88 
89 		prev_err = err;
90 		err = 0;
91 	}
92 
93 tuning_out:
94 	if (found) {
95 		if (raise_point == -1)
96 			raise_point = 0;
97 		if (fall_point == -1)
98 			fall_point = ARRAY_SIZE(degrees) - 1;
99 		if (fall_point < raise_point) {
100 			if ((raise_point + fall_point) >
101 			    (ARRAY_SIZE(degrees) - 1))
102 				i = fall_point / 2;
103 			else
104 				i = (raise_point + ARRAY_SIZE(degrees) - 1) / 2;
105 		} else {
106 			i = (raise_point + fall_point) / 2;
107 		}
108 
109 		clk_set_phase(priv->sample_clk, degrees[i]);
110 		dev_dbg(host->dev, "Tuning clk_sample[%d, %d], set[%d]\n",
111 			raise_point, fall_point, degrees[i]);
112 	} else {
113 		dev_err(host->dev, "No valid clk_sample shift! use default\n");
114 		err = -EINVAL;
115 	}
116 
117 	mci_writel(host, RINTSTS, ALL_INT_CLR);
118 	return err;
119 }
120 
121 static int dw_mci_hi3798cv200_init(struct dw_mci *host)
122 {
123 	struct hi3798cv200_priv *priv;
124 	int ret;
125 
126 	priv = devm_kzalloc(host->dev, sizeof(*priv), GFP_KERNEL);
127 	if (!priv)
128 		return -ENOMEM;
129 
130 	priv->sample_clk = devm_clk_get(host->dev, "ciu-sample");
131 	if (IS_ERR(priv->sample_clk)) {
132 		dev_err(host->dev, "failed to get ciu-sample clock\n");
133 		return PTR_ERR(priv->sample_clk);
134 	}
135 
136 	priv->drive_clk = devm_clk_get(host->dev, "ciu-drive");
137 	if (IS_ERR(priv->drive_clk)) {
138 		dev_err(host->dev, "failed to get ciu-drive clock\n");
139 		return PTR_ERR(priv->drive_clk);
140 	}
141 
142 	ret = clk_prepare_enable(priv->sample_clk);
143 	if (ret) {
144 		dev_err(host->dev, "failed to enable ciu-sample clock\n");
145 		return ret;
146 	}
147 
148 	ret = clk_prepare_enable(priv->drive_clk);
149 	if (ret) {
150 		dev_err(host->dev, "failed to enable ciu-drive clock\n");
151 		goto disable_sample_clk;
152 	}
153 
154 	host->priv = priv;
155 	return 0;
156 
157 disable_sample_clk:
158 	clk_disable_unprepare(priv->sample_clk);
159 	return ret;
160 }
161 
162 static const struct dw_mci_drv_data hi3798cv200_data = {
163 	.common_caps = MMC_CAP_CMD23,
164 	.init = dw_mci_hi3798cv200_init,
165 	.set_ios = dw_mci_hi3798cv200_set_ios,
166 	.execute_tuning = dw_mci_hi3798cv200_execute_tuning,
167 };
168 
169 static int dw_mci_hi3798cv200_probe(struct platform_device *pdev)
170 {
171 	return dw_mci_pltfm_register(pdev, &hi3798cv200_data);
172 }
173 
174 static int dw_mci_hi3798cv200_remove(struct platform_device *pdev)
175 {
176 	struct dw_mci *host = platform_get_drvdata(pdev);
177 	struct hi3798cv200_priv *priv = host->priv;
178 
179 	clk_disable_unprepare(priv->drive_clk);
180 	clk_disable_unprepare(priv->sample_clk);
181 
182 	dw_mci_pltfm_remove(pdev);
183 
184 	return 0;
185 }
186 
187 static const struct of_device_id dw_mci_hi3798cv200_match[] = {
188 	{ .compatible = "hisilicon,hi3798cv200-dw-mshc", },
189 	{},
190 };
191 
192 MODULE_DEVICE_TABLE(of, dw_mci_hi3798cv200_match);
193 static struct platform_driver dw_mci_hi3798cv200_driver = {
194 	.probe = dw_mci_hi3798cv200_probe,
195 	.remove = dw_mci_hi3798cv200_remove,
196 	.driver = {
197 		.name = "dwmmc_hi3798cv200",
198 		.probe_type = PROBE_PREFER_ASYNCHRONOUS,
199 		.of_match_table = dw_mci_hi3798cv200_match,
200 	},
201 };
202 module_platform_driver(dw_mci_hi3798cv200_driver);
203 
204 MODULE_DESCRIPTION("HiSilicon Hi3798CV200 Specific DW-MSHC Driver Extension");
205 MODULE_LICENSE("GPL v2");
206 MODULE_ALIAS("platform:dwmmc_hi3798cv200");
207