1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * ZX Specific Extensions for Synopsys DW Multimedia Card Interface driver
4 *
5 * Copyright (C) 2016, Linaro Ltd.
6 * Copyright (C) 2016, ZTE Corp.
7 */
8
9#include <linux/clk.h>
10#include <linux/mfd/syscon.h>
11#include <linux/mmc/host.h>
12#include <linux/mmc/mmc.h>
13#include <linux/module.h>
14#include <linux/of.h>
15#include <linux/platform_device.h>
16#include <linux/pm_runtime.h>
17#include <linux/regmap.h>
18#include <linux/slab.h>
19
20#include "dw_mmc.h"
21#include "dw_mmc-pltfm.h"
22#include "dw_mmc-zx.h"
23
24struct dw_mci_zx_priv_data {
25	struct regmap	*sysc_base;
26};
27
28enum delay_type {
29	DELAY_TYPE_READ,	/* read dqs delay */
30	DELAY_TYPE_CLK,		/* clk sample delay */
31};
32
33static int dw_mci_zx_emmc_set_delay(struct dw_mci *host, unsigned int delay,
34				    enum delay_type dflag)
35{
36	struct dw_mci_zx_priv_data *priv = host->priv;
37	struct regmap *sysc_base = priv->sysc_base;
38	unsigned int clksel;
39	unsigned int loop = 1000;
40	int ret;
41
42	if (!sysc_base)
43		return -EINVAL;
44
45	ret = regmap_update_bits(sysc_base, LB_AON_EMMC_CFG_REG0,
46				 PARA_HALF_CLK_MODE | PARA_DLL_BYPASS_MODE |
47				 PARA_PHASE_DET_SEL_MASK |
48				 PARA_DLL_LOCK_NUM_MASK |
49				 DLL_REG_SET | PARA_DLL_START_MASK,
50				 PARA_DLL_START(4) | PARA_DLL_LOCK_NUM(4));
51	if (ret)
52		return ret;
53
54	ret = regmap_read(sysc_base, LB_AON_EMMC_CFG_REG1, &clksel);
55	if (ret)
56		return ret;
57
58	if (dflag == DELAY_TYPE_CLK) {
59		clksel &= ~CLK_SAMP_DELAY_MASK;
60		clksel |= CLK_SAMP_DELAY(delay);
61	} else {
62		clksel &= ~READ_DQS_DELAY_MASK;
63		clksel |= READ_DQS_DELAY(delay);
64	}
65
66	regmap_write(sysc_base, LB_AON_EMMC_CFG_REG1, clksel);
67	regmap_update_bits(sysc_base, LB_AON_EMMC_CFG_REG0,
68			   PARA_DLL_START_MASK | PARA_DLL_LOCK_NUM_MASK |
69			   DLL_REG_SET,
70			   PARA_DLL_START(4) | PARA_DLL_LOCK_NUM(4) |
71			   DLL_REG_SET);
72
73	do {
74		ret = regmap_read(sysc_base, LB_AON_EMMC_CFG_REG2, &clksel);
75		if (ret)
76			return ret;
77
78	} while (--loop && !(clksel & ZX_DLL_LOCKED));
79
80	if (!loop) {
81		dev_err(host->dev, "Error: %s dll lock fail\n", __func__);
82		return -EIO;
83	}
84
85	return 0;
86}
87
88static int dw_mci_zx_emmc_execute_tuning(struct dw_mci_slot *slot, u32 opcode)
89{
90	struct dw_mci *host = slot->host;
91	struct mmc_host *mmc = slot->mmc;
92	int ret, len = 0, start = 0, end = 0, delay, best = 0;
93
94	for (delay = 1; delay < 128; delay++) {
95		ret = dw_mci_zx_emmc_set_delay(host, delay, DELAY_TYPE_CLK);
96		if (!ret && mmc_send_tuning(mmc, opcode, NULL)) {
97			if (start >= 0) {
98				end = delay - 1;
99				/* check and update longest good range */
100				if ((end - start) > len) {
101					best = (start + end) >> 1;
102					len = end - start;
103				}
104			}
105			start = -1;
106			end = 0;
107			continue;
108		}
109		if (start < 0)
110			start = delay;
111	}
112
113	if (start >= 0) {
114		end = delay - 1;
115		if ((end - start) > len) {
116			best = (start + end) >> 1;
117			len = end - start;
118		}
119	}
120	if (best < 0)
121		return -EIO;
122
123	dev_info(host->dev, "%s best range: start %d end %d\n", __func__,
124		 start, end);
125	return dw_mci_zx_emmc_set_delay(host, best, DELAY_TYPE_CLK);
126}
127
128static int dw_mci_zx_prepare_hs400_tuning(struct dw_mci *host,
129					  struct mmc_ios *ios)
130{
131	int ret;
132
133	/* config phase shift as 90 degree */
134	ret = dw_mci_zx_emmc_set_delay(host, 32, DELAY_TYPE_READ);
135	if (ret < 0)
136		return -EIO;
137
138	return 0;
139}
140
141static int dw_mci_zx_execute_tuning(struct dw_mci_slot *slot, u32 opcode)
142{
143	struct dw_mci *host = slot->host;
144
145	if (host->verid == 0x290a) /* only for emmc */
146		return dw_mci_zx_emmc_execute_tuning(slot, opcode);
147	/* TODO: Add 0x210a dedicated tuning for sd/sdio */
148
149	return 0;
150}
151
152static int dw_mci_zx_parse_dt(struct dw_mci *host)
153{
154	struct device_node *np = host->dev->of_node;
155	struct device_node *node;
156	struct dw_mci_zx_priv_data *priv;
157	struct regmap *sysc_base;
158
159	/* syscon is needed only by emmc */
160	node = of_parse_phandle(np, "zte,aon-syscon", 0);
161	if (node) {
162		sysc_base = syscon_node_to_regmap(node);
163		of_node_put(node);
164
165		if (IS_ERR(sysc_base))
166			return dev_err_probe(host->dev, PTR_ERR(sysc_base),
167					     "Can't get syscon\n");
168	} else {
169		return 0;
170	}
171
172	priv = devm_kzalloc(host->dev, sizeof(*priv), GFP_KERNEL);
173	if (!priv)
174		return -ENOMEM;
175	priv->sysc_base = sysc_base;
176	host->priv = priv;
177
178	return 0;
179}
180
181static unsigned long zx_dwmmc_caps[3] = {
182	MMC_CAP_CMD23,
183	MMC_CAP_CMD23,
184	MMC_CAP_CMD23,
185};
186
187static const struct dw_mci_drv_data zx_drv_data = {
188	.caps			= zx_dwmmc_caps,
189	.num_caps		= ARRAY_SIZE(zx_dwmmc_caps),
190	.execute_tuning		= dw_mci_zx_execute_tuning,
191	.prepare_hs400_tuning	= dw_mci_zx_prepare_hs400_tuning,
192	.parse_dt               = dw_mci_zx_parse_dt,
193};
194
195static const struct of_device_id dw_mci_zx_match[] = {
196	{ .compatible = "zte,zx296718-dw-mshc", .data = &zx_drv_data},
197	{},
198};
199MODULE_DEVICE_TABLE(of, dw_mci_zx_match);
200
201static int dw_mci_zx_probe(struct platform_device *pdev)
202{
203	const struct dw_mci_drv_data *drv_data;
204	const struct of_device_id *match;
205
206	match = of_match_node(dw_mci_zx_match, pdev->dev.of_node);
207	drv_data = match->data;
208
209	return dw_mci_pltfm_register(pdev, drv_data);
210}
211
212static const struct dev_pm_ops dw_mci_zx_dev_pm_ops = {
213	SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
214				pm_runtime_force_resume)
215	SET_RUNTIME_PM_OPS(dw_mci_runtime_suspend,
216			   dw_mci_runtime_resume,
217			   NULL)
218};
219
220static struct platform_driver dw_mci_zx_pltfm_driver = {
221	.probe		= dw_mci_zx_probe,
222	.remove		= dw_mci_pltfm_remove,
223	.driver		= {
224		.name		= "dwmmc_zx",
225		.probe_type	= PROBE_PREFER_ASYNCHRONOUS,
226		.of_match_table	= dw_mci_zx_match,
227		.pm		= &dw_mci_zx_dev_pm_ops,
228	},
229};
230
231module_platform_driver(dw_mci_zx_pltfm_driver);
232
233MODULE_DESCRIPTION("ZTE emmc/sd driver");
234MODULE_LICENSE("GPL v2");
235