1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * SDHCI support for SiRF primaII and marco SoCs
4 *
5 * Copyright (c) 2011 Cambridge Silicon Radio Limited, a CSR plc group company.
6 */
7
8 #include <linux/delay.h>
9 #include <linux/device.h>
10 #include <linux/mmc/host.h>
11 #include <linux/module.h>
12 #include <linux/of.h>
13 #include <linux/mmc/slot-gpio.h>
14 #include "sdhci-pltfm.h"
15
16 #define SDHCI_CLK_DELAY_SETTING 0x4C
17 #define SDHCI_SIRF_8BITBUS BIT(3)
18 #define SIRF_TUNING_COUNT 16384
19
sdhci_sirf_set_bus_width(struct sdhci_host * host,int width)20 static void sdhci_sirf_set_bus_width(struct sdhci_host *host, int width)
21 {
22 u8 ctrl;
23
24 ctrl = sdhci_readb(host, SDHCI_HOST_CONTROL);
25 ctrl &= ~(SDHCI_CTRL_4BITBUS | SDHCI_SIRF_8BITBUS);
26
27 /*
28 * CSR atlas7 and prima2 SD host version is not 3.0
29 * 8bit-width enable bit of CSR SD hosts is 3,
30 * while stardard hosts use bit 5
31 */
32 if (width == MMC_BUS_WIDTH_8)
33 ctrl |= SDHCI_SIRF_8BITBUS;
34 else if (width == MMC_BUS_WIDTH_4)
35 ctrl |= SDHCI_CTRL_4BITBUS;
36
37 sdhci_writeb(host, ctrl, SDHCI_HOST_CONTROL);
38 }
39
sdhci_sirf_readl_le(struct sdhci_host * host,int reg)40 static u32 sdhci_sirf_readl_le(struct sdhci_host *host, int reg)
41 {
42 u32 val = readl(host->ioaddr + reg);
43
44 if (unlikely((reg == SDHCI_CAPABILITIES_1) &&
45 (host->mmc->caps & MMC_CAP_UHS_SDR50))) {
46 /* fake CAP_1 register */
47 val = SDHCI_SUPPORT_DDR50 |
48 SDHCI_SUPPORT_SDR50 | SDHCI_USE_SDR50_TUNING;
49 }
50
51 if (unlikely(reg == SDHCI_SLOT_INT_STATUS)) {
52 u32 prss = val;
53 /* fake chips as V3.0 host conreoller */
54 prss &= ~(0xFF << 16);
55 val = prss | (SDHCI_SPEC_300 << 16);
56 }
57 return val;
58 }
59
sdhci_sirf_readw_le(struct sdhci_host * host,int reg)60 static u16 sdhci_sirf_readw_le(struct sdhci_host *host, int reg)
61 {
62 u16 ret = 0;
63
64 ret = readw(host->ioaddr + reg);
65
66 if (unlikely(reg == SDHCI_HOST_VERSION)) {
67 ret = readw(host->ioaddr + SDHCI_HOST_VERSION);
68 ret |= SDHCI_SPEC_300;
69 }
70
71 return ret;
72 }
73
sdhci_sirf_execute_tuning(struct sdhci_host * host,u32 opcode)74 static int sdhci_sirf_execute_tuning(struct sdhci_host *host, u32 opcode)
75 {
76 int tuning_seq_cnt = 3;
77 int phase;
78 u8 tuned_phase_cnt = 0;
79 int rc = 0, longest_range = 0;
80 int start = -1, end = 0, tuning_value = -1, range = 0;
81 u16 clock_setting;
82 struct mmc_host *mmc = host->mmc;
83
84 clock_setting = sdhci_readw(host, SDHCI_CLK_DELAY_SETTING);
85 clock_setting &= ~0x3fff;
86
87 retry:
88 phase = 0;
89 tuned_phase_cnt = 0;
90 do {
91 sdhci_writel(host,
92 clock_setting | phase,
93 SDHCI_CLK_DELAY_SETTING);
94
95 if (!mmc_send_tuning(mmc, opcode, NULL)) {
96 /* Tuning is successful at this tuning point */
97 tuned_phase_cnt++;
98 dev_dbg(mmc_dev(mmc), "%s: Found good phase = %d\n",
99 mmc_hostname(mmc), phase);
100 if (start == -1)
101 start = phase;
102 end = phase;
103 range++;
104 if (phase == (SIRF_TUNING_COUNT - 1)
105 && range > longest_range)
106 tuning_value = (start + end) / 2;
107 } else {
108 dev_dbg(mmc_dev(mmc), "%s: Found bad phase = %d\n",
109 mmc_hostname(mmc), phase);
110 if (range > longest_range) {
111 tuning_value = (start + end) / 2;
112 longest_range = range;
113 }
114 start = -1;
115 end = range = 0;
116 }
117 } while (++phase < SIRF_TUNING_COUNT);
118
119 if (tuned_phase_cnt && tuning_value > 0) {
120 /*
121 * Finally set the selected phase in delay
122 * line hw block.
123 */
124 phase = tuning_value;
125 sdhci_writel(host,
126 clock_setting | phase,
127 SDHCI_CLK_DELAY_SETTING);
128
129 dev_dbg(mmc_dev(mmc), "%s: Setting the tuning phase to %d\n",
130 mmc_hostname(mmc), phase);
131 } else {
132 if (--tuning_seq_cnt)
133 goto retry;
134 /* Tuning failed */
135 dev_dbg(mmc_dev(mmc), "%s: No tuning point found\n",
136 mmc_hostname(mmc));
137 rc = -EIO;
138 }
139
140 return rc;
141 }
142
143 static const struct sdhci_ops sdhci_sirf_ops = {
144 .read_l = sdhci_sirf_readl_le,
145 .read_w = sdhci_sirf_readw_le,
146 .platform_execute_tuning = sdhci_sirf_execute_tuning,
147 .set_clock = sdhci_set_clock,
148 .get_max_clock = sdhci_pltfm_clk_get_max_clock,
149 .set_bus_width = sdhci_sirf_set_bus_width,
150 .reset = sdhci_reset,
151 .set_uhs_signaling = sdhci_set_uhs_signaling,
152 };
153
154 static const struct sdhci_pltfm_data sdhci_sirf_pdata = {
155 .ops = &sdhci_sirf_ops,
156 .quirks = SDHCI_QUIRK_BROKEN_TIMEOUT_VAL |
157 SDHCI_QUIRK_DATA_TIMEOUT_USES_SDCLK |
158 SDHCI_QUIRK_CAP_CLOCK_BASE_BROKEN |
159 SDHCI_QUIRK_RESET_CMD_DATA_ON_IOS,
160 .quirks2 = SDHCI_QUIRK2_PRESET_VALUE_BROKEN,
161 };
162
sdhci_sirf_probe(struct platform_device * pdev)163 static int sdhci_sirf_probe(struct platform_device *pdev)
164 {
165 struct sdhci_host *host;
166 struct sdhci_pltfm_host *pltfm_host;
167 struct clk *clk;
168 int ret;
169
170 clk = devm_clk_get(&pdev->dev, NULL);
171 if (IS_ERR(clk)) {
172 dev_err(&pdev->dev, "unable to get clock");
173 return PTR_ERR(clk);
174 }
175
176 host = sdhci_pltfm_init(pdev, &sdhci_sirf_pdata, 0);
177 if (IS_ERR(host))
178 return PTR_ERR(host);
179
180 pltfm_host = sdhci_priv(host);
181 pltfm_host->clk = clk;
182
183 sdhci_get_of_property(pdev);
184
185 ret = clk_prepare_enable(pltfm_host->clk);
186 if (ret)
187 goto err_clk_prepare;
188
189 ret = sdhci_add_host(host);
190 if (ret)
191 goto err_sdhci_add;
192
193 /*
194 * We must request the IRQ after sdhci_add_host(), as the tasklet only
195 * gets setup in sdhci_add_host() and we oops.
196 */
197 ret = mmc_gpiod_request_cd(host->mmc, "cd", 0, false, 0, NULL);
198 if (ret == -EPROBE_DEFER)
199 goto err_request_cd;
200 if (!ret)
201 mmc_gpiod_request_cd_irq(host->mmc);
202
203 return 0;
204
205 err_request_cd:
206 sdhci_remove_host(host, 0);
207 err_sdhci_add:
208 clk_disable_unprepare(pltfm_host->clk);
209 err_clk_prepare:
210 sdhci_pltfm_free(pdev);
211 return ret;
212 }
213
214 static const struct of_device_id sdhci_sirf_of_match[] = {
215 { .compatible = "sirf,prima2-sdhc" },
216 { }
217 };
218 MODULE_DEVICE_TABLE(of, sdhci_sirf_of_match);
219
220 static struct platform_driver sdhci_sirf_driver = {
221 .driver = {
222 .name = "sdhci-sirf",
223 .of_match_table = sdhci_sirf_of_match,
224 .pm = &sdhci_pltfm_pmops,
225 },
226 .probe = sdhci_sirf_probe,
227 .remove = sdhci_pltfm_unregister,
228 };
229
230 module_platform_driver(sdhci_sirf_driver);
231
232 MODULE_DESCRIPTION("SDHCI driver for SiRFprimaII/SiRFmarco");
233 MODULE_AUTHOR("Barry Song <21cnbao@gmail.com>");
234 MODULE_LICENSE("GPL v2");
235