1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright (C) 2023-2025 SpacemiT (Hangzhou) Technology Co. Ltd
4  * Copyright (c) 2025 Yixun Lan <dlan@gentoo.org>
5  */
6 
7 #include <linux/bitfield.h>
8 #include <linux/clk.h>
9 #include <linux/delay.h>
10 #include <linux/iopoll.h>
11 #include <linux/init.h>
12 #include <linux/mmc/card.h>
13 #include <linux/mmc/host.h>
14 #include <linux/mmc/mmc.h>
15 #include <linux/module.h>
16 #include <linux/of.h>
17 #include <linux/of_device.h>
18 #include <linux/platform_device.h>
19 
20 #include "sdhci.h"
21 #include "sdhci-pltfm.h"
22 
23 #define SDHC_MMC_CTRL_REG		0x114
24 #define  MISC_INT_EN			BIT(1)
25 #define  MISC_INT			BIT(2)
26 #define  ENHANCE_STROBE_EN		BIT(8)
27 #define  MMC_HS400			BIT(9)
28 #define  MMC_HS200			BIT(10)
29 #define  MMC_CARD_MODE			BIT(12)
30 
31 #define SDHC_TX_CFG_REG			0x11C
32 #define  TX_INT_CLK_SEL			BIT(30)
33 #define  TX_MUX_SEL			BIT(31)
34 
35 #define SDHC_PHY_CTRL_REG		0x160
36 #define  PHY_FUNC_EN			BIT(0)
37 #define  PHY_PLL_LOCK			BIT(1)
38 #define  HOST_LEGACY_MODE		BIT(31)
39 
40 #define SDHC_PHY_FUNC_REG		0x164
41 #define  PHY_TEST_EN			BIT(7)
42 #define  HS200_USE_RFIFO		BIT(15)
43 
44 #define SDHC_PHY_DLLCFG			0x168
45 #define  DLL_PREDLY_NUM			GENMASK(3, 2)
46 #define  DLL_FULLDLY_RANGE		GENMASK(5, 4)
47 #define  DLL_VREG_CTRL			GENMASK(7, 6)
48 #define  DLL_ENABLE			BIT(31)
49 
50 #define SDHC_PHY_DLLCFG1		0x16C
51 #define  DLL_REG1_CTRL			GENMASK(7, 0)
52 #define  DLL_REG2_CTRL			GENMASK(15, 8)
53 #define  DLL_REG3_CTRL			GENMASK(23, 16)
54 #define  DLL_REG4_CTRL			GENMASK(31, 24)
55 
56 #define SDHC_PHY_DLLSTS			0x170
57 #define  DLL_LOCK_STATE			BIT(0)
58 
59 #define SDHC_PHY_PADCFG_REG		0x178
60 #define  PHY_DRIVE_SEL			GENMASK(2, 0)
61 #define  RX_BIAS_CTRL			BIT(5)
62 
63 struct spacemit_sdhci_host {
64 	struct clk *clk_core;
65 	struct clk *clk_io;
66 };
67 
68 /* All helper functions will update clr/set while preserve rest bits */
69 static inline void spacemit_sdhci_setbits(struct sdhci_host *host, u32 val, int reg)
70 {
71 	sdhci_writel(host, sdhci_readl(host, reg) | val, reg);
72 }
73 
74 static inline void spacemit_sdhci_clrbits(struct sdhci_host *host, u32 val, int reg)
75 {
76 	sdhci_writel(host, sdhci_readl(host, reg) & ~val, reg);
77 }
78 
79 static inline void spacemit_sdhci_clrsetbits(struct sdhci_host *host, u32 clr, u32 set, int reg)
80 {
81 	u32 val = sdhci_readl(host, reg);
82 
83 	val = (val & ~clr) | set;
84 	sdhci_writel(host, val, reg);
85 }
86 
87 static void spacemit_sdhci_reset(struct sdhci_host *host, u8 mask)
88 {
89 	sdhci_reset(host, mask);
90 
91 	if (mask != SDHCI_RESET_ALL)
92 		return;
93 
94 	spacemit_sdhci_setbits(host, PHY_FUNC_EN | PHY_PLL_LOCK, SDHC_PHY_CTRL_REG);
95 
96 	spacemit_sdhci_clrsetbits(host, PHY_DRIVE_SEL,
97 				  RX_BIAS_CTRL | FIELD_PREP(PHY_DRIVE_SEL, 4),
98 				  SDHC_PHY_PADCFG_REG);
99 
100 	if (!(host->mmc->caps2 & MMC_CAP2_NO_MMC))
101 		spacemit_sdhci_setbits(host, MMC_CARD_MODE, SDHC_MMC_CTRL_REG);
102 }
103 
104 static void spacemit_sdhci_set_uhs_signaling(struct sdhci_host *host, unsigned int timing)
105 {
106 	if (timing == MMC_TIMING_MMC_HS200)
107 		spacemit_sdhci_setbits(host, MMC_HS200, SDHC_MMC_CTRL_REG);
108 
109 	if (timing == MMC_TIMING_MMC_HS400)
110 		spacemit_sdhci_setbits(host, MMC_HS400, SDHC_MMC_CTRL_REG);
111 
112 	sdhci_set_uhs_signaling(host, timing);
113 
114 	if (!(host->mmc->caps2 & MMC_CAP2_NO_SDIO))
115 		spacemit_sdhci_setbits(host, SDHCI_CTRL_VDD_180, SDHCI_HOST_CONTROL2);
116 }
117 
118 static void spacemit_sdhci_set_clock(struct sdhci_host *host, unsigned int clock)
119 {
120 	struct mmc_host *mmc = host->mmc;
121 
122 	if (mmc->ios.timing <= MMC_TIMING_UHS_SDR50)
123 		spacemit_sdhci_setbits(host, TX_INT_CLK_SEL, SDHC_TX_CFG_REG);
124 	else
125 		spacemit_sdhci_clrbits(host, TX_INT_CLK_SEL, SDHC_TX_CFG_REG);
126 
127 	sdhci_set_clock(host, clock);
128 };
129 
130 static void spacemit_sdhci_phy_dll_init(struct sdhci_host *host)
131 {
132 	u32 state;
133 	int ret;
134 
135 	spacemit_sdhci_clrsetbits(host, DLL_PREDLY_NUM | DLL_FULLDLY_RANGE | DLL_VREG_CTRL,
136 				  FIELD_PREP(DLL_PREDLY_NUM, 1) |
137 				  FIELD_PREP(DLL_FULLDLY_RANGE, 1) |
138 				  FIELD_PREP(DLL_VREG_CTRL, 1),
139 				  SDHC_PHY_DLLCFG);
140 
141 	spacemit_sdhci_clrsetbits(host, DLL_REG1_CTRL,
142 				  FIELD_PREP(DLL_REG1_CTRL, 0x92),
143 				  SDHC_PHY_DLLCFG1);
144 
145 	spacemit_sdhci_setbits(host, DLL_ENABLE, SDHC_PHY_DLLCFG);
146 
147 	ret = readl_poll_timeout(host->ioaddr + SDHC_PHY_DLLSTS, state,
148 				 state & DLL_LOCK_STATE, 2, 100);
149 	if (ret == -ETIMEDOUT)
150 		dev_warn(mmc_dev(host->mmc), "fail to lock phy dll in 100us!\n");
151 }
152 
153 static void spacemit_sdhci_hs400_enhanced_strobe(struct mmc_host *mmc, struct mmc_ios *ios)
154 {
155 	struct sdhci_host *host = mmc_priv(mmc);
156 
157 	if (!ios->enhanced_strobe) {
158 		spacemit_sdhci_clrbits(host, ENHANCE_STROBE_EN, SDHC_MMC_CTRL_REG);
159 		return;
160 	}
161 
162 	spacemit_sdhci_setbits(host, ENHANCE_STROBE_EN, SDHC_MMC_CTRL_REG);
163 	spacemit_sdhci_phy_dll_init(host);
164 }
165 
166 static unsigned int spacemit_sdhci_clk_get_max_clock(struct sdhci_host *host)
167 {
168 	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
169 
170 	return clk_get_rate(pltfm_host->clk);
171 }
172 
173 static int spacemit_sdhci_pre_select_hs400(struct mmc_host *mmc)
174 {
175 	struct sdhci_host *host = mmc_priv(mmc);
176 
177 	spacemit_sdhci_setbits(host, MMC_HS400, SDHC_MMC_CTRL_REG);
178 	host->mmc->caps |= MMC_CAP_WAIT_WHILE_BUSY;
179 
180 	return 0;
181 }
182 
183 static void spacemit_sdhci_post_select_hs400(struct mmc_host *mmc)
184 {
185 	struct sdhci_host *host = mmc_priv(mmc);
186 
187 	spacemit_sdhci_phy_dll_init(host);
188 	host->mmc->caps &= ~MMC_CAP_WAIT_WHILE_BUSY;
189 }
190 
191 static void spacemit_sdhci_pre_hs400_to_hs200(struct mmc_host *mmc)
192 {
193 	struct sdhci_host *host = mmc_priv(mmc);
194 
195 	spacemit_sdhci_clrbits(host, PHY_FUNC_EN | PHY_PLL_LOCK, SDHC_PHY_CTRL_REG);
196 	spacemit_sdhci_clrbits(host, MMC_HS400 | MMC_HS200 | ENHANCE_STROBE_EN, SDHC_MMC_CTRL_REG);
197 	spacemit_sdhci_clrbits(host, HS200_USE_RFIFO, SDHC_PHY_FUNC_REG);
198 
199 	udelay(5);
200 
201 	spacemit_sdhci_setbits(host, PHY_FUNC_EN | PHY_PLL_LOCK, SDHC_PHY_CTRL_REG);
202 }
203 
204 static inline int spacemit_sdhci_get_clocks(struct device *dev,
205 					    struct sdhci_pltfm_host *pltfm_host)
206 {
207 	struct spacemit_sdhci_host *sdhst = sdhci_pltfm_priv(pltfm_host);
208 
209 	sdhst->clk_core = devm_clk_get_enabled(dev, "core");
210 	if (IS_ERR(sdhst->clk_core))
211 		return -EINVAL;
212 
213 	sdhst->clk_io = devm_clk_get_enabled(dev, "io");
214 	if (IS_ERR(sdhst->clk_io))
215 		return -EINVAL;
216 
217 	pltfm_host->clk = sdhst->clk_io;
218 
219 	return 0;
220 }
221 
222 static const struct sdhci_ops spacemit_sdhci_ops = {
223 	.get_max_clock		= spacemit_sdhci_clk_get_max_clock,
224 	.reset			= spacemit_sdhci_reset,
225 	.set_bus_width		= sdhci_set_bus_width,
226 	.set_clock		= spacemit_sdhci_set_clock,
227 	.set_uhs_signaling	= spacemit_sdhci_set_uhs_signaling,
228 };
229 
230 static const struct sdhci_pltfm_data spacemit_sdhci_k1_pdata = {
231 	.ops = &spacemit_sdhci_ops,
232 	.quirks = SDHCI_QUIRK_DATA_TIMEOUT_USES_SDCLK |
233 		  SDHCI_QUIRK_NO_ENDATTR_IN_NOPDESC |
234 		  SDHCI_QUIRK_32BIT_ADMA_SIZE |
235 		  SDHCI_QUIRK_CAP_CLOCK_BASE_BROKEN |
236 		  SDHCI_QUIRK_BROKEN_CARD_DETECTION |
237 		  SDHCI_QUIRK_BROKEN_TIMEOUT_VAL,
238 	.quirks2 = SDHCI_QUIRK2_BROKEN_64_BIT_DMA |
239 		   SDHCI_QUIRK2_PRESET_VALUE_BROKEN,
240 };
241 
242 static const struct of_device_id spacemit_sdhci_of_match[] = {
243 	{ .compatible = "spacemit,k1-sdhci" },
244 	{ /* sentinel */ }
245 };
246 MODULE_DEVICE_TABLE(of, spacemit_sdhci_of_match);
247 
248 static int spacemit_sdhci_probe(struct platform_device *pdev)
249 {
250 	struct device *dev = &pdev->dev;
251 	struct spacemit_sdhci_host *sdhst;
252 	struct sdhci_pltfm_host *pltfm_host;
253 	struct sdhci_host *host;
254 	struct mmc_host_ops *mops;
255 	int ret;
256 
257 	host = sdhci_pltfm_init(pdev, &spacemit_sdhci_k1_pdata, sizeof(*sdhst));
258 	if (IS_ERR(host))
259 		return PTR_ERR(host);
260 
261 	pltfm_host = sdhci_priv(host);
262 
263 	ret = mmc_of_parse(host->mmc);
264 	if (ret)
265 		goto err_pltfm;
266 
267 	sdhci_get_of_property(pdev);
268 
269 	if (!(host->mmc->caps2 & MMC_CAP2_NO_MMC)) {
270 		mops = &host->mmc_host_ops;
271 		mops->hs400_prepare_ddr	= spacemit_sdhci_pre_select_hs400;
272 		mops->hs400_complete	= spacemit_sdhci_post_select_hs400;
273 		mops->hs400_downgrade	= spacemit_sdhci_pre_hs400_to_hs200;
274 		mops->hs400_enhanced_strobe = spacemit_sdhci_hs400_enhanced_strobe;
275 	}
276 
277 	host->mmc->caps |= MMC_CAP_NEED_RSP_BUSY;
278 
279 	if (spacemit_sdhci_get_clocks(dev, pltfm_host))
280 		goto err_pltfm;
281 
282 	ret = sdhci_add_host(host);
283 	if (ret)
284 		goto err_pltfm;
285 
286 	return 0;
287 
288 err_pltfm:
289 	sdhci_pltfm_free(pdev);
290 	return ret;
291 }
292 
293 static struct platform_driver spacemit_sdhci_driver = {
294 	.driver		= {
295 		.name	= "sdhci-spacemit",
296 		.of_match_table = spacemit_sdhci_of_match,
297 	},
298 	.probe		= spacemit_sdhci_probe,
299 	.remove		= sdhci_pltfm_remove,
300 };
301 module_platform_driver(spacemit_sdhci_driver);
302 
303 MODULE_DESCRIPTION("SpacemiT SDHCI platform driver");
304 MODULE_LICENSE("GPL");
305