1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Driver for Synopsys DesignWare Cores Mobile Storage Host Controller
4  *
5  * Copyright (C) 2018 Synaptics Incorporated
6  *
7  * Author: Jisheng Zhang <jszhang@kernel.org>
8  */
9 
10 #include <linux/clk.h>
11 #include <linux/dma-mapping.h>
12 #include <linux/kernel.h>
13 #include <linux/module.h>
14 #include <linux/of.h>
15 #include <linux/sizes.h>
16 
17 #include "sdhci-pltfm.h"
18 
19 #define BOUNDARY_OK(addr, len) \
20 	((addr | (SZ_128M - 1)) == ((addr + len - 1) | (SZ_128M - 1)))
21 
22 struct dwcmshc_priv {
23 	struct clk	*bus_clk;
24 };
25 
26 /*
27  * If DMA addr spans 128MB boundary, we split the DMA transfer into two
28  * so that each DMA transfer doesn't exceed the boundary.
29  */
30 static void dwcmshc_adma_write_desc(struct sdhci_host *host, void **desc,
31 				    dma_addr_t addr, int len, unsigned int cmd)
32 {
33 	int tmplen, offset;
34 
35 	if (likely(!len || BOUNDARY_OK(addr, len))) {
36 		sdhci_adma_write_desc(host, desc, addr, len, cmd);
37 		return;
38 	}
39 
40 	offset = addr & (SZ_128M - 1);
41 	tmplen = SZ_128M - offset;
42 	sdhci_adma_write_desc(host, desc, addr, tmplen, cmd);
43 
44 	addr += tmplen;
45 	len -= tmplen;
46 	sdhci_adma_write_desc(host, desc, addr, len, cmd);
47 }
48 
49 static const struct sdhci_ops sdhci_dwcmshc_ops = {
50 	.set_clock		= sdhci_set_clock,
51 	.set_bus_width		= sdhci_set_bus_width,
52 	.set_uhs_signaling	= sdhci_set_uhs_signaling,
53 	.get_max_clock		= sdhci_pltfm_clk_get_max_clock,
54 	.reset			= sdhci_reset,
55 	.adma_write_desc	= dwcmshc_adma_write_desc,
56 };
57 
58 static const struct sdhci_pltfm_data sdhci_dwcmshc_pdata = {
59 	.ops = &sdhci_dwcmshc_ops,
60 	.quirks = SDHCI_QUIRK_CAP_CLOCK_BASE_BROKEN,
61 };
62 
63 static int dwcmshc_probe(struct platform_device *pdev)
64 {
65 	struct sdhci_pltfm_host *pltfm_host;
66 	struct sdhci_host *host;
67 	struct dwcmshc_priv *priv;
68 	int err;
69 	u32 extra;
70 
71 	host = sdhci_pltfm_init(pdev, &sdhci_dwcmshc_pdata,
72 				sizeof(struct dwcmshc_priv));
73 	if (IS_ERR(host))
74 		return PTR_ERR(host);
75 
76 	/*
77 	 * extra adma table cnt for cross 128M boundary handling.
78 	 */
79 	extra = DIV_ROUND_UP_ULL(dma_get_required_mask(&pdev->dev), SZ_128M);
80 	if (extra > SDHCI_MAX_SEGS)
81 		extra = SDHCI_MAX_SEGS;
82 	host->adma_table_cnt += extra;
83 
84 	pltfm_host = sdhci_priv(host);
85 	priv = sdhci_pltfm_priv(pltfm_host);
86 
87 	pltfm_host->clk = devm_clk_get(&pdev->dev, "core");
88 	if (IS_ERR(pltfm_host->clk)) {
89 		err = PTR_ERR(pltfm_host->clk);
90 		dev_err(&pdev->dev, "failed to get core clk: %d\n", err);
91 		goto free_pltfm;
92 	}
93 	err = clk_prepare_enable(pltfm_host->clk);
94 	if (err)
95 		goto free_pltfm;
96 
97 	priv->bus_clk = devm_clk_get(&pdev->dev, "bus");
98 	if (!IS_ERR(priv->bus_clk))
99 		clk_prepare_enable(priv->bus_clk);
100 
101 	err = mmc_of_parse(host->mmc);
102 	if (err)
103 		goto err_clk;
104 
105 	sdhci_get_of_property(pdev);
106 
107 	err = sdhci_add_host(host);
108 	if (err)
109 		goto err_clk;
110 
111 	return 0;
112 
113 err_clk:
114 	clk_disable_unprepare(pltfm_host->clk);
115 	clk_disable_unprepare(priv->bus_clk);
116 free_pltfm:
117 	sdhci_pltfm_free(pdev);
118 	return err;
119 }
120 
121 static int dwcmshc_remove(struct platform_device *pdev)
122 {
123 	struct sdhci_host *host = platform_get_drvdata(pdev);
124 	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
125 	struct dwcmshc_priv *priv = sdhci_pltfm_priv(pltfm_host);
126 
127 	sdhci_remove_host(host, 0);
128 
129 	clk_disable_unprepare(pltfm_host->clk);
130 	clk_disable_unprepare(priv->bus_clk);
131 
132 	sdhci_pltfm_free(pdev);
133 
134 	return 0;
135 }
136 
137 static const struct of_device_id sdhci_dwcmshc_dt_ids[] = {
138 	{ .compatible = "snps,dwcmshc-sdhci" },
139 	{}
140 };
141 MODULE_DEVICE_TABLE(of, sdhci_dwcmshc_dt_ids);
142 
143 static struct platform_driver sdhci_dwcmshc_driver = {
144 	.driver	= {
145 		.name	= "sdhci-dwcmshc",
146 		.of_match_table = sdhci_dwcmshc_dt_ids,
147 	},
148 	.probe	= dwcmshc_probe,
149 	.remove	= dwcmshc_remove,
150 };
151 module_platform_driver(sdhci_dwcmshc_driver);
152 
153 MODULE_DESCRIPTION("SDHCI platform driver for Synopsys DWC MSHC");
154 MODULE_AUTHOR("Jisheng Zhang <jszhang@kernel.org>");
155 MODULE_LICENSE("GPL v2");
156