xref: /openbmc/u-boot/drivers/mmc/exynos_dw_mmc.c (revision 70ad375e)
1 /*
2  * (C) Copyright 2012 SAMSUNG Electronics
3  * Jaehoon Chung <jh80.chung@samsung.com>
4  *
5  * SPDX-License-Identifier:	GPL-2.0+
6  */
7 
8 #include <common.h>
9 #include <dwmmc.h>
10 #include <fdtdec.h>
11 #include <libfdt.h>
12 #include <malloc.h>
13 #include <asm/arch/dwmmc.h>
14 #include <asm/arch/clk.h>
15 #include <asm/arch/pinmux.h>
16 
17 #define	DWMMC_MAX_CH_NUM		4
18 #define	DWMMC_MAX_FREQ			52000000
19 #define	DWMMC_MIN_FREQ			400000
20 #define	DWMMC_MMC0_CLKSEL_VAL		0x03030001
21 #define	DWMMC_MMC2_CLKSEL_VAL		0x03020001
22 
23 /*
24  * Function used as callback function to initialise the
25  * CLKSEL register for every mmc channel.
26  */
27 static void exynos_dwmci_clksel(struct dwmci_host *host)
28 {
29 	dwmci_writel(host, DWMCI_CLKSEL, host->clksel_val);
30 }
31 
32 unsigned int exynos_dwmci_get_clk(struct dwmci_host *host)
33 {
34 	unsigned long sclk;
35 	int8_t clk_div;
36 
37 	/*
38 	 * Since SDCLKIN is divided inside controller by the DIVRATIO
39 	 * value set in the CLKSEL register, we need to use the same output
40 	 * clock value to calculate the CLKDIV value.
41 	 * as per user manual:cclk_in = SDCLKIN / (DIVRATIO + 1)
42 	 */
43 	clk_div = ((dwmci_readl(host, DWMCI_CLKSEL) >> DWMCI_DIVRATIO_BIT)
44 			& DWMCI_DIVRATIO_MASK) + 1;
45 	sclk = get_mmc_clk(host->dev_index);
46 
47 	return sclk / clk_div;
48 }
49 
50 static void exynos_dwmci_board_init(struct dwmci_host *host)
51 {
52 	if (host->quirks & DWMCI_QUIRK_DISABLE_SMU) {
53 		dwmci_writel(host, EMMCP_MPSBEGIN0, 0);
54 		dwmci_writel(host, EMMCP_SEND0, 0);
55 		dwmci_writel(host, EMMCP_CTRL0,
56 			     MPSCTRL_SECURE_READ_BIT |
57 			     MPSCTRL_SECURE_WRITE_BIT |
58 			     MPSCTRL_NON_SECURE_READ_BIT |
59 			     MPSCTRL_NON_SECURE_WRITE_BIT | MPSCTRL_VALID);
60 	}
61 }
62 
63 /*
64  * This function adds the mmc channel to be registered with mmc core.
65  * index -	mmc channel number.
66  * regbase -	register base address of mmc channel specified in 'index'.
67  * bus_width -	operating bus width of mmc channel specified in 'index'.
68  * clksel -	value to be written into CLKSEL register in case of FDT.
69  *		NULL in case od non-FDT.
70  */
71 int exynos_dwmci_add_port(int index, u32 regbase, int bus_width, u32 clksel)
72 {
73 	struct dwmci_host *host = NULL;
74 	unsigned int div;
75 	unsigned long freq, sclk;
76 	host = malloc(sizeof(struct dwmci_host));
77 	if (!host) {
78 		printf("dwmci_host malloc fail!\n");
79 		return 1;
80 	}
81 	/* request mmc clock vlaue of 52MHz.  */
82 	freq = 52000000;
83 	sclk = get_mmc_clk(index);
84 	div = DIV_ROUND_UP(sclk, freq);
85 	/* set the clock divisor for mmc */
86 	set_mmc_clk(index, div);
87 
88 	host->name = "EXYNOS DWMMC";
89 	host->ioaddr = (void *)regbase;
90 	host->buswidth = bus_width;
91 #ifdef CONFIG_EXYNOS5420
92 	host->quirks = DWMCI_QUIRK_DISABLE_SMU;
93 #endif
94 	host->board_init = exynos_dwmci_board_init;
95 
96 	if (clksel) {
97 		host->clksel_val = clksel;
98 	} else {
99 		if (0 == index)
100 			host->clksel_val = DWMMC_MMC0_CLKSEL_VAL;
101 		if (2 == index)
102 			host->clksel_val = DWMMC_MMC2_CLKSEL_VAL;
103 	}
104 
105 	host->clksel = exynos_dwmci_clksel;
106 	host->dev_index = index;
107 	host->get_mmc_clk = exynos_dwmci_get_clk;
108 	/* Add the mmc channel to be registered with mmc core */
109 	if (add_dwmci(host, DWMMC_MAX_FREQ, DWMMC_MIN_FREQ)) {
110 		debug("dwmmc%d registration failed\n", index);
111 		return -1;
112 	}
113 	return 0;
114 }
115 
116 #ifdef CONFIG_OF_CONTROL
117 int exynos_dwmmc_init(const void *blob)
118 {
119 	int index, bus_width;
120 	int node_list[DWMMC_MAX_CH_NUM];
121 	int err = 0, dev_id, flag, count, i;
122 	u32 clksel_val, base, timing[3];
123 
124 	count = fdtdec_find_aliases_for_id(blob, "mmc",
125 				COMPAT_SAMSUNG_EXYNOS5_DWMMC, node_list,
126 				DWMMC_MAX_CH_NUM);
127 
128 	for (i = 0; i < count; i++) {
129 		int node = node_list[i];
130 
131 		if (node <= 0)
132 			continue;
133 
134 		/* Extract device id for each mmc channel */
135 		dev_id = pinmux_decode_periph_id(blob, node);
136 
137 		/* Get the bus width from the device node */
138 		bus_width = fdtdec_get_int(blob, node, "samsung,bus-width", 0);
139 		if (bus_width <= 0) {
140 			debug("DWMMC: Can't get bus-width\n");
141 			return -1;
142 		}
143 		if (8 == bus_width)
144 			flag = PINMUX_FLAG_8BIT_MODE;
145 		else
146 			flag = PINMUX_FLAG_NONE;
147 
148 		/* config pinmux for each mmc channel */
149 		err = exynos_pinmux_config(dev_id, flag);
150 		if (err) {
151 			debug("DWMMC not configured\n");
152 			return err;
153 		}
154 
155 		index = dev_id - PERIPH_ID_SDMMC0;
156 
157 		/* Get the base address from the device node */
158 		base = fdtdec_get_addr(blob, node, "reg");
159 		if (!base) {
160 			debug("DWMMC: Can't get base address\n");
161 			return -1;
162 		}
163 		/* Extract the timing info from the node */
164 		err = fdtdec_get_int_array(blob, node, "samsung,timing",
165 					timing, 3);
166 		if (err) {
167 			debug("Can't get sdr-timings for divider\n");
168 			return -1;
169 		}
170 
171 		clksel_val = (DWMCI_SET_SAMPLE_CLK(timing[0]) |
172 				DWMCI_SET_DRV_CLK(timing[1]) |
173 				DWMCI_SET_DIV_RATIO(timing[2]));
174 		/* Initialise each mmc channel */
175 		err = exynos_dwmci_add_port(index, base, bus_width, clksel_val);
176 		if (err)
177 			debug("dwmmc Channel-%d init failed\n", index);
178 	}
179 	return 0;
180 }
181 #endif
182