xref: /openbmc/u-boot/drivers/mmc/exynos_dw_mmc.c (revision bcc05c7a)
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(int dev_index)
33 {
34 	return get_mmc_clk(dev_index);
35 }
36 
37 /*
38  * This function adds the mmc channel to be registered with mmc core.
39  * index -	mmc channel number.
40  * regbase -	register base address of mmc channel specified in 'index'.
41  * bus_width -	operating bus width of mmc channel specified in 'index'.
42  * clksel -	value to be written into CLKSEL register in case of FDT.
43  *		NULL in case od non-FDT.
44  */
45 int exynos_dwmci_add_port(int index, u32 regbase, int bus_width, u32 clksel)
46 {
47 	struct dwmci_host *host = NULL;
48 	unsigned int div;
49 	unsigned long freq, sclk;
50 	host = malloc(sizeof(struct dwmci_host));
51 	if (!host) {
52 		printf("dwmci_host malloc fail!\n");
53 		return 1;
54 	}
55 	/* request mmc clock vlaue of 52MHz.  */
56 	freq = 52000000;
57 	sclk = get_mmc_clk(index);
58 	div = DIV_ROUND_UP(sclk, freq);
59 	/* set the clock divisor for mmc */
60 	set_mmc_clk(index, div);
61 
62 	host->name = "EXYNOS DWMMC";
63 	host->ioaddr = (void *)regbase;
64 	host->buswidth = bus_width;
65 
66 	if (clksel) {
67 		host->clksel_val = clksel;
68 	} else {
69 		if (0 == index)
70 			host->clksel_val = DWMMC_MMC0_CLKSEL_VAL;
71 		if (2 == index)
72 			host->clksel_val = DWMMC_MMC2_CLKSEL_VAL;
73 	}
74 
75 	host->clksel = exynos_dwmci_clksel;
76 	host->dev_index = index;
77 	host->mmc_clk = exynos_dwmci_get_clk;
78 	/* Add the mmc channel to be registered with mmc core */
79 	if (add_dwmci(host, DWMMC_MAX_FREQ, DWMMC_MIN_FREQ)) {
80 		debug("dwmmc%d registration failed\n", index);
81 		return -1;
82 	}
83 	return 0;
84 }
85 
86 #ifdef CONFIG_OF_CONTROL
87 int exynos_dwmmc_init(const void *blob)
88 {
89 	int index, bus_width;
90 	int node_list[DWMMC_MAX_CH_NUM];
91 	int err = 0, dev_id, flag, count, i;
92 	u32 clksel_val, base, timing[3];
93 
94 	count = fdtdec_find_aliases_for_id(blob, "mmc",
95 				COMPAT_SAMSUNG_EXYNOS5_DWMMC, node_list,
96 				DWMMC_MAX_CH_NUM);
97 
98 	for (i = 0; i < count; i++) {
99 		int node = node_list[i];
100 
101 		if (node <= 0)
102 			continue;
103 
104 		/* Extract device id for each mmc channel */
105 		dev_id = pinmux_decode_periph_id(blob, node);
106 
107 		/* Get the bus width from the device node */
108 		bus_width = fdtdec_get_int(blob, node, "samsung,bus-width", 0);
109 		if (bus_width <= 0) {
110 			debug("DWMMC: Can't get bus-width\n");
111 			return -1;
112 		}
113 		if (8 == bus_width)
114 			flag = PINMUX_FLAG_8BIT_MODE;
115 		else
116 			flag = PINMUX_FLAG_NONE;
117 
118 		/* config pinmux for each mmc channel */
119 		err = exynos_pinmux_config(dev_id, flag);
120 		if (err) {
121 			debug("DWMMC not configured\n");
122 			return err;
123 		}
124 
125 		index = dev_id - PERIPH_ID_SDMMC0;
126 
127 		/* Get the base address from the device node */
128 		base = fdtdec_get_addr(blob, node, "reg");
129 		if (!base) {
130 			debug("DWMMC: Can't get base address\n");
131 			return -1;
132 		}
133 		/* Extract the timing info from the node */
134 		err = fdtdec_get_int_array(blob, node, "samsung,timing",
135 					timing, 3);
136 		if (err) {
137 			debug("Can't get sdr-timings for divider\n");
138 			return -1;
139 		}
140 
141 		clksel_val = (DWMCI_SET_SAMPLE_CLK(timing[0]) |
142 				DWMCI_SET_DRV_CLK(timing[1]) |
143 				DWMCI_SET_DIV_RATIO(timing[2]));
144 		/* Initialise each mmc channel */
145 		err = exynos_dwmci_add_port(index, base, bus_width, clksel_val);
146 		if (err)
147 			debug("dwmmc Channel-%d init failed\n", index);
148 	}
149 	return 0;
150 }
151 #endif
152