xref: /openbmc/linux/drivers/mmc/host/sdhci-esdhc.h (revision e23feb16)
1 /*
2  * Freescale eSDHC controller driver generics for OF and pltfm.
3  *
4  * Copyright (c) 2007 Freescale Semiconductor, Inc.
5  * Copyright (c) 2009 MontaVista Software, Inc.
6  * Copyright (c) 2010 Pengutronix e.K.
7  *   Author: Wolfram Sang <w.sang@pengutronix.de>
8  *
9  * This program is free software; you can redistribute it and/or modify
10  * it under the terms of the GNU General Public License as published by
11  * the Free Software Foundation; either version 2 of the License.
12  */
13 
14 #ifndef _DRIVERS_MMC_SDHCI_ESDHC_H
15 #define _DRIVERS_MMC_SDHCI_ESDHC_H
16 
17 /*
18  * Ops and quirks for the Freescale eSDHC controller.
19  */
20 
21 #define ESDHC_DEFAULT_QUIRKS	(SDHCI_QUIRK_FORCE_BLK_SZ_2048 | \
22 				SDHCI_QUIRK_NO_BUSY_IRQ | \
23 				SDHCI_QUIRK_NONSTANDARD_CLOCK | \
24 				SDHCI_QUIRK_DATA_TIMEOUT_USES_SDCLK | \
25 				SDHCI_QUIRK_PIO_NEEDS_DELAY | \
26 				SDHCI_QUIRK_RESTORE_IRQS_AFTER_RESET)
27 
28 #define ESDHC_SYSTEM_CONTROL	0x2c
29 #define ESDHC_CLOCK_MASK	0x0000fff0
30 #define ESDHC_PREDIV_SHIFT	8
31 #define ESDHC_DIVIDER_SHIFT	4
32 #define ESDHC_CLOCK_PEREN	0x00000004
33 #define ESDHC_CLOCK_HCKEN	0x00000002
34 #define ESDHC_CLOCK_IPGEN	0x00000001
35 
36 /* pltfm-specific */
37 #define ESDHC_HOST_CONTROL_LE	0x20
38 
39 /*
40  * P2020 interpretation of the SDHCI_HOST_CONTROL register
41  */
42 #define ESDHC_CTRL_4BITBUS          (0x1 << 1)
43 #define ESDHC_CTRL_8BITBUS          (0x2 << 1)
44 #define ESDHC_CTRL_BUSWIDTH_MASK    (0x3 << 1)
45 
46 /* OF-specific */
47 #define ESDHC_DMA_SYSCTL	0x40c
48 #define ESDHC_DMA_SNOOP		0x00000040
49 
50 #define ESDHC_HOST_CONTROL_RES	0x05
51 
52 static inline void esdhc_set_clock(struct sdhci_host *host, unsigned int clock,
53 				   unsigned int host_clock)
54 {
55 	int pre_div = 2;
56 	int div = 1;
57 	u32 temp;
58 
59 	if (clock == 0)
60 		goto out;
61 
62 	temp = sdhci_readl(host, ESDHC_SYSTEM_CONTROL);
63 	temp &= ~(ESDHC_CLOCK_IPGEN | ESDHC_CLOCK_HCKEN | ESDHC_CLOCK_PEREN
64 		| ESDHC_CLOCK_MASK);
65 	sdhci_writel(host, temp, ESDHC_SYSTEM_CONTROL);
66 
67 	while (host_clock / pre_div / 16 > clock && pre_div < 256)
68 		pre_div *= 2;
69 
70 	while (host_clock / pre_div / div > clock && div < 16)
71 		div++;
72 
73 	dev_dbg(mmc_dev(host->mmc), "desired SD clock: %d, actual: %d\n",
74 		clock, host_clock / pre_div / div);
75 
76 	pre_div >>= 1;
77 	div--;
78 
79 	temp = sdhci_readl(host, ESDHC_SYSTEM_CONTROL);
80 	temp |= (ESDHC_CLOCK_IPGEN | ESDHC_CLOCK_HCKEN | ESDHC_CLOCK_PEREN
81 		| (div << ESDHC_DIVIDER_SHIFT)
82 		| (pre_div << ESDHC_PREDIV_SHIFT));
83 	sdhci_writel(host, temp, ESDHC_SYSTEM_CONTROL);
84 	mdelay(1);
85 out:
86 	host->clock = clock;
87 }
88 
89 #endif /* _DRIVERS_MMC_SDHCI_ESDHC_H */
90