1// SPDX-License-Identifier: GPL-2.0
2/*
3 * SDHCI driver for Synopsys DWC_MSHC controller
4 *
5 * Copyright (C) 2018 Synopsys, Inc. (www.synopsys.com)
6 *
7 * Authors:
8 * Prabu Thangamuthu <prabu.t@synopsys.com>
9 * Manjunath M B <manjumb@synopsys.com>
10 */
11
12#include "sdhci.h"
13#include "sdhci-pci.h"
14
15#define SDHCI_VENDOR_PTR_R 0xE8
16
17/* Synopsys vendor specific registers */
18#define SDHC_GPIO_OUT 0x34
19#define SDHC_AT_CTRL_R 0x40
20#define SDHC_SW_TUNE_EN 0x00000010
21
22/* MMCM DRP */
23#define SDHC_MMCM_DIV_REG 0x1020
24#define DIV_REG_100_MHZ 0x1145
25#define DIV_REG_200_MHZ 0x1083
26#define SDHC_MMCM_CLKFBOUT 0x1024
27#define CLKFBOUT_100_MHZ 0x0000
28#define CLKFBOUT_200_MHZ 0x0080
29#define SDHC_CCLK_MMCM_RST 0x00000001
30
31static void sdhci_snps_set_clock(struct sdhci_host *host, unsigned int clock)
32{
33 u16 clk;
34 u32 reg, vendor_ptr;
35
36 vendor_ptr = sdhci_readw(host, SDHCI_VENDOR_PTR_R);
37
38 /* Disable software managed rx tuning */
39 reg = sdhci_readl(host, reg: (SDHC_AT_CTRL_R + vendor_ptr));
40 reg &= ~SDHC_SW_TUNE_EN;
41 sdhci_writel(host, val: reg, reg: (SDHC_AT_CTRL_R + vendor_ptr));
42
43 if (clock <= 52000000) {
44 sdhci_set_clock(host, clock);
45 } else {
46 /* Assert reset to MMCM */
47 reg = sdhci_readl(host, reg: (SDHC_GPIO_OUT + vendor_ptr));
48 reg |= SDHC_CCLK_MMCM_RST;
49 sdhci_writel(host, val: reg, reg: (SDHC_GPIO_OUT + vendor_ptr));
50
51 /* Configure MMCM */
52 if (clock == 100000000) {
53 sdhci_writel(host, DIV_REG_100_MHZ, SDHC_MMCM_DIV_REG);
54 sdhci_writel(host, CLKFBOUT_100_MHZ,
55 SDHC_MMCM_CLKFBOUT);
56 } else {
57 sdhci_writel(host, DIV_REG_200_MHZ, SDHC_MMCM_DIV_REG);
58 sdhci_writel(host, CLKFBOUT_200_MHZ,
59 SDHC_MMCM_CLKFBOUT);
60 }
61
62 /* De-assert reset to MMCM */
63 reg = sdhci_readl(host, reg: (SDHC_GPIO_OUT + vendor_ptr));
64 reg &= ~SDHC_CCLK_MMCM_RST;
65 sdhci_writel(host, val: reg, reg: (SDHC_GPIO_OUT + vendor_ptr));
66
67 /* Enable clock */
68 clk = SDHCI_PROG_CLOCK_MODE | SDHCI_CLOCK_INT_EN |
69 SDHCI_CLOCK_CARD_EN;
70 sdhci_writew(host, val: clk, SDHCI_CLOCK_CONTROL);
71 }
72}
73
74static const struct sdhci_ops sdhci_snps_ops = {
75 .set_clock = sdhci_snps_set_clock,
76 .enable_dma = sdhci_pci_enable_dma,
77 .set_bus_width = sdhci_set_bus_width,
78 .reset = sdhci_reset,
79 .set_uhs_signaling = sdhci_set_uhs_signaling,
80};
81
82const struct sdhci_pci_fixes sdhci_snps = {
83 .ops = &sdhci_snps_ops,
84};
85

source code of linux/drivers/mmc/host/sdhci-pci-dwc-mshc.c