root/drivers/mmc/host/sdhci-pci-dwc-mshc.c

DEFINITIONS

1. sdhci_snps_set_clock

   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 
  31 static 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, (SDHC_AT_CTRL_R + vendor_ptr));
  40         reg &= ~SDHC_SW_TUNE_EN;
  41         sdhci_writel(host, 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, (SDHC_GPIO_OUT + vendor_ptr));
  48                 reg |= SDHC_CCLK_MMCM_RST;
  49                 sdhci_writel(host, 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, (SDHC_GPIO_OUT + vendor_ptr));
  64                 reg &= ~SDHC_CCLK_MMCM_RST;
  65                 sdhci_writel(host, 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, clk, SDHCI_CLOCK_CONTROL);
  71         }
  72 }
  73 
  74 static 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 
  82 const struct sdhci_pci_fixes sdhci_snps = {
  83         .ops            = &sdhci_snps_ops,
  84 };