arch/x86/cpu/broadwell/lpc.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Copyright (c) 2016 Google, Inc
   4  *
   5  * From coreboot broadwell support
   6  */
   7
   8 #include <common.h>
   9 #include <dm.h>
  10 #include <log.h>
  11 #include <pch.h>
  12 #include <asm/global_data.h>
  13 #include <asm/intel_regs.h>
  14 #include <asm/io.h>
  15 #include <asm/lpc_common.h>
  16 #include <asm/arch/pch.h>
  17 #include <asm/arch/spi.h>
  18
  19 static void set_spi_speed(void)
  20 {
  21         u32 fdod;
  22         u8 ssfc;
  23
  24         /* Observe SPI Descriptor Component Section 0 */
  25         writel(0x1000, SPI_REG(SPIBAR_FDOC));
  26
  27         /* Extract the Write/Erase SPI Frequency from descriptor */
  28         fdod = readl(SPI_REG(SPIBAR_FDOD));
  29         fdod >>= 24;
  30         fdod &= 7;
  31
  32         /* Set Software Sequence frequency to match */
  33         ssfc = readb(SPI_REG(SPIBAR_SSFC + 2));
  34         ssfc &= ~7;
  35         ssfc |= fdod;
  36         writeb(ssfc, SPI_REG(SPIBAR_SSFC + 2));
  37 }
  38
  39 static int broadwell_lpc_early_init(struct udevice *dev)
  40 {
  41         set_spi_speed();
  42
  43         return 0;
  44 }
  45
  46 static int lpc_init_extra(struct udevice *dev)
  47 {
  48         return 0;
  49 }
  50
  51 static int broadwell_lpc_probe(struct udevice *dev)
  52 {
  53         int ret;
  54
  55         if (!(gd->flags & GD_FLG_RELOC)) {
  56                 ret = lpc_common_early_init(dev);
  57                 if (ret) {
  58                         debug("%s: lpc_early_init() failed\n", __func__);
  59                         return ret;
  60                 }
  61
  62                 return broadwell_lpc_early_init(dev);
  63         }
  64
  65         return lpc_init_extra(dev);
  66 }
  67
  68 static const struct udevice_id broadwell_lpc_ids[] = {
  69         { .compatible = "intel,broadwell-lpc" },
  70         { }
  71 };
  72
  73 U_BOOT_DRIVER(broadwell_lpc_drv) = {
  74         .name           = "lpc",
  75         .id             = UCLASS_LPC,
  76         .of_match       = broadwell_lpc_ids,
  77         .probe          = broadwell_lpc_probe,
  78 };