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