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