x86: apl: Add LPC driver
This driver the LPC and provides a few functions to set up LPC features.
These should probably use ioctls() or perhaps, better, have specific
uclass methods.
Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
diff --git a/arch/x86/cpu/apollolake/Makefile b/arch/x86/cpu/apollolake/Makefile
index 2d78368..31045a0 100644
--- a/arch/x86/cpu/apollolake/Makefile
+++ b/arch/x86/cpu/apollolake/Makefile
@@ -6,5 +6,6 @@
obj-y += hostbridge.o
obj-y += itss.o
+obj-y += lpc.o
obj-y += pmc.o
obj-y += uart.o
diff --git a/arch/x86/cpu/apollolake/lpc.c b/arch/x86/cpu/apollolake/lpc.c
new file mode 100644
index 0000000..45b2144
--- /dev/null
+++ b/arch/x86/cpu/apollolake/lpc.c
@@ -0,0 +1,122 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright 2019 Google LLC
+ *
+ * From coreboot Apollo Lake support lpc.c
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <spl.h>
+#include <asm/lpc_common.h>
+#include <asm/pci.h>
+#include <asm/arch/iomap.h>
+#include <asm/arch/lpc.h>
+#include <linux/log2.h>
+
+void lpc_enable_fixed_io_ranges(uint io_enables)
+{
+ pci_x86_clrset_config(PCH_DEV_LPC, LPC_IO_ENABLES, 0, io_enables,
+ PCI_SIZE_16);
+}
+
+/*
+ * Find the first unused IO window.
+ * Returns -1 if not found, 0 for reg 0x84, 1 for reg 0x88 ...
+ */
+static int find_unused_pmio_window(void)
+{
+ int i;
+ ulong lgir;
+
+ for (i = 0; i < LPC_NUM_GENERIC_IO_RANGES; i++) {
+ pci_x86_read_config(PCH_DEV_LPC, LPC_GENERIC_IO_RANGE(i),
+ &lgir, PCI_SIZE_32);
+
+ if (!(lgir & LPC_LGIR_EN))
+ return i;
+ }
+
+ return -1;
+}
+
+int lpc_open_pmio_window(uint base, uint size)
+{
+ int i, lgir_reg_num;
+ u32 lgir_reg_offset, lgir, window_size, alignment;
+ ulong bridged_size, bridge_base;
+ ulong reg;
+
+ log_debug("LPC: Trying to open IO window from %x size %x\n", base,
+ size);
+
+ bridged_size = 0;
+ bridge_base = base;
+
+ while (bridged_size < size) {
+ /* Each IO range register can only open a 256-byte window */
+ window_size = min(size, (uint)LPC_LGIR_MAX_WINDOW_SIZE);
+
+ /* Window size must be a power of two for the AMASK to work */
+ alignment = 1UL << (order_base_2(window_size));
+ window_size = ALIGN(window_size, alignment);
+
+ /* Address[15:2] in LGIR[15:12] and Mask[7:2] in LGIR[23:18] */
+ lgir = (bridge_base & LPC_LGIR_ADDR_MASK) | LPC_LGIR_EN;
+ lgir |= ((window_size - 1) << 16) & LPC_LGIR_AMASK_MASK;
+
+ /* Skip programming if same range already programmed */
+ for (i = 0; i < LPC_NUM_GENERIC_IO_RANGES; i++) {
+ pci_x86_read_config(PCH_DEV_LPC,
+ LPC_GENERIC_IO_RANGE(i), ®,
+ PCI_SIZE_32);
+ if (lgir == reg)
+ return -EALREADY;
+ }
+
+ lgir_reg_num = find_unused_pmio_window();
+ if (lgir_reg_num < 0) {
+ log_err("LPC: Cannot open IO window: %lx size %lx\n",
+ bridge_base, size - bridged_size);
+ log_err("No more IO windows\n");
+
+ return -ENOSPC;
+ }
+ lgir_reg_offset = LPC_GENERIC_IO_RANGE(lgir_reg_num);
+
+ pci_x86_write_config(PCH_DEV_LPC, lgir_reg_offset, lgir,
+ PCI_SIZE_32);
+
+ log_debug("LPC: Opened IO window LGIR%d: base %lx size %x\n",
+ lgir_reg_num, bridge_base, window_size);
+
+ bridged_size += window_size;
+ bridge_base += window_size;
+ }
+
+ return 0;
+}
+
+void lpc_io_setup_comm_a_b(void)
+{
+ /* ComA Range 3F8h-3FFh [2:0] */
+ u16 com_ranges = LPC_IOD_COMA_RANGE;
+ u16 com_enable = LPC_IOE_COMA_EN;
+
+ /* Setup I/O Decode Range Register for LPC */
+ pci_write_config16(PCH_DEV_LPC, LPC_IO_DECODE, com_ranges);
+ /* Enable ComA and ComB Port */
+ lpc_enable_fixed_io_ranges(com_enable);
+}
+
+static const struct udevice_id apl_lpc_ids[] = {
+ { .compatible = "intel,apl-lpc" },
+ { }
+};
+
+/* All pads are LPC already configured by the hostbridge, so no probing here */
+U_BOOT_DRIVER(apl_lpc_drv) = {
+ .name = "intel_apl_lpc",
+ .id = UCLASS_LPC,
+ .of_match = apl_lpc_ids,
+};