siemens/mc_apl1: Extend circuit life by clock gating and power gating

The firmware of devices connected to LPC should deassert the LPC CLKRUN#
signal when there is no bus activity on LPC.

Necessary changes:

- Enable LPC CLKRUN#
- Enable LPC PCE (Power Control Enable)
- Enable LPC CCE (Clock Control Enable)
- Remove I/O decoding range on LPC for COM 3
- Disable I/O UART driver

Change-Id: I2fd80e3fdcf23658f97b8182a77df7e09ddf25d6
Signed-off-by: Mario Scheithauer <mario.scheithauer@siemens.com>
Reviewed-on: https://review.coreboot.org/28268
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Werner Zeh <werner.zeh@siemens.com>
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>

src/mainboard/siemens/mc_apl1/variants/baseboard/gpio.c

@@ -84,7 +84,7 @@ static const struct pad_config gpio_table[] = {
 	PAD_CFG_NF(LPC_AD1, NONE, DEEP, NF1),		/* LPC_AD1 */
 	PAD_CFG_NF(LPC_AD2, NONE, DEEP, NF1),		/* LPC_AD2 */
 	PAD_CFG_NF(LPC_AD3, NONE, DEEP, NF1),		/* LPC_AD3 */
-	PAD_CFG_GPI(LPC_CLKRUNB, NONE, DEEP),		/* LPC_CLKRUN_N */
+	PAD_CFG_NF(LPC_CLKRUNB, NONE, DEEP, NF1),	/* LPC_CLKRUN_N */
 	PAD_CFG_NF(LPC_FRAMEB, NONE, DEEP, NF1),	/* LPC_FRAME_N */
 
 	/* West Community */
@@ -402,7 +402,7 @@ static const struct pad_config early_gpio_table[] = {
 	PAD_CFG_NF(LPC_AD1, NONE, DEEP, NF1),		/* LPC_AD1 */
 	PAD_CFG_NF(LPC_AD2, NONE, DEEP, NF1),		/* LPC_AD2 */
 	PAD_CFG_NF(LPC_AD3, NONE, DEEP, NF1),		/* LPC_AD3 */
-	PAD_CFG_GPI(LPC_CLKRUNB, NONE, DEEP),		/* LPC_CLKRUN_N */
+	PAD_CFG_NF(LPC_CLKRUNB, NONE, DEEP, NF1),	/* LPC_CLKRUN_N */
 	PAD_CFG_NF(LPC_FRAMEB, NONE, DEEP, NF1),	/* LPC_FRAME_N */
 };
 

src/mainboard/siemens/mc_apl1/variants/mc_apl1/Kconfig

@@ -5,7 +5,6 @@ config BOARD_SIEMENS_MC_APL1_VAR
 	def_bool y
 	select DRIVER_INTEL_I210
 	select DRIVERS_I2C_RX6110SA
-	select DRIVERS_UART_8250IO
 	select DRIVER_SIEMENS_NC_FPGA
 	select NC_FPGA_NOTIFY_CB_READY
 	select APL_SKIP_SET_POWER_LIMITS

src/mainboard/siemens/mc_apl1/variants/mc_apl1/mainboard.c

@@ -42,9 +42,6 @@ void variant_mainboard_final(void)
 	else
 		printk(BIOS_INFO, "LCD: Set up PTN was successful.\n");
 
-	/* Enable additional I/O decoding range on LPC for COM 3 */
-	lpc_open_pmio_window(0x3e8, 8);
-
 	/*
 	 * PIR6 register mapping for PCIe root ports
 	 * INTA#->PIRQB#, INTB#->PIRQC#, INTC#->PIRQD#, INTD#-> PIRQA#
@@ -55,6 +52,17 @@ void variant_mainboard_final(void)
 	dev = dev_find_device(PCI_VENDOR_ID_TI, PCI_DEVICE_ID_TI_XIO2001, 0);
 	if (dev)
 		pci_write_config8(dev, 0xd8, 0x3e);
+
+	/* Enable CLKRUN_EN for power gating LPC */
+	lpc_enable_pci_clk_cntl();
+
+	/*
+	 * Enable LPC PCE (Power Control Enable) by setting IOSF-SB port 0xD2
+	 * offset 0x341D bit3 and bit0.
+	 * Enable LPC CCE (Clock Control Enable) by setting IOSF-SB port 0xD2
+	 * offset 0x341C bit [3:0].
+	 */
+	pcr_or32(PID_LPC, PCR_LPC_PRC, (PCR_LPC_CCE_EN | PCR_LPC_PCE_EN));
 }
 
 static void wait_for_legacy_dev(void *unused)

src/soc/intel/apollolake/include/soc/pcr_ids.h

@@ -2,6 +2,7 @@
  * This file is part of the coreboot project.
  *
  * Copyright 2017 Intel Corporation.
+ * Copyright (C) 2018 Siemens AG
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -31,6 +32,7 @@
 #define PID_GPIO_N	0xC5
 #define PID_ITSS	0xD0
 #define PID_RTC		0xD1
+#define PID_LPC		0xD2
 
 #define PID_AUNIT	0x4d
 #define PID_BUNIT	0x4c

src/soc/intel/common/block/include/intelblocks/lpc_lib.h

@@ -2,6 +2,7 @@
  * This file is part of the coreboot project.
  *
  * Copyright (C) 2017-2018 Intel Corp.
+ * Copyright (C) 2018 Siemens AG
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -47,6 +48,11 @@
 #define PCR_DMI_LPCIOD          0x2770
 #define PCR_DMI_LPCIOE          0x2774
 
+/* LPC PCR configuration */
+#define PCR_LPC_PRC            0x341c
+#define PCR_LPC_CCE_EN         0xf
+#define PCR_LPC_PCE_EN         (9 << 8)
+
 /* Serial IRQ control. SERIRQ_QUIET is the default (0). */
 enum serirq_mode {
 	SERIRQ_QUIET,