intel/common/block/i2c: Add common block for I2C and use the same in SoCs

In the intel/common/block
* Move I2C common code from intel/common to intel/common/block.
* Split the code into common, early init and post mem init stages and put it
  in lpss_i2c.c, i2c_early.c and i2c.c respectively.
* Declare functions for getting platform specific i2c bus config and
  mapping bus to devfn and vice versa, that have to be implemented by SoC.

In skylake/apollolake
* Stop using code from soc/intel/common/lpss_i2c.c.
* Remove early i2c initialization code from bootblock.
* Refactor i2c.c file to implement SoC specific methods
  required by the I2C IP block.

Change-Id: I4d91a04c22e181e3a995112cce6d5f0324130b81
Signed-off-by: Rizwan Qureshi <rizwan.qureshi@intel.com>
Reviewed-on: https://review.coreboot.org/19468
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Aaron Durbin <adurbin@chromium.org>

1 files changed, 105 insertions, 0 deletions

diff --git a/src/soc/intel/common/block/include/intelblocks/lpss_i2c.h b/src/soc/intel/common/block/include/intelblocks/lpss_i2c.h
new file mode 100644
index 0000000000..2f60d654b1
--- /dev/null
+++ b/src/soc/intel/common/block/include/intelblocks/lpss_i2c.h
@@ -0,0 +1,105 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * Copyright 2016 Google Inc.
+ *
+ * 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
+ * the Free Software Foundation; version 2 of the License.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#ifndef SOC_INTEL_COMMON_BLOCK_LPSS_I2C_H
+#define SOC_INTEL_COMMON_BLOCK_LPSS_I2C_H
+
+#include <device/i2c.h>
+#include <stdint.h>
+
+/*
+ * Timing values are in units of clock period, with the clock speed
+ * provided by the SOC in CONFIG_SOC_INTEL_COMMON_LPSS_CLOCK_MHZ.
+ * Automatic configuration is done based on requested speed, but the
+ * values may need tuned depending on the board and the number of
+ * devices present on the bus.
+ */
+struct lpss_i2c_speed_config {
+	enum i2c_speed speed;
+	/* SCL high and low period count */
+	uint16_t scl_lcnt;
+	uint16_t scl_hcnt;
+	/*
+	 * SDA hold time should be 300ns in standard and fast modes
+	 * and long enough for deterministic logic level change in
+	 * fast-plus and high speed modes.
+	 *
+	 *  [15:0] SDA TX Hold Time
+	 * [23:16] SDA RX Hold Time
+	 */
+	uint32_t sda_hold;
+};
+
+/*
+ * This I2C controller has support for 3 independent speed configs but can
+ * support both FAST_PLUS and HIGH speeds through the same set of speed
+ * config registers.  These are treated separately so the speed config values
+ * can be provided via ACPI to the OS.
+ */
+#define LPSS_I2C_SPEED_CONFIG_COUNT	4
+
+struct lpss_i2c_bus_config {
+	/* Bus should be enabled prior to ramstage with temporary base */
+	int early_init;
+	/* Bus speed in Hz, default is I2C_SPEED_FAST (400 KHz) */
+	enum i2c_speed speed;
+	/* If rise_time_ns is non-zero the calculations for lcnt and hcnt
+	 * registers take into account the times of the bus. However, if
+	 * there is a match in speed_config those register values take
+	 * precedence. */
+	int rise_time_ns;
+	int fall_time_ns;
+	int data_hold_time_ns;
+	/* Specific bus speed configuration */
+	struct lpss_i2c_speed_config speed_config[LPSS_I2C_SPEED_CONFIG_COUNT];
+};
+
+#define LPSS_I2C_SPEED_CONFIG(speedval, lcnt, hcnt, hold)	\
+	{							\
+		.speed = I2C_SPEED_ ## speedval,		\
+		.scl_lcnt = (lcnt),				\
+		.scl_hcnt = (hcnt),				\
+		.sda_hold = (hold),				\
+	}
+
+/* Functions to be implemented by SoC code */
+
+/* Get base address for early init of I2C controllers. */
+uintptr_t i2c_get_soc_early_base(unsigned int bus);
+
+/*
+ * Map given I2C bus number to devfn.
+ * Return value:
+ * -1 = error
+ * otherwise, devfn(>=0) corresponding to I2C bus number.
+ */
+int i2c_soc_devfn_to_bus(unsigned int devfn);
+
+/*
+ * Map given bus number to a I2C Controller.
+ * Return value:
+ * -1 = error
+ * otherwise, devfn(>=0) corresponding to I2C bus number.
+ */
+int i2c_soc_bus_to_devfn(unsigned int bus);
+
+/*
+ * SoC implemented callback for getting I2C bus configuration.
+ *
+ * Returns NULL if i2c config is not found
+ */
+const struct lpss_i2c_bus_config *i2c_get_soc_cfg(unsigned int bus,
+						const struct device *dev);
+#endif /* SOC_INTEL_COMMON_BLOCK_LPSS_I2C_H */