media: add SECO cec driver

This patch adds support to the CEC device implemented with a STM32
microcontroller in X86 SECO Boards, including UDOO X86.

The communication is achieved via Braswell integrated SMBus
(i2c-i801). The driver use direct access to the PCI addresses, due to
the limitations of the specific driver in presence of ACPI calls.

The basic functionalities are tested with success with cec-ctl and
cec-compliance.

Inspired by cros-ec-cec implementation, attaches to i915 driver
cec-notifier.
Signed-off-by: Ettore Chimenti <ek5.chimenti@gmail.com>
Reviewed-by: Jacopo Mondi <jacopo@jmondi.org>
Signed-off-by: Hans Verkuil <hansverk@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>

MAINTAINERS

@@ -13257,6 +13257,12 @@ L:	sdricohcs-devel@lists.sourceforge.net (subscribers-only)
 S:	Maintained
 F:	drivers/mmc/host/sdricoh_cs.c
 
+SECO BOARDS CEC DRIVER
+M:	Ettore Chimenti <ek5.chimenti@gmail.com>
+S:	Maintained
+F:	drivers/media/platform/seco-cec/seco-cec.c
+F:	drivers/media/platform/seco-cec/seco-cec.h
+
 SECURE COMPUTING
 M:	Kees Cook <keescook@chromium.org>
 R:	Andy Lutomirski <luto@amacapital.net>

drivers/media/platform/Kconfig

@@ -625,6 +625,18 @@ config VIDEO_TEGRA_HDMI_CEC
 	 The CEC bus is present in the HDMI connector and enables communication
 	 between compatible devices.
 
+config VIDEO_SECO_CEC
+	tristate "SECO Boards HDMI CEC driver"
+	depends on (X86 || IA64) || COMPILE_TEST
+	depends on PCI && DMI
+	select CEC_CORE
+	select CEC_NOTIFIER
+	help
+	  This is a driver for SECO Boards integrated CEC interface.
+	  Selecting it will enable support for this device.
+	  CEC bus is present in the HDMI connector and enables communication
+	  between compatible devices.
+
 endif #CEC_PLATFORM_DRIVERS
 
 menuconfig SDR_PLATFORM_DRIVERS

drivers/media/platform/Makefile

@@ -55,6 +55,8 @@ obj-$(CONFIG_VIDEO_TEGRA_HDMI_CEC)	+= tegra-cec/
 
 obj-y					+= stm32/
 
+obj-$(CONFIG_VIDEO_SECO_CEC)		+= seco-cec/
+
 obj-y					+= davinci/
 
 obj-$(CONFIG_VIDEO_SH_VOU)		+= sh_vou.o

drivers/media/platform/seco-cec/Makefile

+obj-y += seco-cec.o

drivers/media/platform/seco-cec/seco-cec.h

+/* SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause */
+/*
+ * SECO X86 Boards CEC register defines
+ *
+ * Author:  Ettore Chimenti <ek5.chimenti@gmail.com>
+ * Copyright (C) 2018, SECO Spa.
+ * Copyright (C) 2018, Aidilab Srl.
+ */
+
+#ifndef __SECO_CEC_H__
+#define __SECO_CEC_H__
+
+#define SECOCEC_MAX_ADDRS		1
+#define SECOCEC_DEV_NAME		"secocec"
+#define SECOCEC_LATEST_FW		0x0f0b
+
+#define SMBTIMEOUT			0xfff
+#define SMB_POLL_UDELAY			10
+
+#define SMBUS_WRITE			0
+#define SMBUS_READ			1
+
+#define CMD_BYTE_DATA			0
+#define CMD_WORD_DATA			1
+
+/*
+ * SMBus definitons for Braswell
+ */
+
+#define BRA_DONE_STATUS			BIT(7)
+#define BRA_INUSE_STS			BIT(6)
+#define BRA_FAILED_OP			BIT(4)
+#define BRA_BUS_ERR			BIT(3)
+#define BRA_DEV_ERR			BIT(2)
+#define BRA_INTR			BIT(1)
+#define BRA_HOST_BUSY			BIT(0)
+#define BRA_HSTS_ERR_MASK   (BRA_FAILED_OP | BRA_BUS_ERR | BRA_DEV_ERR)
+
+#define BRA_PEC_EN			BIT(7)
+#define BRA_START			BIT(6)
+#define BRA_LAST__BYTE			BIT(5)
+#define BRA_INTREN			BIT(0)
+#define BRA_SMB_CMD			(7 << 2)
+#define BRA_SMB_CMD_QUICK		(0 << 2)
+#define BRA_SMB_CMD_BYTE		(1 << 2)
+#define BRA_SMB_CMD_BYTE_DATA		(2 << 2)
+#define BRA_SMB_CMD_WORD_DATA		(3 << 2)
+#define BRA_SMB_CMD_PROCESS_CALL	(4 << 2)
+#define BRA_SMB_CMD_BLOCK		(5 << 2)
+#define BRA_SMB_CMD_I2CREAD		(6 << 2)
+#define BRA_SMB_CMD_BLOCK_PROCESS	(7 << 2)
+
+#define BRA_SMB_BASE_ADDR  0x2040
+#define HSTS               (BRA_SMB_BASE_ADDR + 0)
+#define HCNT               (BRA_SMB_BASE_ADDR + 2)
+#define HCMD               (BRA_SMB_BASE_ADDR + 3)
+#define XMIT_SLVA          (BRA_SMB_BASE_ADDR + 4)
+#define HDAT0              (BRA_SMB_BASE_ADDR + 5)
+#define HDAT1              (BRA_SMB_BASE_ADDR + 6)
+
+/*
+ * Microcontroller Address
+ */
+
+#define SECOCEC_MICRO_ADDRESS		0x40
+
+/*
+ * STM32 SMBus Registers
+ */
+
+#define SECOCEC_VERSION			0x00
+#define SECOCEC_ENABLE_REG_1		0x01
+#define SECOCEC_ENABLE_REG_2		0x02
+#define SECOCEC_STATUS_REG_1		0x03
+#define SECOCEC_STATUS_REG_2		0x04
+
+#define SECOCEC_STATUS			0x28
+#define SECOCEC_DEVICE_LA		0x29
+#define SECOCEC_READ_OPERATION_ID	0x2a
+#define SECOCEC_READ_DATA_LENGTH	0x2b
+#define SECOCEC_READ_DATA_00		0x2c
+#define SECOCEC_READ_DATA_02		0x2d
+#define SECOCEC_READ_DATA_04		0x2e
+#define SECOCEC_READ_DATA_06		0x2f
+#define SECOCEC_READ_DATA_08		0x30
+#define SECOCEC_READ_DATA_10		0x31
+#define SECOCEC_READ_DATA_12		0x32
+#define SECOCEC_READ_BYTE0		0x33
+#define SECOCEC_WRITE_OPERATION_ID	0x34
+#define SECOCEC_WRITE_DATA_LENGTH	0x35
+#define SECOCEC_WRITE_DATA_00		0x36
+#define SECOCEC_WRITE_DATA_02		0x37
+#define SECOCEC_WRITE_DATA_04		0x38
+#define SECOCEC_WRITE_DATA_06		0x39
+#define SECOCEC_WRITE_DATA_08		0x3a
+#define SECOCEC_WRITE_DATA_10		0x3b
+#define SECOCEC_WRITE_DATA_12		0x3c
+#define SECOCEC_WRITE_BYTE0		0x3d
+
+#define SECOCEC_IR_READ_DATA		0x3e
+
+/*
+ * Enabling register
+ */
+
+#define SECOCEC_ENABLE_REG_1_CEC		0x1000
+#define SECOCEC_ENABLE_REG_1_IR			0x2000
+#define SECOCEC_ENABLE_REG_1_IR_PASSTHROUGH	0x4000
+
+/*
+ * Status register
+ */
+
+#define SECOCEC_STATUS_REG_1_CEC	SECOCEC_ENABLE_REG_1_CEC
+#define SECOCEC_STATUS_REG_1_IR		SECOCEC_ENABLE_REG_1_IR
+#define SECOCEC_STATUS_REG_1_IR_PASSTHR	SECOCEC_ENABLE_REG_1_IR_PASSTHR
+
+/*
+ * Status data
+ */
+
+#define SECOCEC_STATUS_MSG_RECEIVED_MASK	BIT(0)
+#define SECOCEC_STATUS_RX_ERROR_MASK		BIT(1)
+#define SECOCEC_STATUS_MSG_SENT_MASK		BIT(2)
+#define SECOCEC_STATUS_TX_ERROR_MASK		BIT(3)
+
+#define SECOCEC_STATUS_TX_NACK_ERROR		BIT(4)
+#define SECOCEC_STATUS_RX_OVERFLOW_MASK		BIT(5)
+
+#endif /* __SECO_CEC_H__ */