chip/stm32/usb_i2c: Remove obsolete implementation

Since a04fc68e721 "usb_i2c: refactor into common", the code in
chip/stm32/usb_i2c.* is dead, let's remove it to avoid confusion.

BRANCH=none
BUG=b:35578857
TEST=On hammer, userspace application can still talk to trackpad.

Change-Id: Idd9cc1109c80f3949fa8c4e50f4fe2e267d5a7ae
Reviewed-on: https://chromium-review.googlesource.com/492768
Commit-Ready: Nicolas Boichat <drinkcat@chromium.org>
Tested-by: Chun-ta Lin <itspeter@chromium.org>
Reviewed-by: Nick Sanders <nsanders@chromium.org>

2 files changed, 0 insertions, 322 deletions

diff --git a/chip/stm32/usb_i2c.c b/chip/stm32/usb_i2c.c
deleted file mode 100644
index 1cc13bc304..0000000000
--- a/chip/stm32/usb_i2c.c
+++ /dev/null
@@ -1,140 +0,0 @@
-/* Copyright 2016 The Chromium OS Authors. All rights reserved.
- * Use of this source code is governed by a BSD-style license that can be
- * found in the LICENSE file.
- */
-
-#include "common.h"
-#include "link_defs.h"
-#include "registers.h"
-#include "i2c.h"
-#include "usb_descriptor.h"
-#include "usb_i2c.h"
-#include "util.h"
-
-#define CPRINTS(format, args...) cprints(CC_I2C, format, ## args)
-
-
-static int16_t usb_i2c_map_error(int error)
-{
-	switch (error) {
-	case EC_SUCCESS:       return USB_I2C_SUCCESS;
-	case EC_ERROR_TIMEOUT: return USB_I2C_TIMEOUT;
-	case EC_ERROR_BUSY:    return USB_I2C_BUSY;
-	default:               return USB_I2C_UNKNOWN_ERROR | (error & 0x7fff);
-	}
-}
-
-static uint8_t usb_i2c_read_packet(struct usb_i2c_config const *config)
-{
-	size_t  i;
-	uint16_t bytes = btable_ep[config->endpoint].rx_count & 0x3ff;
-	size_t   count = MAX((bytes + 1) / 2, USB_MAX_PACKET_SIZE / 2);
-
-	/*
-	 * The USB peripheral doesn't support DMA access to its packet
-	 * RAM so we have to copy messages out into a bounce buffer.
-	 */
-	for (i = 0; i < count; ++i)
-		config->buffer[i] = config->rx_ram[i];
-
-	/*
-	 * RX packet consumed, mark the packet as VALID.  The master
-	 * could queue up the next command while we process this I2C
-	 * transaction and prepare the response.
-	 */
-	STM32_TOGGLE_EP(config->endpoint, EP_RX_MASK, EP_RX_VALID, 0);
-
-	return bytes;
-}
-
-static void usb_i2c_write_packet(struct usb_i2c_config const *config,
-				 uint8_t count)
-{
-	size_t  i;
-	/* count is bounds checked in usb_i2c_deferred. */
-
-	/*
-	 * Copy read bytes and status back out of bounce buffer and
-	 * update TX packet state (mark as VALID for master to read).
-	 */
-	for (i = 0; i < (count + 1) / 2; ++i)
-		config->tx_ram[i] = config->buffer[i];
-
-	btable_ep[config->endpoint].tx_count = count;
-
-	STM32_TOGGLE_EP(config->endpoint, EP_TX_MASK, EP_TX_VALID, 0);
-}
-
-static int rx_valid(struct usb_i2c_config const *config)
-{
-	return (STM32_USB_EP(config->endpoint) & EP_RX_MASK) == EP_RX_VALID;
-}
-
-void usb_i2c_deferred(struct usb_i2c_config const *config)
-{
-	/*
-	 * And if there is a USB packet waiting we process it and generate a
-	 * response.
-	 */
-	if (!rx_valid(config)) {
-		uint16_t count      = usb_i2c_read_packet(config);
-		int portindex       = (config->buffer[0] >> 0) & 0xff;
-
-		/* Convert 7-bit slave address to stm32 8-bit address. */
-		uint8_t slave_addr  = (config->buffer[0] >> 7) & 0xfe;
-		int write_count     = (config->buffer[1] >> 0) & 0xff;
-		int read_count      = (config->buffer[1] >> 8) & 0xff;
-		int port = 0;
-
-		config->buffer[0] = 0;
-		config->buffer[1] = 0;
-
-		if (write_count > USB_I2C_MAX_WRITE_COUNT ||
-		    write_count != (count - 4)) {
-			config->buffer[0] = USB_I2C_WRITE_COUNT_INVALID;
-		} else if (read_count > USB_I2C_MAX_READ_COUNT) {
-			config->buffer[0] = USB_I2C_READ_COUNT_INVALID;
-		} else if (portindex >= i2c_ports_used) {
-			config->buffer[0] = USB_I2C_PORT_INVALID;
-		} else {
-			port = i2c_ports[portindex].port;
-			config->buffer[0] = usb_i2c_map_error(
-				i2c_xfer(port, slave_addr,
-					(uint8_t *)(config->buffer + 2),
-					write_count,
-					(uint8_t *)(config->buffer + 2),
-					read_count, I2C_XFER_SINGLE));
-		}
-
-		usb_i2c_write_packet(config, read_count + 4);
-	}
-}
-
-void usb_i2c_tx(struct usb_i2c_config const *config)
-{
-	STM32_TOGGLE_EP(config->endpoint, EP_TX_MASK, EP_TX_NAK, 0);
-}
-
-void usb_i2c_rx(struct usb_i2c_config const *config)
-{
-	STM32_TOGGLE_EP(config->endpoint, EP_RX_MASK, EP_RX_NAK, 0);
-
-	hook_call_deferred(config->deferred, 0);
-}
-
-void usb_i2c_reset(struct usb_i2c_config const *config)
-{
-	int endpoint = config->endpoint;
-
-	btable_ep[endpoint].tx_addr  = usb_sram_addr(config->tx_ram);
-	btable_ep[endpoint].tx_count = 0;
-
-	btable_ep[endpoint].rx_addr  = usb_sram_addr(config->rx_ram);
-	btable_ep[endpoint].rx_count =
-		0x8000 | ((USB_MAX_PACKET_SIZE / 32 - 1) << 10);
-
-	STM32_USB_EP(endpoint) = ((endpoint <<  0) | /* Endpoint Addr*/
-				  (2        <<  4) | /* TX NAK */
-				  (0        <<  9) | /* Bulk EP */
-				  (3        << 12)); /* RX Valid */
-}
diff --git a/chip/stm32/usb_i2c.h b/chip/stm32/usb_i2c.h
deleted file mode 100644
index 34e2da7b2a..0000000000
--- a/chip/stm32/usb_i2c.h
+++ /dev/null
@@ -1,182 +0,0 @@
-/* Copyright 2016 The Chromium OS Authors. All rights reserved.
- * Use of this source code is governed by a BSD-style license that can be
- * found in the LICENSE file.
- */
-#ifndef __CROS_EC_USB_I2C_H
-#define __CROS_EC_USB_I2C_H
-
-/* STM32 USB I2C driver for Chrome EC */
-
-#include "compile_time_macros.h"
-#include "hooks.h"
-#include "usb_descriptor.h"
-
-/*
- * Command:
- *     +----------+-----------+---------------+---------------+---------------+
- *     | port: 1B | addr: 1B  | wr count : 1B | rd count : 1B | data : <= 60B |
- *     +----------+-----------+---------------+---------------+---------------+
- *
- *     port address:  1 byte, stm32 i2c interface index
- *
- *     slave address: 1 byte, i2c 7-bit bus address
- *
- *     write count:   1 byte, zero based count of bytes to write
- *
- *     read count:    1 byte, zero based count of bytes to read
- *
- *     data:          write payload up to 60 bytes of data to write,
- *                    length must match write count
- *
- * Response:
- *     +-------------+---+---+-----------------------+
- *     | status : 2B | 0 | 0 | read payload : <= 60B |
- *     +-------------+---+---+-----------------------+
- *
- *     status: 2 byte status
- *         0x0000: Success
- *         0x0001: I2C timeout
- *         0x0002: Busy, try again
- *             This can happen if someone else has acquired the shared memory
- *             buffer that the I2C driver uses as /dev/null
- *         0x0003: Write count invalid (> 60 bytes, or mismatch with payload)
- *         0x0004: Read count invalid (> 60 bytes)
- *         0x0005: The port specified is invalid.
- *         0x8000: Unknown error mask
- *             The bottom 15 bits will contain the bottom 15 bits from the EC
- *             error code.
- *
- *     read payload: up to 60 bytes of data read from I2C, length will match
- *                   requested read count
- */
-
-enum usb_i2c_error {
-	USB_I2C_SUCCESS             = 0x0000,
-	USB_I2C_TIMEOUT             = 0x0001,
-	USB_I2C_BUSY                = 0x0002,
-	USB_I2C_WRITE_COUNT_INVALID = 0x0003,
-	USB_I2C_READ_COUNT_INVALID  = 0x0004,
-	USB_I2C_PORT_INVALID        = 0x0005,
-	USB_I2C_UNKNOWN_ERROR       = 0x8000,
-};
-
-
-#define USB_I2C_MAX_WRITE_COUNT 60
-#define USB_I2C_MAX_READ_COUNT  60
-
-BUILD_ASSERT(USB_MAX_PACKET_SIZE == (1 + 1 + 1 + 1 + USB_I2C_MAX_WRITE_COUNT));
-BUILD_ASSERT(USB_MAX_PACKET_SIZE == (2 + 1 + 1 + USB_I2C_MAX_READ_COUNT));
-
-/*
- * Compile time Per-USB gpio configuration stored in flash.  Instances of this
- * structure are provided by the user of the USB gpio.  This structure binds
- * together all information required to operate a USB gpio.
- */
-struct usb_i2c_config {
-	/*
-	 * Interface and endpoint indicies.
-	 */
-	int interface;
-	int endpoint;
-
-	/*
-	 * Deferred function to call to handle I2C request.
-	 */
-	const struct deferred_data *deferred;
-
-	/*
-	 * Pointers to USB packet RAM and bounce buffer.
-	 */
-	uint16_t *buffer;
-	usb_uint *rx_ram;
-	usb_uint *tx_ram;
-};
-
-/*
- * Convenience macro for defining a USB I2C bridge driver.
- *
- * NAME is used to construct the names of the trampoline functions and the
- * usb_i2c_config struct, the latter is just called NAME.
- *
- * INTERFACE is the index of the USB interface to associate with this
- * I2C driver.
- *
- * ENDPOINT is the index of the USB bulk endpoint used for receiving and
- * transmitting bytes.
- */
-#define USB_I2C_CONFIG(NAME,						\
-		       INTERFACE,					\
-		       ENDPOINT)					\
-	static uint16_t							\
-		CONCAT2(NAME, _buffer_)[USB_MAX_PACKET_SIZE / 2];	\
-	static usb_uint CONCAT2(NAME, _ep_rx_buffer_)			\
-		[USB_MAX_PACKET_SIZE / 2] __usb_ram;			\
-	static usb_uint CONCAT2(NAME, _ep_tx_buffer_)			\
-		[USB_MAX_PACKET_SIZE / 2] __usb_ram;			\
-	static void CONCAT2(NAME, _deferred_)(void);			\
-	DECLARE_DEFERRED(CONCAT2(NAME, _deferred_));			\
-	struct usb_i2c_config const NAME = {				\
-		.interface = INTERFACE,					\
-		.endpoint  = ENDPOINT,					\
-		.deferred  = &CONCAT2(NAME, _deferred__data),		\
-		.buffer    = CONCAT2(NAME, _buffer_),			\
-		.rx_ram    = CONCAT2(NAME, _ep_rx_buffer_),		\
-		.tx_ram    = CONCAT2(NAME, _ep_tx_buffer_),		\
-	};								\
-	const struct usb_interface_descriptor				\
-	USB_IFACE_DESC(INTERFACE) = {					\
-		.bLength            = USB_DT_INTERFACE_SIZE,		\
-		.bDescriptorType    = USB_DT_INTERFACE,			\
-		.bInterfaceNumber   = INTERFACE,			\
-		.bAlternateSetting  = 0,				\
-		.bNumEndpoints      = 2,				\
-		.bInterfaceClass    = USB_CLASS_VENDOR_SPEC,		\
-		.bInterfaceSubClass = USB_SUBCLASS_GOOGLE_I2C,		\
-		.bInterfaceProtocol = USB_PROTOCOL_GOOGLE_I2C,		\
-		.iInterface         = 0,				\
-	};								\
-	const struct usb_endpoint_descriptor				\
-	USB_EP_DESC(INTERFACE, 0) = {					\
-		.bLength          = USB_DT_ENDPOINT_SIZE,		\
-		.bDescriptorType  = USB_DT_ENDPOINT,			\
-		.bEndpointAddress = 0x80 | ENDPOINT,			\
-		.bmAttributes     = 0x02 /* Bulk IN */,			\
-		.wMaxPacketSize   = USB_MAX_PACKET_SIZE,		\
-		.bInterval        = 10,					\
-	};								\
-	const struct usb_endpoint_descriptor				\
-	USB_EP_DESC(INTERFACE, 1) = {					\
-		.bLength          = USB_DT_ENDPOINT_SIZE,		\
-		.bDescriptorType  = USB_DT_ENDPOINT,			\
-		.bEndpointAddress = ENDPOINT,				\
-		.bmAttributes     = 0x02 /* Bulk OUT */,		\
-		.wMaxPacketSize   = USB_MAX_PACKET_SIZE,		\
-		.bInterval        = 0,					\
-	};								\
-	static void CONCAT2(NAME, _ep_tx_)   (void)			\
-		{ usb_i2c_tx(&NAME); }					\
-	static void CONCAT2(NAME, _ep_rx_)   (void)			\
-		{ usb_i2c_rx(&NAME); }					\
-	static void CONCAT2(NAME, _ep_reset_)(void)			\
-		{ usb_i2c_reset(&NAME); }				\
-	USB_DECLARE_EP(ENDPOINT,					\
-		       CONCAT2(NAME, _ep_tx_),				\
-		       CONCAT2(NAME, _ep_rx_),				\
-		       CONCAT2(NAME, _ep_reset_));			\
-	static void CONCAT2(NAME, _deferred_)(void)			\
-	{ usb_i2c_deferred(&NAME); }
-
-/*
- * Handle I2C request in a deferred callback.
- */
-void usb_i2c_deferred(struct usb_i2c_config const *config);
-
-/*
- * These functions are used by the trampoline functions defined above to
- * connect USB endpoint events with the generic USB GPIO driver.
- */
-void usb_i2c_tx(struct usb_i2c_config const *config);
-void usb_i2c_rx(struct usb_i2c_config const *config);
-void usb_i2c_reset(struct usb_i2c_config const *config);
-
-#endif /* __CROS_EC_USB_I2C_H */