driver/mcdp28x0.c - chromiumos/platform/ec - Git at Google

 /* Copyright 2014 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.
  *
  * Megachips DisplayPort to HDMI protocol converter / level shifter driver.
  */

 #include "config.h"
 #include "console.h"
 #include "common.h"
 #include "ec_commands.h"
 #include "mcdp28x0.h"
 #include "queue.h"
 #include "queue_policies.h"
 #include "timer.h"
 #include "usart-stm32f0.h"
 #include "util.h"

 #define CPRINTF(format, args...) cprintf(CC_USBPD, format, ## args)

 static uint8_t mcdp_inbuf[MCDP_INBUF_MAX];

 #undef MCDP_DEBUG

 #ifdef MCDP_DEBUG
 static inline void print_buffer(uint8_t *buf, int cnt)
 {
 	int i;
 	CPRINTF("buf:");
 	for (i = 0; i < cnt; i++) {
 		if (i && !(i % 4))
 			CPRINTF("\n    ");
 		CPRINTF("[%02d]0x%02x ", i, buf[i]);
 	}
 	CPRINTF("\n");
 }
 #else
 static inline void print_buffer(uint8_t *buf, int cnt) {}
 #endif

 static struct usart_config const usart_mcdp;

 struct queue const usart_mcdp_rx_queue = QUEUE_DIRECT(MCDP_INBUF_MAX,
 						      uint8_t,
 						      usart_mcdp.producer,
 						      null_consumer);
 struct queue const usart_mcdp_tx_queue = QUEUE_DIRECT(MCDP_OUTBUF_MAX,
 						      uint8_t,
 						      null_producer,
 						      usart_mcdp.consumer);

 static struct usart_config const usart_mcdp = USART_CONFIG(CONFIG_MCDP28X0,
 							   usart_rx_interrupt,
 							   usart_tx_interrupt,
 							   115200,
 							   0,
 							   usart_mcdp_rx_queue,
 							   usart_mcdp_tx_queue);

 /**
  * Compute checksum.
  *
  * @seed initial value of checksum.
  * @msg message bytes to compute checksum on.
  * @cnt count of message bytes.
  * @return partial checksum.
  */
 static uint8_t compute_checksum(uint8_t seed, const uint8_t *msg, int cnt)
 {
 	int i;
 	uint8_t chksum = seed;

 	for (i = 0; i < cnt; i++)
 		chksum += msg[i];
 	return ~chksum + 1;
 }

 /**
  * transmit message over serial
  *
  * Packet consists of:
  *   msg[0]     == length of entire packet
  *   msg[1]     == 1st message byte (typically command)
  *   msg[cnt+1] == last message byte
  *   msg[cnt+2] == checksum
  *
  * @msg message bytes
  * @cnt count of message bytes
  * @return zero if success, error code otherwise
  */
 static int tx_serial(const uint8_t *msg, int cnt)
 {
 	uint8_t out = cnt + 2;
 	/* 1st byte (not in msg) is always cnt + 2, so seed chksum with that */
 	uint8_t chksum = compute_checksum(cnt + 2, msg, cnt);

 	if (queue_add_unit(&usart_mcdp_tx_queue, &out) != 1)
 		return MCDP_ERROR_TX_CNT;

 	if (queue_add_units(&usart_mcdp_tx_queue, msg, cnt) != cnt)
 		return MCDP_ERROR_TX_BODY;

 	print_buffer((uint8_t *)msg, cnt);

 	if (queue_add_unit(&usart_mcdp_tx_queue, &chksum) != 1)
 		return MCDP_ERROR_TX_CHKSUM;

 	return MCDP_SUCCESS;
 }

 /**
  * receive message over serial
  *
  * While definitive documentation is lacking its believed the following receive
  * packet is always true.
  *
  * Packet consists of:
  *   msg[0]     == length of entire packet
  *   msg[1]     == 1st message byte (typically command)
  *   msg[cnt+2] == last message byte
  *   msg[cnt+3] == checksum
  *
  * @msg pointer to buffer to read message into
  * @cnt count of message bytes
  * @return zero if success, error code otherwise
  */
 static int rx_serial(uint8_t *msg, int cnt)
 {
 	size_t read;
 	int retry = 2;

 	read = queue_remove_units(&usart_mcdp_rx_queue, msg, cnt);
 	while ((read < cnt) && retry) {
 		usleep(100*MSEC);
 		read += queue_remove_units(&usart_mcdp_rx_queue, msg + read,
 					   cnt - read);
 		retry--;
 	}

 	print_buffer(msg, cnt);

 	/* Some response sizes are dynamic so shrink cnt accordingly. */
 	if (cnt > msg[0])
 		cnt = msg[0];

 	if (msg[cnt-1] != compute_checksum(0, msg, cnt-1))
 		return MCDP_ERROR_CHKSUM;

 	if (read != cnt) {
 		CPRINTF("rx_serial: read bytes %d != %d cnt\n", read, cnt);
 		return MCDP_ERROR_RX_BYTES;
 	}

 	return MCDP_SUCCESS;
 }

 static int rx_serial_ack(void)
 {
 	int rv = rx_serial(mcdp_inbuf, 3);
 	if (rv)
 		return rv;

 	if (mcdp_inbuf[1] != MCDP_CMD_ACK)
 		return MCDP_ERROR_RX_ACK;

 	return rv;
 }

 void mcdp_enable(void)
 {
 	usart_init(&usart_mcdp);
 }

 void mcdp_disable(void)
 {
 	usart_shutdown(&usart_mcdp);
 }

 int mcdp_get_info(struct mcdp_info  *info)
 {
 	const uint8_t msg[2] = {MCDP_CMD_APPSTEST, 0x28};
 	int rv = tx_serial(msg, sizeof(msg));

 	if (rv)
 		return rv;

 	rv = rx_serial_ack();
 	if (rv)
 		return rv;

 	/* chksum is unreliable ... don't check */
 	rx_serial(mcdp_inbuf, MCDP_RSP_LEN(MCDP_LEN_GETINFO));

 	memcpy(info, &mcdp_inbuf[2], MCDP_LEN_GETINFO);

 	return rv;
 }

 #ifdef CONFIG_CMD_MCDP
 static int mcdp_get_dev_id(char *dev, uint8_t dev_id, int dev_cnt)
 {
 	uint8_t msg[2];
 	int rv;
 	msg[0] = MCDP_CMD_GETDEVID;
 	msg[1] = dev_id;

 	rv = tx_serial(msg, sizeof(msg));
 	if (rv)
 		return rv;

 	rv = rx_serial(mcdp_inbuf, sizeof(mcdp_inbuf));
 	if (rv)
 		return rv;

 	memcpy(dev, &mcdp_inbuf[2], mcdp_inbuf[0] - 3);
 	dev[mcdp_inbuf[0] - 3] = '\0';
 	return EC_SUCCESS;
 }

 static int mcdp_appstest(uint8_t cmd, int paramc, char **paramv)
 {
 	uint8_t msg[6];
 	char *e;
 	int i;
 	int rv = MCDP_SUCCESS;

 	/* setup any appstest params */
 	msg[0] = MCDP_CMD_APPSTESTPARAM;
 	for (i = 0; i < paramc; i++) {
 		uint32_t param = strtoi(paramv[i], &e, 10);
 		if (*e)
 			return EC_ERROR_PARAM1;
 		msg[1] = i + 1;
 		msg[2] = (param >> 24) & 0xff;
 		msg[3] = (param >> 16) & 0xff;
 		msg[4] = (param >>  8) & 0xff;
 		msg[5] = (param >>  0) & 0xff;
 		rv = tx_serial(msg, sizeof(msg));
 		if (rv)
 			return rv;

 		rv = rx_serial_ack();
 		if (rv)
 			return rv;
 	}

 	msg[0] = MCDP_CMD_APPSTEST;
 	msg[1] = cmd;
 	rv = tx_serial(msg, 2);
 	if (rv)
 		return rv;

 	rv = rx_serial_ack();
 	if (rv)
 		return rv;

 	/* magic */
 	rx_serial(mcdp_inbuf, sizeof(mcdp_inbuf));
 	rx_serial(mcdp_inbuf, sizeof(mcdp_inbuf));

 	return EC_SUCCESS;
 }

 int command_mcdp(int argc, char **argv)
 {
 	int rv = EC_SUCCESS;
 	char *e;

 	if (argc < 2)
 		return EC_ERROR_PARAM_COUNT;

 	mcdp_enable();
 	if (!strncasecmp(argv[1], "info", 4)) {
 		struct mcdp_info info;
 		rv = mcdp_get_info(&info);
 		if (!rv)
 			ccprintf("family:%04x chipid:%04x irom:%d.%d.%d "
 				 "fw:%d.%d.%d\n",
 				 MCDP_FAMILY(info.family),
 				 MCDP_CHIPID(info.chipid),
 				 info.irom.major, info.irom.minor,
 				 info.irom.build,
 				 info.fw.major, info.fw.minor, info.fw.build);
 	} else if (!strncasecmp(argv[1], "devid", 4)) {
 		uint8_t dev_id = strtoi(argv[2], &e, 10);
 		char dev[32];
 		if (*e)
 			return EC_ERROR_PARAM2;
 		else
 			rv = mcdp_get_dev_id(dev, dev_id, 32);
 		if (!rv)
 			ccprintf("devid[%d] = %s\n", dev_id, dev);
 	} else if (!strncasecmp(argv[1], "appstest", 4)) {
 		uint8_t cmd = strtoi(argv[2], &e, 10);
 		if (*e)
 			return EC_ERROR_PARAM2;
 		else
 			rv = mcdp_appstest(cmd, argc - 3, &argv[3]);
 		if (!rv)
 			ccprintf("appstest[%d] completed\n", cmd);
 	} else {
 		return EC_ERROR_PARAM1;
 	}

 	mcdp_disable();
 	if (rv)
 		ccprintf("mcdp_error:%d\n", rv);

 	return EC_SUCCESS;
 }
 DECLARE_CONSOLE_COMMAND(mcdp, command_mcdp,
 			"info|devid <id>|appstest <cmd> [<params>]",
 			"USB PD");
 #endif /* CONFIG_CMD_MCDP */
	/* Copyright 2014 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.
	*
	* Megachips DisplayPort to HDMI protocol converter / level shifter driver.
	*/

	#include "config.h"
	#include "console.h"
	#include "common.h"
	#include "ec_commands.h"
	#include "mcdp28x0.h"
	#include "queue.h"
	#include "queue_policies.h"
	#include "timer.h"
	#include "usart-stm32f0.h"
	#include "util.h"

	#define CPRINTF(format, args...) cprintf(CC_USBPD, format, ## args)

	static uint8_t mcdp_inbuf[MCDP_INBUF_MAX];

	#undef MCDP_DEBUG

	#ifdef MCDP_DEBUG
	static inline void print_buffer(uint8_t *buf, int cnt)
	{
	int i;
	CPRINTF("buf:");
	for (i = 0; i < cnt; i++) {
	if (i && !(i % 4))
	CPRINTF("\n ");
	CPRINTF("[%02d]0x%02x ", i, buf[i]);
	}
	CPRINTF("\n");
	}
	#else
	static inline void print_buffer(uint8_t *buf, int cnt) {}
	#endif

	static struct usart_config const usart_mcdp;

	struct queue const usart_mcdp_rx_queue = QUEUE_DIRECT(MCDP_INBUF_MAX,
	uint8_t,
	usart_mcdp.producer,
	null_consumer);
	struct queue const usart_mcdp_tx_queue = QUEUE_DIRECT(MCDP_OUTBUF_MAX,
	uint8_t,
	null_producer,
	usart_mcdp.consumer);

	static struct usart_config const usart_mcdp = USART_CONFIG(CONFIG_MCDP28X0,
	usart_rx_interrupt,
	usart_tx_interrupt,
	115200,
	0,
	usart_mcdp_rx_queue,
	usart_mcdp_tx_queue);

	/**
	* Compute checksum.
	*
	* @seed initial value of checksum.
	* @msg message bytes to compute checksum on.
	* @cnt count of message bytes.
	* @return partial checksum.
	*/
	static uint8_t compute_checksum(uint8_t seed, const uint8_t *msg, int cnt)
	{
	int i;
	uint8_t chksum = seed;

	for (i = 0; i < cnt; i++)
	chksum += msg[i];
	return ~chksum + 1;
	}

	/**
	* transmit message over serial
	*
	* Packet consists of:
	* msg[0] == length of entire packet
	* msg[1] == 1st message byte (typically command)
	* msg[cnt+1] == last message byte
	* msg[cnt+2] == checksum
	*
	* @msg message bytes
	* @cnt count of message bytes
	* @return zero if success, error code otherwise
	*/
	static int tx_serial(const uint8_t *msg, int cnt)
	{
	uint8_t out = cnt + 2;
	/* 1st byte (not in msg) is always cnt + 2, so seed chksum with that */
	uint8_t chksum = compute_checksum(cnt + 2, msg, cnt);

	if (queue_add_unit(&usart_mcdp_tx_queue, &out) != 1)
	return MCDP_ERROR_TX_CNT;

	if (queue_add_units(&usart_mcdp_tx_queue, msg, cnt) != cnt)
	return MCDP_ERROR_TX_BODY;

	print_buffer((uint8_t *)msg, cnt);

	if (queue_add_unit(&usart_mcdp_tx_queue, &chksum) != 1)
	return MCDP_ERROR_TX_CHKSUM;

	return MCDP_SUCCESS;
	}

	/**
	* receive message over serial
	*
	* While definitive documentation is lacking its believed the following receive
	* packet is always true.
	*
	* Packet consists of:
	* msg[0] == length of entire packet
	* msg[1] == 1st message byte (typically command)
	* msg[cnt+2] == last message byte
	* msg[cnt+3] == checksum
	*
	* @msg pointer to buffer to read message into
	* @cnt count of message bytes
	* @return zero if success, error code otherwise
	*/
	static int rx_serial(uint8_t *msg, int cnt)
	{
	size_t read;
	int retry = 2;

	read = queue_remove_units(&usart_mcdp_rx_queue, msg, cnt);
	while ((read < cnt) && retry) {
	usleep(100*MSEC);
	read += queue_remove_units(&usart_mcdp_rx_queue, msg + read,
	cnt - read);
	retry--;
	}

	print_buffer(msg, cnt);

	/* Some response sizes are dynamic so shrink cnt accordingly. */
	if (cnt > msg[0])
	cnt = msg[0];

	if (msg[cnt-1] != compute_checksum(0, msg, cnt-1))
	return MCDP_ERROR_CHKSUM;

	if (read != cnt) {
	CPRINTF("rx_serial: read bytes %d != %d cnt\n", read, cnt);
	return MCDP_ERROR_RX_BYTES;
	}

	return MCDP_SUCCESS;
	}

	static int rx_serial_ack(void)
	{
	int rv = rx_serial(mcdp_inbuf, 3);
	if (rv)
	return rv;

	if (mcdp_inbuf[1] != MCDP_CMD_ACK)
	return MCDP_ERROR_RX_ACK;

	return rv;
	}

	void mcdp_enable(void)
	{
	usart_init(&usart_mcdp);
	}

	void mcdp_disable(void)
	{
	usart_shutdown(&usart_mcdp);
	}

	int mcdp_get_info(struct mcdp_info *info)
	{
	const uint8_t msg[2] = {MCDP_CMD_APPSTEST, 0x28};
	int rv = tx_serial(msg, sizeof(msg));

	if (rv)
	return rv;

	rv = rx_serial_ack();
	if (rv)
	return rv;

	/* chksum is unreliable ... don't check */
	rx_serial(mcdp_inbuf, MCDP_RSP_LEN(MCDP_LEN_GETINFO));

	memcpy(info, &mcdp_inbuf[2], MCDP_LEN_GETINFO);

	return rv;
	}

	#ifdef CONFIG_CMD_MCDP
	static int mcdp_get_dev_id(char *dev, uint8_t dev_id, int dev_cnt)
	{
	uint8_t msg[2];
	int rv;
	msg[0] = MCDP_CMD_GETDEVID;
	msg[1] = dev_id;

	rv = tx_serial(msg, sizeof(msg));
	if (rv)
	return rv;

	rv = rx_serial(mcdp_inbuf, sizeof(mcdp_inbuf));
	if (rv)
	return rv;

	memcpy(dev, &mcdp_inbuf[2], mcdp_inbuf[0] - 3);
	dev[mcdp_inbuf[0] - 3] = '\0';
	return EC_SUCCESS;
	}

	static int mcdp_appstest(uint8_t cmd, int paramc, char **paramv)
	{
	uint8_t msg[6];
	char *e;
	int i;
	int rv = MCDP_SUCCESS;

	/* setup any appstest params */
	msg[0] = MCDP_CMD_APPSTESTPARAM;
	for (i = 0; i < paramc; i++) {
	uint32_t param = strtoi(paramv[i], &e, 10);
	if (*e)
	return EC_ERROR_PARAM1;
	msg[1] = i + 1;
	msg[2] = (param >> 24) & 0xff;
	msg[3] = (param >> 16) & 0xff;
	msg[4] = (param >> 8) & 0xff;
	msg[5] = (param >> 0) & 0xff;
	rv = tx_serial(msg, sizeof(msg));
	if (rv)
	return rv;

	rv = rx_serial_ack();
	if (rv)
	return rv;
	}

	msg[0] = MCDP_CMD_APPSTEST;
	msg[1] = cmd;
	rv = tx_serial(msg, 2);
	if (rv)
	return rv;

	rv = rx_serial_ack();
	if (rv)
	return rv;

	/* magic */
	rx_serial(mcdp_inbuf, sizeof(mcdp_inbuf));
	rx_serial(mcdp_inbuf, sizeof(mcdp_inbuf));

	return EC_SUCCESS;
	}

	int command_mcdp(int argc, char **argv)
	{
	int rv = EC_SUCCESS;
	char *e;

	if (argc < 2)
	return EC_ERROR_PARAM_COUNT;

	mcdp_enable();
	if (!strncasecmp(argv[1], "info", 4)) {
	struct mcdp_info info;
	rv = mcdp_get_info(&info);
	if (!rv)
	ccprintf("family:%04x chipid:%04x irom:%d.%d.%d "
	"fw:%d.%d.%d\n",
	MCDP_FAMILY(info.family),
	MCDP_CHIPID(info.chipid),
	info.irom.major, info.irom.minor,
	info.irom.build,
	info.fw.major, info.fw.minor, info.fw.build);
	} else if (!strncasecmp(argv[1], "devid", 4)) {
	uint8_t dev_id = strtoi(argv[2], &e, 10);
	char dev[32];
	if (*e)
	return EC_ERROR_PARAM2;
	else
	rv = mcdp_get_dev_id(dev, dev_id, 32);
	if (!rv)
	ccprintf("devid[%d] = %s\n", dev_id, dev);
	} else if (!strncasecmp(argv[1], "appstest", 4)) {
	uint8_t cmd = strtoi(argv[2], &e, 10);
	if (*e)
	return EC_ERROR_PARAM2;
	else
	rv = mcdp_appstest(cmd, argc - 3, &argv[3]);
	if (!rv)
	ccprintf("appstest[%d] completed\n", cmd);
	} else {
	return EC_ERROR_PARAM1;
	}

	mcdp_disable();
	if (rv)
	ccprintf("mcdp_error:%d\n", rv);

	return EC_SUCCESS;
	}
	DECLARE_CONSOLE_COMMAND(mcdp, command_mcdp,
	"info\|devid <id>\|appstest <cmd> [<params>]",
	"USB PD");
	#endif /* CONFIG_CMD_MCDP */