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platform/chrome: cros_ec_lpc: Add R/W helpers to LPC protocol variants

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Call common functions for read / write to prepare support for future
LPC protocol variants which use different I/O ops than inb / outb.

Signed-off-by: Shawn Nematbakhsh <shawnn@chromium.org>
Signed-off-by: Thierry Escande <thierry.escande@collabora.com>
Acked-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Benson Leung <bleung@chromium.org>
This commit is contained in:
Shawn Nematbakhsh 2017-05-16 17:46:48 +02:00 committed by Benson Leung
parent 6e4941067c
commit bce70fef72
4 changed files with 151 additions and 51 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

3
drivers/platform/chrome/Makefile
View File

@ -5,6 +5,7 @@ cros_ec_devs-objs := cros_ec_dev.o cros_ec_sysfs.o \
cros_ec_lightbar.o cros_ec_vbc.o \
cros_ec_debugfs.o
obj-$(CONFIG_CROS_EC_CHARDEV) += cros_ec_devs.o
obj-$(CONFIG_CROS_EC_LPC) += cros_ec_lpc.o
cros_ec_lpcs-objs := cros_ec_lpc.o cros_ec_lpc_reg.o
obj-$(CONFIG_CROS_EC_LPC) += cros_ec_lpcs.o
obj-$(CONFIG_CROS_EC_PROTO) += cros_ec_proto.o
obj-$(CONFIG_CROS_KBD_LED_BACKLIGHT) += cros_kbd_led_backlight.o

88
drivers/platform/chrome/cros_ec_lpc.c
View File

@ -26,19 +26,22 @@
#include <linux/io.h>
#include <linux/mfd/cros_ec.h>
#include <linux/mfd/cros_ec_commands.h>
#include <linux/mfd/cros_ec_lpc_reg.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/printk.h>
#define DRV_NAME "cros_ec_lpc"
#define DRV_NAME "cros_ec_lpcs"
static int ec_response_timed_out(void)
{
unsigned long one_second = jiffies + HZ;
u8 data;
usleep_range(200, 300);
do {
if (!(inb(EC_LPC_ADDR_HOST_CMD) & EC_LPC_STATUS_BUSY_MASK))
if (!(cros_ec_lpc_read_bytes(EC_LPC_ADDR_HOST_CMD, 1, &data) &
EC_LPC_STATUS_BUSY_MASK))
return 0;
usleep_range(100, 200);
} while (time_before(jiffies, one_second));
@ -51,21 +54,20 @@ static int cros_ec_pkt_xfer_lpc(struct cros_ec_device *ec,
{
struct ec_host_request *request;
struct ec_host_response response;
u8 sum = 0;
int i;
u8 sum;
int ret = 0;
u8 *dout;
ret = cros_ec_prepare_tx(ec, msg);
/* Write buffer */
for (i = 0; i < ret; i++)
outb(ec->dout[i], EC_LPC_ADDR_HOST_PACKET + i);
cros_ec_lpc_write_bytes(EC_LPC_ADDR_HOST_PACKET, ret, ec->dout);
request = (struct ec_host_request *)ec->dout;
/* Here we go */
outb(EC_COMMAND_PROTOCOL_3, EC_LPC_ADDR_HOST_CMD);
sum = EC_COMMAND_PROTOCOL_3;
cros_ec_lpc_write_bytes(EC_LPC_ADDR_HOST_CMD, 1, &sum);
if (ec_response_timed_out()) {
dev_warn(ec->dev, "EC responsed timed out\n");
@ -74,17 +76,15 @@ static int cros_ec_pkt_xfer_lpc(struct cros_ec_device *ec,
}
/* Check result */
msg->result = inb(EC_LPC_ADDR_HOST_DATA);
msg->result = cros_ec_lpc_read_bytes(EC_LPC_ADDR_HOST_DATA, 1, &sum);
ret = cros_ec_check_result(ec, msg);
if (ret)
goto done;
/* Read back response */
dout = (u8 *)&response;
for (i = 0; i < sizeof(response); i++) {
dout[i] = inb(EC_LPC_ADDR_HOST_PACKET + i);
sum += dout[i];
}
sum = cros_ec_lpc_read_bytes(EC_LPC_ADDR_HOST_PACKET, sizeof(response),
dout);
msg->result = response.result;
@ -97,11 +97,9 @@ static int cros_ec_pkt_xfer_lpc(struct cros_ec_device *ec,
}
/* Read response and process checksum */
for (i = 0; i < response.data_len; i++) {
msg->data[i] =
inb(EC_LPC_ADDR_HOST_PACKET + sizeof(response) + i);
sum += msg->data[i];
}
sum += cros_ec_lpc_read_bytes(EC_LPC_ADDR_HOST_PACKET +
sizeof(response), response.data_len,
msg->data);
if (sum) {
dev_err(ec->dev,
@ -121,8 +119,7 @@ static int cros_ec_cmd_xfer_lpc(struct cros_ec_device *ec,
struct cros_ec_command *msg)
{
struct ec_lpc_host_args args;
int csum;
int i;
u8 sum;
int ret = 0;
if (msg->outsize > EC_PROTO2_MAX_PARAM_SIZE ||
@ -139,24 +136,20 @@ static int cros_ec_cmd_xfer_lpc(struct cros_ec_device *ec,
args.data_size = msg->outsize;
/* Initialize checksum */
csum = msg->command + args.flags +
args.command_version + args.data_size;
sum = msg->command + args.flags + args.command_version + args.data_size;
/* Copy data and update checksum */
for (i = 0; i < msg->outsize; i++) {
outb(msg->data[i], EC_LPC_ADDR_HOST_PARAM + i);
csum += msg->data[i];
}
sum += cros_ec_lpc_write_bytes(EC_LPC_ADDR_HOST_PARAM, msg->outsize,
msg->data);
/* Finalize checksum and write args */
args.checksum = csum & 0xFF;
outb(args.flags, EC_LPC_ADDR_HOST_ARGS);
outb(args.command_version, EC_LPC_ADDR_HOST_ARGS + 1);
outb(args.data_size, EC_LPC_ADDR_HOST_ARGS + 2);
outb(args.checksum, EC_LPC_ADDR_HOST_ARGS + 3);
args.checksum = sum;
cros_ec_lpc_write_bytes(EC_LPC_ADDR_HOST_ARGS, sizeof(args),
(u8 *)&args);
/* Here we go */
outb(msg->command, EC_LPC_ADDR_HOST_CMD);
sum = msg->command;
cros_ec_lpc_write_bytes(EC_LPC_ADDR_HOST_CMD, 1, &sum);
if (ec_response_timed_out()) {
dev_warn(ec->dev, "EC responsed timed out\n");
@ -165,16 +158,14 @@ static int cros_ec_cmd_xfer_lpc(struct cros_ec_device *ec,
}
/* Check result */
msg->result = inb(EC_LPC_ADDR_HOST_DATA);
msg->result = cros_ec_lpc_read_bytes(EC_LPC_ADDR_HOST_DATA, 1, &sum);
ret = cros_ec_check_result(ec, msg);
if (ret)
goto done;
/* Read back args */
args.flags = inb(EC_LPC_ADDR_HOST_ARGS);
args.command_version = inb(EC_LPC_ADDR_HOST_ARGS + 1);
args.data_size = inb(EC_LPC_ADDR_HOST_ARGS + 2);
args.checksum = inb(EC_LPC_ADDR_HOST_ARGS + 3);
cros_ec_lpc_read_bytes(EC_LPC_ADDR_HOST_ARGS, sizeof(args),
(u8 *)&args);
if (args.data_size > msg->insize) {
dev_err(ec->dev,
@ -185,20 +176,17 @@ static int cros_ec_cmd_xfer_lpc(struct cros_ec_device *ec,
}
/* Start calculating response checksum */
csum = msg->command + args.flags +
args.command_version + args.data_size;
sum = msg->command + args.flags + args.command_version + args.data_size;
/* Read response and update checksum */
for (i = 0; i < args.data_size; i++) {
msg->data[i] = inb(EC_LPC_ADDR_HOST_PARAM + i);
csum += msg->data[i];
}
sum += cros_ec_lpc_read_bytes(EC_LPC_ADDR_HOST_PARAM, args.data_size,
msg->data);
/* Verify checksum */
if (args.checksum != (csum & 0xFF)) {
if (args.checksum != sum) {
dev_err(ec->dev,
"bad packet checksum, expected %02x, got %02x\n",
args.checksum, csum & 0xFF);
args.checksum, sum);
ret = -EBADMSG;
goto done;
}
@ -222,14 +210,13 @@ static int cros_ec_lpc_readmem(struct cros_ec_device *ec, unsigned int offset,
/* fixed length */
if (bytes) {
for (; cnt < bytes; i++, s++, cnt++)
*s = inb(EC_LPC_ADDR_MEMMAP + i);
return cnt;
cros_ec_lpc_read_bytes(EC_LPC_ADDR_MEMMAP + offset, bytes, s);
return bytes;
}
/* string */
for (; i < EC_MEMMAP_SIZE; i++, s++) {
*s = inb(EC_LPC_ADDR_MEMMAP + i);
cros_ec_lpc_read_bytes(EC_LPC_ADDR_MEMMAP + i, 1, s);
cnt++;
if (!*s)
break;
@ -242,6 +229,7 @@ static int cros_ec_lpc_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct cros_ec_device *ec_dev;
u8 buf[2];
int ret;
if (!devm_request_region(dev, EC_LPC_ADDR_MEMMAP, EC_MEMMAP_SIZE,
@ -250,8 +238,8 @@ static int cros_ec_lpc_probe(struct platform_device *pdev)
return -EBUSY;
}
if ((inb(EC_LPC_ADDR_MEMMAP + EC_MEMMAP_ID) != 'E') ||
(inb(EC_LPC_ADDR_MEMMAP + EC_MEMMAP_ID + 1) != 'C')) {
cros_ec_lpc_read_bytes(EC_LPC_ADDR_MEMMAP + EC_MEMMAP_ID, 2, buf);
if (buf[0] != 'E' || buf[1] != 'C') {
dev_err(dev, "EC ID not detected\n");
return -ENODEV;
}

64
drivers/platform/chrome/cros_ec_lpc_reg.c Normal file
View File

@ -0,0 +1,64 @@
/*
* cros_ec_lpc_reg - LPC access to the Chrome OS Embedded Controller
*
* Copyright (C) 2016 Google, Inc
*
* This software is licensed under the terms of the GNU General Public
* License version 2, as published by the Free Software Foundation, and
* may be copied, distributed, and modified under those terms.
*
* 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.
*
* This driver uses the Chrome OS EC byte-level message-based protocol for
* communicating the keyboard state (which keys are pressed) from a keyboard EC
* to the AP over some bus (such as i2c, lpc, spi). The EC does debouncing,
* but everything else (including deghosting) is done here. The main
* motivation for this is to keep the EC firmware as simple as possible, since
* it cannot be easily upgraded and EC flash/IRAM space is relatively
* expensive.
*/
#include <linux/io.h>
#include <linux/mfd/cros_ec.h>
#include <linux/mfd/cros_ec_commands.h>
static u8 lpc_read_bytes(unsigned int offset, unsigned int length, u8 *dest)
{
int i;
int sum = 0;
for (i = 0; i < length; ++i) {
dest[i] = inb(offset + i);
sum += dest[i];
}
/* Return checksum of all bytes read */
return sum;
}
static u8 lpc_write_bytes(unsigned int offset, unsigned int length, u8 *msg)
{
int i;
int sum = 0;
for (i = 0; i < length; ++i) {
outb(msg[i], offset + i);
sum += msg[i];
}
/* Return checksum of all bytes written */
return sum;
}
u8 cros_ec_lpc_read_bytes(unsigned int offset, unsigned int length, u8 *dest)
{
return lpc_read_bytes(offset, length, dest);
}
u8 cros_ec_lpc_write_bytes(unsigned int offset, unsigned int length, u8 *msg)
{
return lpc_write_bytes(offset, length, msg);
}

47
include/linux/mfd/cros_ec_lpc_reg.h Normal file
View File

@ -0,0 +1,47 @@
/*
* cros_ec_lpc_reg - LPC access to the Chrome OS Embedded Controller
*
* Copyright (C) 2016 Google, Inc
*
* This software is licensed under the terms of the GNU General Public
* License version 2, as published by the Free Software Foundation, and
* may be copied, distributed, and modified under those terms.
*
* 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.
*
* This driver uses the Chrome OS EC byte-level message-based protocol for
* communicating the keyboard state (which keys are pressed) from a keyboard EC
* to the AP over some bus (such as i2c, lpc, spi). The EC does debouncing,
* but everything else (including deghosting) is done here. The main
* motivation for this is to keep the EC firmware as simple as possible, since
* it cannot be easily upgraded and EC flash/IRAM space is relatively
* expensive.
*/
#ifndef __LINUX_MFD_CROS_EC_REG_H
#define __LINUX_MFD_CROS_EC_REG_H
/**
* cros_ec_lpc_read_bytes - Read bytes from a given LPC-mapped address.
* Returns 8-bit checksum of all bytes read.
*
* @offset: Base read address
* @length: Number of bytes to read
* @dest: Destination buffer
*/
u8 cros_ec_lpc_read_bytes(unsigned int offset, unsigned int length, u8 *dest);
/**
* cros_ec_lpc_write_bytes - Write bytes to a given LPC-mapped address.
* Returns 8-bit checksum of all bytes written.
*
* @offset: Base write address
* @length: Number of bytes to write
* @msg: Write data buffer
*/
u8 cros_ec_lpc_write_bytes(unsigned int offset, unsigned int length, u8 *msg);
#endif /* __LINUX_MFD_CROS_EC_REG_H */