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Input: cyapa - add support for smbus protocol

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This patch adds support for the Cypress APA Smbus Trackpad type,
which uses a modified register map that fits within the
limitations of the smbus protocol.

Devices that use this protocol include:
CYTRA-116001-00 - Samsung Series 5 550 Chromebook trackpad
CYTRA-103002-00 - Acer C7 Chromebook trackpad
CYTRA-101003-00 - HP Pavilion 14 Chromebook trackpad

Signed-off-by: Dudley Du <dudl@cypress.com>
Signed-off-by: Benson Leung <bleung@chromium.org>
Reviewed-by: Daniel Kurtz <djkurtz@chromium.org>
Reviewed-by: Henrik Rydberg <rydberg@euromail.se>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
This commit is contained in:
Benson Leung 2013-02-13 13:56:03 -08:00 committed by Dmitry Torokhov
parent 48064bdcd6
commit 6ddaf744c9
1 changed files with 174 additions and 5 deletions
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179
drivers/input/mouse/cyapa.c
View file

@ -208,6 +208,7 @@ struct cyapa {
char phys[32]; /* device physical location */
int irq;
bool irq_wake; /* irq wake is enabled */
bool smbus;
/* read from query data region. */
char product_id[16];
@ -229,6 +230,60 @@ struct cyapa_cmd_len {
u8 len;
};
#define CYAPA_ADAPTER_FUNC_NONE 0
#define CYAPA_ADAPTER_FUNC_I2C 1
#define CYAPA_ADAPTER_FUNC_SMBUS 2
#define CYAPA_ADAPTER_FUNC_BOTH 3
/*
* macros for SMBus communication
*/
#define SMBUS_READ 0x01
#define SMBUS_WRITE 0x00
#define SMBUS_ENCODE_IDX(cmd, idx) ((cmd) | (((idx) & 0x03) << 1))
#define SMBUS_ENCODE_RW(cmd, rw) ((cmd) | ((rw) & 0x01))
#define SMBUS_BYTE_BLOCK_CMD_MASK 0x80
#define SMBUS_GROUP_BLOCK_CMD_MASK 0x40
/* for byte read/write command */
#define CMD_RESET 0
#define CMD_POWER_MODE 1
#define CMD_DEV_STATUS 2
#define SMBUS_BYTE_CMD(cmd) (((cmd) & 0x3f) << 1)
#define CYAPA_SMBUS_RESET SMBUS_BYTE_CMD(CMD_RESET)
#define CYAPA_SMBUS_POWER_MODE SMBUS_BYTE_CMD(CMD_POWER_MODE)
#define CYAPA_SMBUS_DEV_STATUS SMBUS_BYTE_CMD(CMD_DEV_STATUS)
/* for group registers read/write command */
#define REG_GROUP_DATA 0
#define REG_GROUP_CMD 2
#define REG_GROUP_QUERY 3
#define SMBUS_GROUP_CMD(grp) (0x80 | (((grp) & 0x07) << 3))
#define CYAPA_SMBUS_GROUP_DATA SMBUS_GROUP_CMD(REG_GROUP_DATA)
#define CYAPA_SMBUS_GROUP_CMD SMBUS_GROUP_CMD(REG_GROUP_CMD)
#define CYAPA_SMBUS_GROUP_QUERY SMBUS_GROUP_CMD(REG_GROUP_QUERY)
/* for register block read/write command */
#define CMD_BL_STATUS 0
#define CMD_BL_HEAD 1
#define CMD_BL_CMD 2
#define CMD_BL_DATA 3
#define CMD_BL_ALL 4
#define CMD_BLK_PRODUCT_ID 5
#define CMD_BLK_HEAD 6
#define SMBUS_BLOCK_CMD(cmd) (0xc0 | (((cmd) & 0x1f) << 1))
/* register block read/write command in bootloader mode */
#define CYAPA_SMBUS_BL_STATUS SMBUS_BLOCK_CMD(CMD_BL_STATUS)
#define CYAPA_SMBUS_BL_HEAD SMBUS_BLOCK_CMD(CMD_BL_HEAD)
#define CYAPA_SMBUS_BL_CMD SMBUS_BLOCK_CMD(CMD_BL_CMD)
#define CYAPA_SMBUS_BL_DATA SMBUS_BLOCK_CMD(CMD_BL_DATA)
#define CYAPA_SMBUS_BL_ALL SMBUS_BLOCK_CMD(CMD_BL_ALL)
/* register block read/write command in operational mode */
#define CYAPA_SMBUS_BLK_PRODUCT_ID SMBUS_BLOCK_CMD(CMD_BLK_PRODUCT_ID)
#define CYAPA_SMBUS_BLK_HEAD SMBUS_BLOCK_CMD(CMD_BLK_HEAD)
static const struct cyapa_cmd_len cyapa_i2c_cmds[] = {
{ CYAPA_OFFSET_SOFT_RESET, 1 },
{ REG_OFFSET_COMMAND_BASE + 1, 1 },
@ -245,6 +300,22 @@ static const struct cyapa_cmd_len cyapa_i2c_cmds[] = {
{ REG_OFFSET_DATA_BASE, 32 }
};
static const struct cyapa_cmd_len cyapa_smbus_cmds[] = {
{ CYAPA_SMBUS_RESET, 1 },
{ CYAPA_SMBUS_POWER_MODE, 1 },
{ CYAPA_SMBUS_DEV_STATUS, 1 },
{ CYAPA_SMBUS_GROUP_DATA, sizeof(struct cyapa_reg_data) },
{ CYAPA_SMBUS_GROUP_CMD, 2 },
{ CYAPA_SMBUS_GROUP_QUERY, QUERY_DATA_SIZE },
{ CYAPA_SMBUS_BL_STATUS, 3 },
{ CYAPA_SMBUS_BL_HEAD, 16 },
{ CYAPA_SMBUS_BL_CMD, 16 },
{ CYAPA_SMBUS_BL_DATA, 16 },
{ CYAPA_SMBUS_BL_ALL, 32 },
{ CYAPA_SMBUS_BLK_PRODUCT_ID, PRODUCT_ID_SIZE },
{ CYAPA_SMBUS_BLK_HEAD, 16 },
};
static ssize_t cyapa_i2c_reg_read_block(struct cyapa *cyapa, u8 reg, size_t len,
u8 *values)
{
@ -257,26 +328,92 @@ static ssize_t cyapa_i2c_reg_write_block(struct cyapa *cyapa, u8 reg,
return i2c_smbus_write_i2c_block_data(cyapa->client, reg, len, values);
}
/*
* cyapa_smbus_read_block - perform smbus block read command
* @cyapa - private data structure of the driver
* @cmd - the properly encoded smbus command
* @len - expected length of smbus command result
* @values - buffer to store smbus command result
*
* Returns negative errno, else the number of bytes written.
*
* Note:
* In trackpad device, the memory block allocated for I2C register map
* is 256 bytes, so the max read block for I2C bus is 256 bytes.
*/
static ssize_t cyapa_smbus_read_block(struct cyapa *cyapa, u8 cmd, size_t len,
u8 *values)
{
ssize_t ret;
u8 index;
u8 smbus_cmd;
u8 *buf;
struct i2c_client *client = cyapa->client;
if (!(SMBUS_BYTE_BLOCK_CMD_MASK & cmd))
return -EINVAL;
if (SMBUS_GROUP_BLOCK_CMD_MASK & cmd) {
/* read specific block registers command. */
smbus_cmd = SMBUS_ENCODE_RW(cmd, SMBUS_READ);
ret = i2c_smbus_read_block_data(client, smbus_cmd, values);
goto out;
}
ret = 0;
for (index = 0; index * I2C_SMBUS_BLOCK_MAX < len; index++) {
smbus_cmd = SMBUS_ENCODE_IDX(cmd, index);
smbus_cmd = SMBUS_ENCODE_RW(smbus_cmd, SMBUS_READ);
buf = values + I2C_SMBUS_BLOCK_MAX * index;
ret = i2c_smbus_read_block_data(client, smbus_cmd, buf);
if (ret < 0)
goto out;
}
out:
return ret > 0 ? len : ret;
}
static s32 cyapa_read_byte(struct cyapa *cyapa, u8 cmd_idx)
{
u8 cmd = cyapa_i2c_cmds[cmd_idx].cmd;
u8 cmd;
if (cyapa->smbus) {
cmd = cyapa_smbus_cmds[cmd_idx].cmd;
cmd = SMBUS_ENCODE_RW(cmd, SMBUS_READ);
} else {
cmd = cyapa_i2c_cmds[cmd_idx].cmd;
}
return i2c_smbus_read_byte_data(cyapa->client, cmd);
}
static s32 cyapa_write_byte(struct cyapa *cyapa, u8 cmd_idx, u8 value)
{
u8 cmd = cyapa_i2c_cmds[cmd_idx].cmd;
u8 cmd;
if (cyapa->smbus) {
cmd = cyapa_smbus_cmds[cmd_idx].cmd;
cmd = SMBUS_ENCODE_RW(cmd, SMBUS_WRITE);
} else {
cmd = cyapa_i2c_cmds[cmd_idx].cmd;
}
return i2c_smbus_write_byte_data(cyapa->client, cmd, value);
}
static ssize_t cyapa_read_block(struct cyapa *cyapa, u8 cmd_idx, u8 *values)
{
u8 cmd = cyapa_i2c_cmds[cmd_idx].cmd;
size_t len = cyapa_i2c_cmds[cmd_idx].len;
u8 cmd;
size_t len;
return cyapa_i2c_reg_read_block(cyapa, cmd, len, values);
if (cyapa->smbus) {
cmd = cyapa_smbus_cmds[cmd_idx].cmd;
len = cyapa_smbus_cmds[cmd_idx].len;
return cyapa_smbus_read_block(cyapa, cmd, len, values);
} else {
cmd = cyapa_i2c_cmds[cmd_idx].cmd;
len = cyapa_i2c_cmds[cmd_idx].len;
return cyapa_i2c_reg_read_block(cyapa, cmd, len, values);
}
}
/*
@ -298,6 +435,15 @@ static int cyapa_get_state(struct cyapa *cyapa)
*/
ret = cyapa_i2c_reg_read_block(cyapa, BL_HEAD_OFFSET, BL_STATUS_SIZE,
status);
/*
* On smbus systems in OP mode, the i2c_reg_read will fail with
* -ETIMEDOUT. In this case, try again using the smbus equivalent
* command. This should return a BL_HEAD indicating CYAPA_STATE_OP.
*/
if (cyapa->smbus && (ret == -ETIMEDOUT || ret == -ENXIO))
ret = cyapa_read_block(cyapa, CYAPA_CMD_BL_STATUS, status);
if (ret != BL_STATUS_SIZE)
goto error;
@ -594,6 +740,19 @@ out:
return IRQ_HANDLED;
}
static u8 cyapa_check_adapter_functionality(struct i2c_client *client)
{
u8 ret = CYAPA_ADAPTER_FUNC_NONE;
if (i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
ret |= CYAPA_ADAPTER_FUNC_I2C;
if (i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_BYTE_DATA |
I2C_FUNC_SMBUS_BLOCK_DATA |
I2C_FUNC_SMBUS_I2C_BLOCK))
ret |= CYAPA_ADAPTER_FUNC_SMBUS;
return ret;
}
static int cyapa_create_input_dev(struct cyapa *cyapa)
{
struct device *dev = &cyapa->client->dev;
@ -668,9 +827,16 @@ static int cyapa_probe(struct i2c_client *client,
const struct i2c_device_id *dev_id)
{
int ret;
u8 adapter_func;
struct cyapa *cyapa;
struct device *dev = &client->dev;
adapter_func = cyapa_check_adapter_functionality(client);
if (adapter_func == CYAPA_ADAPTER_FUNC_NONE) {
dev_err(dev, "not a supported I2C/SMBus adapter\n");
return -EIO;
}
cyapa = kzalloc(sizeof(struct cyapa), GFP_KERNEL);
if (!cyapa) {
dev_err(dev, "allocate memory for cyapa failed\n");
@ -683,6 +849,9 @@ static int cyapa_probe(struct i2c_client *client,
sprintf(cyapa->phys, "i2c-%d-%04x/input0", client->adapter->nr,
client->addr);
/* i2c isn't supported, use smbus */
if (adapter_func == CYAPA_ADAPTER_FUNC_SMBUS)
cyapa->smbus = true;
cyapa->state = CYAPA_STATE_NO_DEVICE;
ret = cyapa_check_is_operational(cyapa);
if (ret) {