From 6ddaf744c9f6dd08aaec05bc9536173317b913a3 Mon Sep 17 00:00:00 2001 From: Benson Leung Date: Wed, 13 Feb 2013 13:56:03 -0800 Subject: [PATCH] Input: cyapa - add support for smbus protocol 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 Signed-off-by: Benson Leung Reviewed-by: Daniel Kurtz Reviewed-by: Henrik Rydberg Signed-off-by: Dmitry Torokhov --- drivers/input/mouse/cyapa.c | 179 +++++++++++++++++++++++++++++++++++- 1 file changed, 174 insertions(+), 5 deletions(-) diff --git a/drivers/input/mouse/cyapa.c b/drivers/input/mouse/cyapa.c index 1a14688329b..b409c3d7d4f 100644 --- a/drivers/input/mouse/cyapa.c +++ b/drivers/input/mouse/cyapa.c @@ -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) { -- 2.46.0