[PATCH v5 10/10] mfd: mt6360: Merge different sub-devices I2C read/write

Gene Chen
2020-09-22T10:25:01Z

Merge different sub-devices I2C read/write functions into one Regmap,
because PMIC and LDO part need CRC bits for access protection.

Signed-off-by: Gene Chen <gene_chen@richtek.com>
---
drivers/mfd/Kconfig | 1 +
drivers/mfd/mt6360-core.c | 224 ++++++++++++++++++++++++++++++++++++++--------
2 files changed, 190 insertions(+), 35 deletions(-)

diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
index 33df083..1dfe446 100644
--- a/drivers/mfd/Kconfig
+++ b/drivers/mfd/Kconfig
@@ -913,6 +913,7 @@ config MFD_MT6360
select MFD_CORE
select REGMAP_I2C
select REGMAP_IRQ
+ select CRC8
depends on I2C
help
Say Y here to enable MT6360 PMU/PMIC/LDO functional support.
diff --git a/drivers/mfd/mt6360-core.c b/drivers/mfd/mt6360-core.c
index 075b466..2ec9559 100644
--- a/drivers/mfd/mt6360-core.c
+++ b/drivers/mfd/mt6360-core.c
@@ -62,6 +62,18 @@ struct mt6360_ddata {

#define MT6360_CRC8_POLYNOMIAL 0x7

+#define MT6360_CRC_I2C_ADDR_SIZE 1
+#define MT6360_CRC_REG_ADDR_SIZE 1
+/* prealloca read size = i2c device addr + i2c reg addr + val ... + crc8 */
+#define MT6360_ALLOC_READ_SIZE(_size) (_size + 3)
+/* prealloca write size = i2c device addr + i2c reg addr + val ... + crc8 + dummy byte */
+#define MT6360_ALLOC_WRITE_SIZE(_size) (_size + 4)
+#define MT6360_CRC_PREDATA_OFFSET (MT6360_CRC_I2C_ADDR_SIZE + MT6360_CRC_REG_ADDR_SIZE)
+#define MT6360_CRC_CRC8_SIZE 1
+#define MT6360_CRC_DUMMY_BYTE_SIZE 1
+#define MT6360_REGMAP_REG_BYTE_SIZE 2
+#define I2C_ADDR_XLATE_8BIT(_addr, _rw) (((_addr & 0x7F) << 1) + _rw)
+
/* reg 0 -> 0 ~ 7 */
#define MT6360_CHG_TREG_EVT 4
#define MT6360_CHG_AICR_EVT 5
@@ -266,12 +278,6 @@ static const struct regmap_irq_chip mt6360_irq_chip = {
.use_ack = true,
};

-static const struct regmap_config mt6360_pmu_regmap_config = {
- .reg_bits = 8,
- .val_bits = 8,
- .max_register = MT6360_PMU_MAXREG,
-};
-
static const struct resource mt6360_adc_resources[] = {
DEFINE_RES_IRQ_NAMED(MT6360_ADC_DONEI, "adc_donei"),
};
@@ -334,7 +340,7 @@ static const struct mfd_cell mt6360_devs[] = {
OF_MFD_CELL("mt6360-led", mt6360_led_resources,
NULL, 0, 0, "mediatek,mt6360-led"),
OF_MFD_CELL("mt6360-regulator", mt6360_regulator_resources,
- NULL, 0, 0, "mediatek,mt6360-regulator"),
+ NULL, 0, 0, NULL),
OF_MFD_CELL("mt6360-tcpc", NULL,
NULL, 0, 0, "mediatek,mt6360-tcpc"),
};
@@ -349,7 +355,7 @@ static int mt6360_check_vendor_info(struct mt6360_ddata *ddata)
return ret;

if ((info & CHIP_VEN_MASK) != CHIP_VEN_MT6360) {
- dev_err(&client->dev, "Device not supported\n");
+ dev_err(ddata->dev, "Device not supported\n");
return -ENODEV;
}

@@ -358,11 +364,161 @@ static int mt6360_check_vendor_info(struct mt6360_ddata *ddata)
return 0;
}

-static const unsigned short mt6360_slave_addr[MT6360_SLAVE_MAX] = {
- MT6360_PMU_SLAVEID,
+static const unsigned short mt6360_slave_addrs[MT6360_SLAVE_MAX] = {
+ MT6360_TCPC_SLAVEID,
MT6360_PMIC_SLAVEID,
MT6360_LDO_SLAVEID,
- MT6360_TCPC_SLAVEID,
+ MT6360_PMU_SLAVEID,
+};
+
+static int mt6360_xlate_pmicldo_addr(u8 *addr, int rw_size)
+{
+ /* Address is already in encoded [5:0] */
+ *addr &= MT6360_ADDRESS_MASK;
+
+ switch (rw_size) {
+ case 1:
+ *addr |= MT6360_DATA_SIZE_1_BYTE;
+ break;
+ case 2:
+ *addr |= MT6360_DATA_SIZE_2_BYTES;
+ break;
+ case 3:
+ *addr |= MT6360_DATA_SIZE_3_BYTES;
+ break;
+ case 4:
+ *addr |= MT6360_DATA_SIZE_4_BYTES;
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+static int mt6360_regmap_read(void *context, const void *reg, size_t reg_size,
+ void *val, size_t val_size)
+{
+ struct mt6360_ddata *ddata = context;
+ u8 bank = *(u8 *)reg;
+ u8 reg_addr = *(u8 *)(reg + 1);
+ struct i2c_client *i2c = ddata->i2c[bank];
+ bool crc_needed = false;
+ u8 *buf;
+ int buf_len = MT6360_ALLOC_READ_SIZE(val_size);
+ int read_size = val_size;
+ u8 crc;
+ int ret;
+
+ if (bank == MT6360_SLAVE_PMIC || bank == MT6360_SLAVE_LDO) {
+ crc_needed = true;
+ ret = mt6360_xlate_pmicldo_addr(&reg_addr, val_size);
+ if (ret < 0)
+ return ret;
+ read_size += MT6360_CRC_CRC8_SIZE;
+ }
+
+ buf = kzalloc(buf_len, GFP_KERNEL);
+ if (!buf)
+ return -ENOMEM;
+
+ buf[0] = I2C_ADDR_XLATE_8BIT(i2c->addr, I2C_SMBUS_READ);
+ buf[1] = reg_addr;
+
+ ret = i2c_smbus_read_i2c_block_data(i2c, reg_addr, read_size,
+ buf + MT6360_CRC_PREDATA_OFFSET);
+ if (ret < 0)
+ goto out;
+ else if (ret != read_size) {
+ ret = -EIO;
+ goto out;
+ }
+
+ if (crc_needed) {
+ crc = crc8(ddata->crc8_tbl, buf, val_size + MT6360_CRC_PREDATA_OFFSET, 0);
+ if (crc != buf[val_size + MT6360_CRC_PREDATA_OFFSET]) {
+ ret = -EIO;
+ goto out;
+ }
+ }
+
+ memcpy(val, buf + MT6360_CRC_PREDATA_OFFSET, val_size);
+out:
+ kfree(buf);
+ return (ret < 0) ? ret : 0;
+}
+
+static int mt6360_regmap_write(void *context, const void *val, size_t val_size)
+{
+ struct mt6360_ddata *ddata = context;
+ u8 bank = *(u8 *)val;
+ u8 reg_addr = *(u8 *)(val + 1);
+ struct i2c_client *i2c = ddata->i2c[bank];
+ bool crc_needed = false;
+ u8 *buf;
+ int buf_len = MT6360_ALLOC_WRITE_SIZE(val_size);
+ int write_size = val_size - MT6360_REGMAP_REG_BYTE_SIZE;
+ int ret;
+
+ if (bank == MT6360_SLAVE_PMIC || bank == MT6360_SLAVE_LDO) {
+ crc_needed = true;
+ ret = mt6360_xlate_pmicldo_addr(&reg_addr, val_size - MT6360_REGMAP_REG_BYTE_SIZE);
+ if (ret < 0)
+ return ret;
+ }
+
+ buf = kzalloc(buf_len, GFP_KERNEL);
+ if (!buf)
+ return -ENOMEM;
+
+ buf[0] = I2C_ADDR_XLATE_8BIT(i2c->addr, I2C_SMBUS_WRITE);
+ buf[1] = reg_addr;
+ memcpy(buf + MT6360_CRC_PREDATA_OFFSET, val + MT6360_REGMAP_REG_BYTE_SIZE, write_size);
+
+ if (crc_needed) {
+ buf[val_size] = crc8(ddata->crc8_tbl, buf, val_size, 0);
+ write_size += (MT6360_CRC_CRC8_SIZE + MT6360_CRC_DUMMY_BYTE_SIZE);
+ }
+
+ ret = i2c_smbus_write_i2c_block_data(i2c, reg_addr, write_size,
+ buf + MT6360_CRC_PREDATA_OFFSET);
+
+ kfree(buf);
+ return ret;
+}
+
+static const struct regmap_bus mt6360_regmap_bus = {
+ .read = mt6360_regmap_read,
+ .write = mt6360_regmap_write,
+
+ /* Due to PMIC and LDO CRC access size limit */
+ .max_raw_read = 4,
+ .max_raw_write = 4,
+};
+
+static bool mt6360_is_readwrite_reg(struct device *dev, unsigned int reg)
+{
+ switch (reg) {
+ case MT6360_REG_TCPCSTART ... MT6360_REG_TCPCEND:
+ fallthrough;
+ case MT6360_REG_PMICSTART ... MT6360_REG_PMICEND:
+ fallthrough;
+ case MT6360_REG_LDOSTART ... MT6360_REG_LDOEND:
+ fallthrough;
+ case MT6360_REG_PMUSTART ... MT6360_REG_PMUEND:
+ return true;
+ }
+
+ return false;
+}
+
+static const struct regmap_config mt6360_regmap_config = {
+ .reg_bits = 16,
+ .val_bits = 8,
+ .reg_format_endian = REGMAP_ENDIAN_BIG,
+ .max_register = MT6360_REG_PMUEND,
+ .writeable_reg = mt6360_is_readwrite_reg,
+ .readable_reg = mt6360_is_readwrite_reg,
};

static int mt6360_probe(struct i2c_client *client)
@@ -375,9 +531,23 @@ static int mt6360_probe(struct i2c_client *client)
return -ENOMEM;

ddata->dev = &client->dev;
- i2c_set_clientdata(client, ddata);

- ddata->regmap = devm_regmap_init_i2c(client, &mt6360_pmu_regmap_config);
+ for (i = 0; i < MT6360_SLAVE_MAX - 1; i++) {
+ ddata->i2c[i] = devm_i2c_new_dummy_device(&client->dev,
+ client->adapter,
+ mt6360_slave_addrs[i]);
+ if (IS_ERR(ddata->i2c[i])) {
+ dev_err(&client->dev,
+ "Failed to get new dummy I2C device for address 0x%x",
+ mt6360_slave_addrs[i]);
+ return PTR_ERR(ddata->i2c[i]);
+ }
+ }
+ ddata->i2c[MT6360_SLAVE_MAX - 1] = client;
+
+ crc8_populate_msb(ddata->crc8_tbl, MT6360_CRC8_POLYNOMIAL);
+ ddata->regmap = devm_regmap_init(ddata->dev, &mt6360_regmap_bus, ddata,
+ &mt6360_regmap_config);
if (IS_ERR(ddata->regmap)) {
dev_err(&client->dev, "Failed to register regmap\n");
return PTR_ERR(ddata->regmap);
@@ -387,34 +557,18 @@ static int mt6360_probe(struct i2c_client *client)
if (ret)
return ret;

- ret = devm_regmap_add_irq_chip(&client->dev, ddata->regmap, client->irq,
- 0, 0, &mt6360_irq_chip,
- &ddata->irq_data);
+ ret = devm_regmap_add_irq_chip(&client->dev, ddata->regmap, client->irq, 0, 0,
+ &mt6360_irq_chip, &ddata->irq_data);
if (ret) {
dev_err(&client->dev, "Failed to add Regmap IRQ Chip\n");
return ret;
}

- ddata->i2c[0] = client;
- for (i = 1; i < MT6360_SLAVE_MAX; i++) {
- ddata->i2c[i] = devm_i2c_new_dummy_device(&client->dev,
- client->adapter,
- mt6360_slave_addr[i]);
- if (IS_ERR(ddata->i2c[i])) {
- dev_err(&client->dev,
- "Failed to get new dummy I2C device for address 0x%x",
- mt6360_slave_addr[i]);
- return PTR_ERR(ddata->i2c[i]);
- }
- i2c_set_clientdata(ddata->i2c[i], ddata);
- }
-
- ret = devm_mfd_add_devices(&client->dev, PLATFORM_DEVID_AUTO,
- mt6360_devs, ARRAY_SIZE(mt6360_devs), NULL,
- 0, regmap_irq_get_domain(ddata->irq_data));
+ ret = devm_mfd_add_devices(&client->dev, PLATFORM_DEVID_AUTO, mt6360_devs,
+ ARRAY_SIZE(mt6360_devs), NULL, 0,
+ regmap_irq_get_domain(ddata->irq_data));
if (ret) {
- dev_err(&client->dev,
- "Failed to register subordinate devices\n");
+ dev_err(&client->dev, "Failed to register subordinate devices\n");
return ret;
}