i2c-eeprom_slave: Add support for more eeprom models (82d51481) · Commits · 戴 / test

drivers/i2c/i2c-slave-eeprom.c

+25 −11

Original line number	Diff line number	Diff line
		@@ -11,6 +11,7 @@
		* pointer, yet implementation is deferred until the need actually arises.
		*/

		#include <linux/bitfield.h>
		#include <linux/i2c.h>
		#include <linux/init.h>
		#include <linux/module.h>
		@@ -21,12 +22,18 @@

		struct eeprom_data {
		struct bin_attribute bin;
		bool first_write;
		spinlock_t buffer_lock;
		u8 buffer_idx;
		u16 buffer_idx;
		u16 address_mask;
		u8 num_address_bytes;
		u8 idx_write_cnt;
		u8 buffer[];
		};

		#define I2C_SLAVE_BYTELEN GENMASK(15, 0)
		#define I2C_SLAVE_FLAG_ADDR16 BIT(16)
		#define I2C_SLAVE_DEVICE_MAGIC(_len, _flags) ((_flags) \| (_len))

		static int i2c_slave_eeprom_slave_cb(struct i2c_client *client,
		enum i2c_slave_event event, u8 *val)
		{
		@@ -34,12 +41,14 @@ static int i2c_slave_eeprom_slave_cb(struct i2c_client *client,

		switch (event) {
		case I2C_SLAVE_WRITE_RECEIVED:
		if (eeprom->first_write) {
		eeprom->buffer_idx = *val;
		eeprom->first_write = false;
		if (eeprom->idx_write_cnt < eeprom->num_address_bytes) {
		if (eeprom->idx_write_cnt == 0)
		eeprom->buffer_idx = 0;
		eeprom->buffer_idx = *val \| (eeprom->buffer_idx << 8);
		eeprom->idx_write_cnt++;
		} else {
		spin_lock(&eeprom->buffer_lock);
		eeprom->buffer[eeprom->buffer_idx++] = *val;
		eeprom->buffer[eeprom->buffer_idx++ & eeprom->address_mask] = *val;
		spin_unlock(&eeprom->buffer_lock);
		}
		break;
		@@ -50,7 +59,7 @@ static int i2c_slave_eeprom_slave_cb(struct i2c_client *client,
		/* fallthrough */
		case I2C_SLAVE_READ_REQUESTED:
		spin_lock(&eeprom->buffer_lock);
		*val = eeprom->buffer[eeprom->buffer_idx];
		*val = eeprom->buffer[eeprom->buffer_idx & eeprom->address_mask];
		spin_unlock(&eeprom->buffer_lock);
		/*
		* Do not increment buffer_idx here, because we don't know if
		@@ -61,7 +70,7 @@ static int i2c_slave_eeprom_slave_cb(struct i2c_client *client,

		case I2C_SLAVE_STOP:
		case I2C_SLAVE_WRITE_REQUESTED:
		eeprom->first_write = true;
		eeprom->idx_write_cnt = 0;
		break;

		default:
		@@ -105,13 +114,16 @@ static int i2c_slave_eeprom_probe(struct i2c_client *client, const struct i2c_de
		{
		struct eeprom_data *eeprom;
		int ret;
		unsigned size = id->driver_data;
		unsigned int size = FIELD_GET(I2C_SLAVE_BYTELEN, id->driver_data);
		unsigned int flag_addr16 = FIELD_GET(I2C_SLAVE_FLAG_ADDR16, id->driver_data);

		eeprom = devm_kzalloc(&client->dev, sizeof(struct eeprom_data) + size, GFP_KERNEL);
		if (!eeprom)
		return -ENOMEM;

		eeprom->first_write = true;
		eeprom->idx_write_cnt = 0;
		eeprom->num_address_bytes = flag_addr16 ? 2 : 1;
		eeprom->address_mask = size - 1;
		spin_lock_init(&eeprom->buffer_lock);
		i2c_set_clientdata(client, eeprom);

		@@ -146,7 +158,9 @@ static int i2c_slave_eeprom_remove(struct i2c_client *client)
		}

		static const struct i2c_device_id i2c_slave_eeprom_id[] = {
		{ "slave-24c02", 2048 / 8 },
		{ "slave-24c02", I2C_SLAVE_DEVICE_MAGIC(2048 / 8, 0) },
		{ "slave-24c32", I2C_SLAVE_DEVICE_MAGIC(32768 / 8, I2C_SLAVE_FLAG_ADDR16) },
		{ "slave-24c64", I2C_SLAVE_DEVICE_MAGIC(65536 / 8, I2C_SLAVE_FLAG_ADDR16) },
		{ }
		};
		MODULE_DEVICE_TABLE(i2c, i2c_slave_eeprom_id);

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