Commit d6ceb405 authored by prashanth kumar burujukindi's avatar prashanth kumar burujukindi Committed by Andi Shyti
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i2c: microchip-corei2c: add smbus support 



Add hardware support for the SMBUS commands smbus_quick, smbus_byte,
smbus_byte_data, smbus_word_data and smbus_block_data, replacing the
fallback to software emulation

Signed-off-by: default avatarprashanth kumar burujukindi <prashanthkumar.burujukindi@microchip.com>
Signed-off-by: default avatarConor Dooley <conor.dooley@microchip.com>
Link: https://lore.kernel.org/r/20250430-preview-dormitory-85191523283d@spud


Signed-off-by: default avatarAndi Shyti <andi.shyti@kernel.org>
parent 05385900

drivers/i2c/busses/i2c-microchip-corei2c.c

+102 −0
Original line number Diff line number Diff line
@@ -76,6 +76,8 @@ 
#define CORE_I2C_FREQ		(0x14)

#define CORE_I2C_GLITCHREG	(0x18)

#define CORE_I2C_SLAVE1_ADDR	(0x1c)

#define CORE_I2C_SMBUS_MSG_WR	(0x0)

#define CORE_I2C_SMBUS_MSG_RD	(0x1)



#define PCLK_DIV_960	(CTRL_CR2)

#define PCLK_DIV_256	(0)
@@ -424,9 +426,109 @@ static u32 mchp_corei2c_func(struct i2c_adapter *adap) 
	return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;

}



static int mchp_corei2c_smbus_xfer(struct i2c_adapter *adap, u16 addr, unsigned short flags,

				   char read_write, u8 command,

				   int size, union i2c_smbus_data *data)

{

	struct i2c_msg msgs[2];

	struct mchp_corei2c_dev *idev = i2c_get_adapdata(adap);

	u8 tx_buf[I2C_SMBUS_BLOCK_MAX + 2];

	u8 rx_buf[I2C_SMBUS_BLOCK_MAX + 1];

	int num_msgs = 1;



	msgs[CORE_I2C_SMBUS_MSG_WR].addr = addr;

	msgs[CORE_I2C_SMBUS_MSG_WR].flags = 0;



	if (read_write == I2C_SMBUS_READ && size <= I2C_SMBUS_BYTE)

		msgs[CORE_I2C_SMBUS_MSG_WR].flags = I2C_M_RD;



	if (read_write == I2C_SMBUS_WRITE && size <= I2C_SMBUS_WORD_DATA)

		msgs[CORE_I2C_SMBUS_MSG_WR].len = size;



	if (read_write == I2C_SMBUS_WRITE && size > I2C_SMBUS_BYTE) {

		msgs[CORE_I2C_SMBUS_MSG_WR].buf = tx_buf;

		msgs[CORE_I2C_SMBUS_MSG_WR].buf[0] = command;

	}



	if (read_write == I2C_SMBUS_READ && size >= I2C_SMBUS_BYTE_DATA) {

		msgs[CORE_I2C_SMBUS_MSG_WR].buf = tx_buf;

		msgs[CORE_I2C_SMBUS_MSG_WR].buf[0] = command;

		msgs[CORE_I2C_SMBUS_MSG_RD].addr = addr;

		msgs[CORE_I2C_SMBUS_MSG_RD].flags = I2C_M_RD;

		num_msgs = 2;

	}



	if (read_write == I2C_SMBUS_READ && size > I2C_SMBUS_QUICK)

		msgs[CORE_I2C_SMBUS_MSG_WR].len = 1;



	switch (size) {

	case I2C_SMBUS_QUICK:

		msgs[CORE_I2C_SMBUS_MSG_WR].buf = NULL;

		return 0;

	case I2C_SMBUS_BYTE:

		if (read_write == I2C_SMBUS_WRITE)

			msgs[CORE_I2C_SMBUS_MSG_WR].buf = &command;

		else

			msgs[CORE_I2C_SMBUS_MSG_WR].buf = &data->byte;

		break;

	case I2C_SMBUS_BYTE_DATA:

		if (read_write == I2C_SMBUS_WRITE) {

			msgs[CORE_I2C_SMBUS_MSG_WR].buf[1] = data->byte;

		} else {

			msgs[CORE_I2C_SMBUS_MSG_RD].len = size - 1;

			msgs[CORE_I2C_SMBUS_MSG_RD].buf = &data->byte;

		}

		break;

	case I2C_SMBUS_WORD_DATA:

		if (read_write == I2C_SMBUS_WRITE) {

			msgs[CORE_I2C_SMBUS_MSG_WR].buf[1] = data->word & 0xFF;

			msgs[CORE_I2C_SMBUS_MSG_WR].buf[2] = (data->word >> 8) & 0xFF;

		} else {

			msgs[CORE_I2C_SMBUS_MSG_RD].len = size - 1;

			msgs[CORE_I2C_SMBUS_MSG_RD].buf = rx_buf;

		}

		break;

	case I2C_SMBUS_BLOCK_DATA:

		if (read_write == I2C_SMBUS_WRITE) {

			int data_len;



			data_len = data->block[0];

			msgs[CORE_I2C_SMBUS_MSG_WR].len = data_len + 2;

			for (int i = 0; i <= data_len; i++)

				msgs[CORE_I2C_SMBUS_MSG_WR].buf[i + 1] = data->block[i];

		} else {

			msgs[CORE_I2C_SMBUS_MSG_RD].len = I2C_SMBUS_BLOCK_MAX + 1;

			msgs[CORE_I2C_SMBUS_MSG_RD].buf = rx_buf;

		}

		break;

	default:

		return -EOPNOTSUPP;

	}



	mchp_corei2c_xfer(&idev->adapter, msgs, num_msgs);

	if (read_write == I2C_SMBUS_WRITE || size <= I2C_SMBUS_BYTE_DATA)

		return 0;



	switch (size) {

	case I2C_SMBUS_WORD_DATA:

		data->word = (rx_buf[0] | (rx_buf[1] << 8));

		break;

	case I2C_SMBUS_BLOCK_DATA:

		if (rx_buf[0] > I2C_SMBUS_BLOCK_MAX)

			rx_buf[0] = I2C_SMBUS_BLOCK_MAX;

		/* As per protocol first member of block is size of the block. */

		for (int i = 0; i <= rx_buf[0]; i++)

			data->block[i] = rx_buf[i];

		break;

	}



	return 0;

}



static const struct i2c_algorithm mchp_corei2c_algo = {

	.master_xfer = mchp_corei2c_xfer,

	.functionality = mchp_corei2c_func,

	.smbus_xfer = mchp_corei2c_smbus_xfer,

};



static int mchp_corei2c_probe(struct platform_device *pdev)