Commit 712d6617 authored by Vadim Pasternak's avatar Vadim Pasternak Committed by Wolfram Sang
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i2c: mlxcpld: Allow flexible polling time setting for I2C transactions 



Allow polling time setting according to I2C frequency supported across
the system. For base frequency 400 KHz and 1 MHz set polling time is set
four times less than for system with base frequency 100KHz.

Signed-off-by: default avatarVadim Pasternak <vadimp@nvidia.com>
Signed-off-by: default avatarWolfram Sang <wsa@kernel.org>
parent 3abdc89b

drivers/i2c/busses/i2c-mlxcpld.c

+8 −4
Original line number Diff line number Diff line
@@ -73,6 +73,7 @@ struct mlxcpld_i2c_priv { 
	struct  mlxcpld_i2c_curr_xfer xfer;

	struct device *dev;

	bool smbus_block;

	int polling_time;

};



static void mlxcpld_i2c_lpc_write_buf(u8 *data, u8 len, u32 addr)
@@ -267,8 +268,8 @@ static int mlxcpld_i2c_wait_for_free(struct mlxcpld_i2c_priv *priv) 
	do {

		if (!mlxcpld_i2c_check_busy(priv))

			break;

		usleep_range(MLXCPLD_I2C_POLL_TIME / 2, MLXCPLD_I2C_POLL_TIME);

		timeout += MLXCPLD_I2C_POLL_TIME;

		usleep_range(priv->polling_time / 2, priv->polling_time);

		timeout += priv->polling_time;

	} while (timeout <= MLXCPLD_I2C_XFER_TO);



	if (timeout > MLXCPLD_I2C_XFER_TO)
@@ -288,10 +289,10 @@ static int mlxcpld_i2c_wait_for_tc(struct mlxcpld_i2c_priv *priv) 
	u8 datalen, val;



	do {

		usleep_range(MLXCPLD_I2C_POLL_TIME / 2, MLXCPLD_I2C_POLL_TIME);

		usleep_range(priv->polling_time / 2, priv->polling_time);

		if (!mlxcpld_i2c_check_status(priv, &status))

			break;

		timeout += MLXCPLD_I2C_POLL_TIME;

		timeout += priv->polling_time;

	} while (status == 0 && timeout < MLXCPLD_I2C_XFER_TO);



	switch (status) {
@@ -498,9 +499,11 @@ mlxcpld_i2c_set_frequency(struct mlxcpld_i2c_priv *priv, 
	switch ((regval & data->mask) >> data->bit) {

	case MLXCPLD_I2C_FREQ_1000KHZ:

		freq = MLXCPLD_I2C_FREQ_1000KHZ_SET;

		priv->polling_time /= 4;

		break;

	case MLXCPLD_I2C_FREQ_400KHZ:

		freq = MLXCPLD_I2C_FREQ_400KHZ_SET;

		priv->polling_time /= 4;

		break;

	default:

		return 0;
@@ -527,6 +530,7 @@ static int mlxcpld_i2c_probe(struct platform_device *pdev) 


	priv->dev = &pdev->dev;

	priv->base_addr = MLXPLAT_CPLD_LPC_I2C_BASE_ADDR;

	priv->polling_time = MLXCPLD_I2C_POLL_TIME;



	/* Set I2C bus frequency if platform data provides this info. */

	pdata = dev_get_platdata(&pdev->dev);