Commit fa4d3055 authored by Christian Eggers's avatar Christian Eggers Committed by Wolfram Sang
Browse files

i2c: imx: Fix reset of I2SR_IAL flag 



According to the "VFxxx Controller Reference Manual" (and the comment
block starting at line 97), Vybrid requires writing a one for clearing
an interrupt flag. Syncing the method for clearing I2SR_IIF in
i2c_imx_isr().

Signed-off-by: default avatarChristian Eggers <ceggers@arri.de>
Fixes: 4b775022 ("i2c: imx: add struct to hold more configurable quirks")
Reviewed-by: default avatarUwe Kleine-König <u.kleine-koenig@pengutronix.de>
Cc: stable@vger.kernel.org
Signed-off-by: default avatarWolfram Sang <wsa@kernel.org>
parent 549738f1

drivers/i2c/busses/i2c-imx.c

+15 −5
Original line number Diff line number Diff line
@@ -412,6 +412,19 @@ static void i2c_imx_dma_free(struct imx_i2c_struct *i2c_imx) 
	dma->chan_using = NULL;

}



static void i2c_imx_clear_irq(struct imx_i2c_struct *i2c_imx, unsigned int bits)

{

	unsigned int temp;



	/*

	 * i2sr_clr_opcode is the value to clear all interrupts. Here we want to

	 * clear only <bits>, so we write ~i2sr_clr_opcode with just <bits>

	 * toggled. This is required because i.MX needs W1C and Vybrid uses W0C.

	 */

	temp = ~i2c_imx->hwdata->i2sr_clr_opcode ^ bits;

	imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2SR);

}



static int i2c_imx_bus_busy(struct imx_i2c_struct *i2c_imx, int for_busy, bool atomic)

{

	unsigned long orig_jiffies = jiffies;
@@ -424,8 +437,7 @@ static int i2c_imx_bus_busy(struct imx_i2c_struct *i2c_imx, int for_busy, bool a 


		/* check for arbitration lost */

		if (temp & I2SR_IAL) {

			temp &= ~I2SR_IAL;

			imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2SR);

			i2c_imx_clear_irq(i2c_imx, I2SR_IAL);

			return -EAGAIN;

		}
@@ -623,9 +635,7 @@ static irqreturn_t i2c_imx_isr(int irq, void *dev_id) 
	if (temp & I2SR_IIF) {

		/* save status register */

		i2c_imx->i2csr = temp;

		temp &= ~I2SR_IIF;

		temp |= (i2c_imx->hwdata->i2sr_clr_opcode & I2SR_IIF);

		imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2SR);

		i2c_imx_clear_irq(i2c_imx, I2SR_IIF);

		wake_up(&i2c_imx->queue);

		return IRQ_HANDLED;

	}

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