Hi Christian,
On Wed, Oct 07, 2020 at 10:45:22AM +0200, Christian Eggers wrote:
> 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: Christian Eggers <ceggers at arri.de>
> Fixes: 4b775022f6fd ("i2c: imx: add struct to hold more configurable quirks")
> Reviewed-by: Uwe Kleine-König <u.kleine-koenig at pengutronix.de>
> Cc: stable at vger.kernel.org
> ---
> drivers/i2c/busses/i2c-imx.c | 20 +++++++++++++++-----
> 1 file changed, 15 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/i2c/busses/i2c-imx.c b/drivers/i2c/busses/i2c-imx.c
> index 0ab5381aa012..cbdcab73a055 100644
> --- a/drivers/i2c/busses/i2c-imx.c
> +++ b/drivers/i2c/busses/i2c-imx.c
> @@ -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.
> + */
This comment need correction. The i.MX needs W0C and Vybrid uses W1C
> + 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;
> }
> --
Otherwise
Acked-by: Oleksij Rempel <o.rempel at pengutronix.de>
Regards,
Oleksij
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