diff mbox series

[v6,1/3] i2c: imx: Fix reset of I2SR_IAL flag

Message ID 20201009110320.20832-2-ceggers@arri.de
State Accepted
Commit 384a9565f70a876c2e78e58c5ca0bbf0547e4f6d
Headers show
Series i2c: imx: Fix handling of arbitration loss | expand

Commit Message

Christian Eggers Oct. 9, 2020, 11:03 a.m. UTC 
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@arri.de>
Fixes: 4b775022f6fd ("i2c: imx: add struct to hold more configurable quirks")
Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Acked-by: Oleksij Rempel <o.rempel@pengutronix.de>
Cc: stable@vger.kernel.org
---
 drivers/i2c/busses/i2c-imx.c | 22 ++++++++++++++++------
 1 file changed, 16 insertions(+), 6 deletions(-)

Comments

Wolfram Sang Oct. 10, 2020, 11:09 a.m. UTC | #1 
On Fri, Oct 09, 2020 at 01:03:18PM +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@arri.de>
> Fixes: 4b775022f6fd ("i2c: imx: add struct to hold more configurable quirks")
> Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
> Acked-by: Oleksij Rempel <o.rempel@pengutronix.de>
> Cc: stable@vger.kernel.org

Applied to for-next, thanks!
Wolfram Sang Dec. 2, 2020, 3:04 p.m. UTC | #2 
> > Applied to for-next, thanks!

> >

> I cannot find my patches in kernel/git/wsa/linux.git, branch "for-next".

> Did they get lost?


It seems like it :( I seem to have forgotten to push out and then
continued to to work on another computer with an older state. It is
highly embarassing but I can't find out what exactly happened. I hope I
didn't lose more patches. I am really sorry!

Pushed to for-next again.
diff mbox series

Patch

diff --git a/drivers/i2c/busses/i2c-imx.c b/drivers/i2c/busses/i2c-imx.c
index 0ab5381aa012..028f8a626410 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 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;
 		}
 
@@ -469,7 +481,7 @@  static int i2c_imx_trx_complete(struct imx_i2c_struct *i2c_imx, bool atomic)
 		 */
 		readb_poll_timeout_atomic(addr, regval, regval & I2SR_IIF, 5, 1000 + 100);
 		i2c_imx->i2csr = regval;
-		imx_i2c_write_reg(0, i2c_imx, IMX_I2C_I2SR);
+		i2c_imx_clear_irq(i2c_imx, I2SR_IIF | I2SR_IAL);
 	} else {
 		wait_event_timeout(i2c_imx->queue, i2c_imx->i2csr & I2SR_IIF, HZ / 10);
 	}
@@ -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;
 	}