The patch below does not apply to the 4.4-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@xxxxxxxxxxxxxxx>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From 384a9565f70a876c2e78e58c5ca0bbf0547e4f6d Mon Sep 17 00:00:00 2001
From: Christian Eggers <ceggers@xxxxxxx>
Date: Fri, 9 Oct 2020 13:03:18 +0200
Subject: [PATCH] i2c: imx: Fix reset of I2SR_IAL flag
MIME-Version: 1.0
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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@xxxxxxx>
Fixes: 4b775022f6fd ("i2c: imx: add struct to hold more configurable quirks")
Reviewed-by: Uwe Kleine-König <u.kleine-koenig@xxxxxxxxxxxxxx>
Acked-by: Oleksij Rempel <o.rempel@xxxxxxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Wolfram Sang <wsa@xxxxxxxxxx>
diff --git a/drivers/i2c/busses/i2c-imx.c b/drivers/i2c/busses/i2c-imx.c
index c98529c76348..39e98d216016 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;
}
