Openwrt/target/linux/layerscape/patches-5.4/808-i2c-0012-i2c-imx-correct-code-of-errata-A-010650-for-layersca.patch

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From 27ea8554c8fdcdf1d7aba5ce47630d878ce96691 Mon Sep 17 00:00:00 2001
From: Biwen Li <biwen.li@nxp.com>
Date: Thu, 24 Oct 2019 13:14:44 +0800
Subject: [PATCH] i2c: imx: correct code of errata A-010650 for layerscape
platform
- Simplify code with helper function i2c_imx_clr_al_bit
- Fix an error about clearing arbitration lost bit
- Fix an error that not set I2Cx_IBCR following by
the workaround of A-010650 (in step 5)
Reviewed-by: Clark Wang <xiaoning.wang@nxp.com>
Signed-off-by: Biwen Li <biwen.li@nxp.com>
---
drivers/i2c/busses/i2c-imx.c | 38 +++++++++++++++++++-------------------
1 file changed, 19 insertions(+), 19 deletions(-)
--- a/drivers/i2c/busses/i2c-imx.c
+++ b/drivers/i2c/busses/i2c-imx.c
@@ -503,6 +503,14 @@ static void i2c_imx_dma_free(struct imx_
dma->chan_using = NULL;
}
+/* Clear arbitration lost bit */
+static void i2c_imx_clr_al_bit(unsigned int status, struct imx_i2c_struct *i2c_imx)
+{
+ status &= ~I2SR_IAL;
+ status |= (i2c_imx->hwdata->i2sr_clr_opcode & I2SR_IAL);
+ imx_i2c_write_reg(status, i2c_imx, IMX_I2C_I2SR);
+}
+
static int i2c_imx_bus_busy(struct imx_i2c_struct *i2c_imx, int for_busy)
{
unsigned long orig_jiffies = jiffies;
@@ -515,8 +523,7 @@ static int i2c_imx_bus_busy(struct imx_i
/* check for arbitration lost */
if (temp & I2SR_IAL) {
- temp &= ~I2SR_IAL;
- imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2SR);
+ i2c_imx_clr_al_bit(temp, i2c_imx);
return -EAGAIN;
}
@@ -700,14 +707,6 @@ static void i2c_imx_clr_if_bit(unsigned
imx_i2c_write_reg(status, i2c_imx, IMX_I2C_I2SR);
}
-/* Clear arbitration lost bit */
-static void i2c_imx_clr_al_bit(unsigned int status, struct imx_i2c_struct *i2c_imx)
-{
- status &= ~I2SR_IAL;
- status |= (i2c_imx->hwdata->i2sr_clr_opcode & I2SR_IAL);
- imx_i2c_write_reg(status, i2c_imx, IMX_I2C_I2SR);
-}
-
static irqreturn_t i2c_imx_master_isr(struct imx_i2c_struct *i2c_imx)
{
unsigned int status;
@@ -1050,12 +1049,14 @@ static int i2c_imx_recovery_for_layersca
gpio_set_value(i2c_imx->gpio, 1);
/*
- * Set I2Cx_IBCR = 0h00 to generate a STOP and then
- * set I2Cx_IBCR = 0h80 to reset
+ * Set I2Cx_IBCR = 0h00 to generate a STOP
*/
- temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR);
- temp &= ~(I2CR_MSTA | I2CR_MTX);
- imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR);
+ imx_i2c_write_reg(i2c_imx->hwdata->i2cr_ien_opcode, i2c_imx, IMX_I2C_I2CR);
+
+ /*
+ * Set I2Cx_IBCR = 0h80 to reset the I2Cx controller
+ */
+ imx_i2c_write_reg(i2c_imx->hwdata->i2cr_ien_opcode | I2CR_IEN, i2c_imx, IMX_I2C_I2CR);
/* Restore the saved value of the register SCFG_RCWPMUXCR0 */
if (i2c_imx->need_set_pmuxcr == 1) {
@@ -1069,10 +1070,9 @@ static int i2c_imx_recovery_for_layersca
* I2C_IBSR[IBAL] = 1
*/
temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2SR);
- if (temp & I2SR_IAL) {
- temp &= ~I2SR_IAL;
- imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2SR);
- }
+ if (temp & I2SR_IAL)
+ i2c_imx_clr_al_bit(temp, i2c_imx);
+
return 0;
}