After a transfer timeout, some faulty I2C slave devices might hold down
the SDA pin. We can generate a bus clear command, hoping that the slave
might release the pins.
If the CLEAR command is not supported, we will use gpio recovery, if
available, to reset the bus.
Signed-off-by: Codrin Ciubotariu <[email protected]>
---
Changes in v4:
- moved the HW bus clear command in a recover_bus() function, to be able
to just call i2c_recover_bus() if a transfer fails;
- recovery gpios are no longer taken if HW bus clear command is
supported;
Changes in v3:
- removed unnecessary condition from info print;
- removed unneded declarations;
Changes in v2:
- called i2c_recover_bus() after an error occurs, if SDA is down;
- release gpios if recovery information is incomplete;
drivers/i2c/busses/i2c-at91-core.c | 2 ++
drivers/i2c/busses/i2c-at91-master.c | 49 ++++++++++++++++++++++++----
drivers/i2c/busses/i2c-at91.h | 7 +++-
3 files changed, 50 insertions(+), 8 deletions(-)
diff --git a/drivers/i2c/busses/i2c-at91-core.c b/drivers/i2c/busses/i2c-at91-core.c
index 3da1a8acecb5..e14edd236108 100644
--- a/drivers/i2c/busses/i2c-at91-core.c
+++ b/drivers/i2c/busses/i2c-at91-core.c
@@ -131,6 +131,7 @@ static struct at91_twi_pdata sama5d2_config = {
.has_dig_filtr = true,
.has_adv_dig_filtr = true,
.has_ana_filtr = true,
+ .has_clear_cmd = false, /* due to errata, CLEAR cmd is not working */
};
static struct at91_twi_pdata sam9x60_config = {
@@ -142,6 +143,7 @@ static struct at91_twi_pdata sam9x60_config = {
.has_dig_filtr = true,
.has_adv_dig_filtr = true,
.has_ana_filtr = true,
+ .has_clear_cmd = true,
};
static const struct of_device_id atmel_twi_dt_ids[] = {
diff --git a/drivers/i2c/busses/i2c-at91-master.c b/drivers/i2c/busses/i2c-at91-master.c
index 0aba51a7df32..776e95962ab6 100644
--- a/drivers/i2c/busses/i2c-at91-master.c
+++ b/drivers/i2c/busses/i2c-at91-master.c
@@ -480,7 +480,6 @@ static int at91_do_twi_transfer(struct at91_twi_dev *dev)
unsigned long time_left;
bool has_unre_flag = dev->pdata->has_unre_flag;
bool has_alt_cmd = dev->pdata->has_alt_cmd;
- struct i2c_bus_recovery_info *rinfo = &dev->rinfo;
/*
* WARNING: the TXCOMP bit in the Status Register is NOT a clear on
@@ -641,11 +640,12 @@ static int at91_do_twi_transfer(struct at91_twi_dev *dev)
AT91_TWI_THRCLR | AT91_TWI_LOCKCLR);
}
- if (rinfo->get_sda && !(rinfo->get_sda(&dev->adapter))) {
- dev_dbg(dev->dev,
- "SDA is down; clear bus using gpio\n");
- i2c_recover_bus(&dev->adapter);
- }
+ /*
+ * some faulty I2C slave devices might hold SDA down;
+ * we can send a bus clear command, hoping that the pins will be
+ * released
+ */
+ i2c_recover_bus(&dev->adapter);
return ret;
}
@@ -830,7 +830,7 @@ static void at91_unprepare_twi_recovery(struct i2c_adapter *adap)
pinctrl_select_state(dev->pinctrl, dev->pinctrl_pins_default);
}
-static int at91_init_twi_recovery_info(struct platform_device *pdev,
+static int at91_init_twi_recovery_gpio(struct platform_device *pdev,
struct at91_twi_dev *dev)
{
struct i2c_bus_recovery_info *rinfo = &dev->rinfo;
@@ -880,6 +880,41 @@ static int at91_init_twi_recovery_info(struct platform_device *pdev,
return 0;
}
+static int at91_twi_recover_bus_cmd(struct i2c_adapter *adap)
+{
+ struct at91_twi_dev *dev = i2c_get_adapdata(adap);
+
+ dev->transfer_status |= at91_twi_read(dev, AT91_TWI_SR);
+ if (!(dev->transfer_status & AT91_TWI_SDA)) {
+ dev_dbg(dev->dev, "SDA is down; sending bus clear command\n");
+ if (dev->use_alt_cmd) {
+ unsigned int acr;
+
+ acr = at91_twi_read(dev, AT91_TWI_ACR);
+ acr &= ~AT91_TWI_ACR_DATAL_MASK;
+ at91_twi_write(dev, AT91_TWI_ACR, acr);
+ }
+ at91_twi_write(dev, AT91_TWI_CR, AT91_TWI_CLEAR);
+ }
+
+ return 0;
+}
+
+static int at91_init_twi_recovery_info(struct platform_device *pdev,
+ struct at91_twi_dev *dev)
+{
+ struct i2c_bus_recovery_info *rinfo = &dev->rinfo;
+ bool has_clear_cmd = dev->pdata->has_clear_cmd;
+
+ if (!has_clear_cmd)
+ return at91_init_twi_recovery_gpio(pdev, dev);
+
+ rinfo->recover_bus = at91_twi_recover_bus_cmd;
+ dev->adapter.bus_recovery_info = rinfo;
+
+ return 0;
+}
+
int at91_twi_probe_master(struct platform_device *pdev,
u32 phy_addr, struct at91_twi_dev *dev)
{
diff --git a/drivers/i2c/busses/i2c-at91.h b/drivers/i2c/busses/i2c-at91.h
index f57a6cab96b4..7e7b4955ca7f 100644
--- a/drivers/i2c/busses/i2c-at91.h
+++ b/drivers/i2c/busses/i2c-at91.h
@@ -36,6 +36,7 @@
#define AT91_TWI_SVDIS BIT(5) /* Slave Transfer Disable */
#define AT91_TWI_QUICK BIT(6) /* SMBus quick command */
#define AT91_TWI_SWRST BIT(7) /* Software Reset */
+#define AT91_TWI_CLEAR BIT(15) /* Bus clear command */
#define AT91_TWI_ACMEN BIT(16) /* Alternative Command Mode Enable */
#define AT91_TWI_ACMDIS BIT(17) /* Alternative Command Mode Disable */
#define AT91_TWI_THRCLR BIT(24) /* Transmit Holding Register Clear */
@@ -69,6 +70,8 @@
#define AT91_TWI_NACK BIT(8) /* Not Acknowledged */
#define AT91_TWI_EOSACC BIT(11) /* End Of Slave Access */
#define AT91_TWI_LOCK BIT(23) /* TWI Lock due to Frame Errors */
+#define AT91_TWI_SCL BIT(24) /* TWI SCL status */
+#define AT91_TWI_SDA BIT(25) /* TWI SDA status */
#define AT91_TWI_INT_MASK \
(AT91_TWI_TXCOMP | AT91_TWI_RXRDY | AT91_TWI_TXRDY | AT91_TWI_NACK \
@@ -81,7 +84,8 @@
#define AT91_TWI_THR 0x0034 /* Transmit Holding Register */
#define AT91_TWI_ACR 0x0040 /* Alternative Command Register */
-#define AT91_TWI_ACR_DATAL(len) ((len) & 0xff)
+#define AT91_TWI_ACR_DATAL_MASK GENMASK(15, 0)
+#define AT91_TWI_ACR_DATAL(len) ((len) & AT91_TWI_ACR_DATAL_MASK)
#define AT91_TWI_ACR_DIR BIT(8)
#define AT91_TWI_FILTR 0x0044
@@ -118,6 +122,7 @@ struct at91_twi_pdata {
bool has_dig_filtr;
bool has_adv_dig_filtr;
bool has_ana_filtr;
+ bool has_clear_cmd;
struct at_dma_slave dma_slave;
};
--
2.20.1
From: Kamel Bouhara <[email protected]>
Add the i2c gpio pinctrls so the i2c bus recovery option can be enabled
Signed-off-by: Kamel Bouhara <[email protected]>
[[email protected]: removed gpio pull-ups]
Signed-off-by: Codrin Ciubotariu <[email protected]>
Acked-by: Ludovic Desroches <[email protected]>
---
Changes in v4:
- added Acked-by tag from Ludovic;
Changes in v3:
- removed gpio pull-ups;
Changes in v2:
- none;
arch/arm/boot/dts/sama5d4.dtsi | 33 ++++++++++++++++++++++++++++++---
1 file changed, 30 insertions(+), 3 deletions(-)
diff --git a/arch/arm/boot/dts/sama5d4.dtsi b/arch/arm/boot/dts/sama5d4.dtsi
index 6ab27a7b388d..26ce868096c2 100644
--- a/arch/arm/boot/dts/sama5d4.dtsi
+++ b/arch/arm/boot/dts/sama5d4.dtsi
@@ -458,8 +458,11 @@
(AT91_XDMAC_DT_MEM_IF(0) | AT91_XDMAC_DT_PER_IF(1)
| AT91_XDMAC_DT_PERID(3))>;
dma-names = "tx", "rx";
- pinctrl-names = "default";
+ pinctrl-names = "default", "gpio";
pinctrl-0 = <&pinctrl_i2c0>;
+ pinctrl-1 = <&pinctrl_i2c0_gpio>;
+ sda-gpios = <&pioA 30 GPIO_ACTIVE_HIGH>;
+ scl-gpios = <&pioA 31 GPIO_ACTIVE_HIGH>;
#address-cells = <1>;
#size-cells = <0>;
clocks = <&pmc PMC_TYPE_PERIPHERAL 32>;
@@ -477,8 +480,11 @@
(AT91_XDMAC_DT_MEM_IF(0) | AT91_XDMAC_DT_PER_IF(1)
| AT91_XDMAC_DT_PERID(5))>;
dma-names = "tx", "rx";
- pinctrl-names = "default";
+ pinctrl-names = "default", "gpio";
pinctrl-0 = <&pinctrl_i2c1>;
+ pinctrl-1 = <&pinctrl_i2c1_gpio>;
+ sda-gpios = <&pioE 29 GPIO_ACTIVE_HIGH>;
+ scl-gpios = <&pioE 30 GPIO_ACTIVE_HIGH>;
#address-cells = <1>;
#size-cells = <0>;
clocks = <&pmc PMC_TYPE_PERIPHERAL 33>;
@@ -519,8 +525,11 @@
(AT91_XDMAC_DT_MEM_IF(0) | AT91_XDMAC_DT_PER_IF(1)
| AT91_XDMAC_DT_PERID(7))>;
dma-names = "tx", "rx";
- pinctrl-names = "default";
+ pinctrl-names = "default", "gpio";
pinctrl-0 = <&pinctrl_i2c2>;
+ pinctrl-1 = <&pinctrl_i2c2_gpio>;
+ sda-gpios = <&pioB 29 GPIO_ACTIVE_HIGH>;
+ scl-gpios = <&pioB 30 GPIO_ACTIVE_HIGH>;
#address-cells = <1>;
#size-cells = <0>;
clocks = <&pmc PMC_TYPE_PERIPHERAL 34>;
@@ -1122,6 +1131,12 @@
<AT91_PIOA 30 AT91_PERIPH_A AT91_PINCTRL_NONE
AT91_PIOA 31 AT91_PERIPH_A AT91_PINCTRL_NONE>;
};
+
+ pinctrl_i2c0_gpio: i2c0-gpio {
+ atmel,pins =
+ <AT91_PIOA 30 AT91_PERIPH_GPIO AT91_PINCTRL_NONE
+ AT91_PIOA 31 AT91_PERIPH_GPIO AT91_PINCTRL_NONE>;
+ };
};
i2c1 {
@@ -1130,6 +1145,12 @@
<AT91_PIOE 29 AT91_PERIPH_C AT91_PINCTRL_NONE /* TWD1, conflicts with UART0 RX and DIBP */
AT91_PIOE 30 AT91_PERIPH_C AT91_PINCTRL_NONE>; /* TWCK1, conflicts with UART0 TX and DIBN */
};
+
+ pinctrl_i2c1_gpio: i2c1-gpio {
+ atmel,pins =
+ <AT91_PIOE 29 AT91_PERIPH_GPIO AT91_PINCTRL_NONE
+ AT91_PIOE 30 AT91_PERIPH_GPIO AT91_PINCTRL_NONE>;
+ };
};
i2c2 {
@@ -1138,6 +1159,12 @@
<AT91_PIOB 29 AT91_PERIPH_A AT91_PINCTRL_NONE /* TWD2, conflicts with RD0 and PWML1 */
AT91_PIOB 30 AT91_PERIPH_A AT91_PINCTRL_NONE>; /* TWCK2, conflicts with RF0 */
};
+
+ pinctrl_i2c2_gpio: i2c2-gpio {
+ atmel,pins =
+ <AT91_PIOB 29 AT91_PERIPH_GPIO AT91_PINCTRL_NONE
+ AT91_PIOB 30 AT91_PERIPH_GPIO AT91_PINCTRL_NONE>;
+ };
};
isi {
--
2.20.1
From: Kamel Bouhara <[email protected]>
Add the i2c gpio pinctrls to support the i2c bus recovery
Signed-off-by: Kamel Bouhara <[email protected]>
[[email protected]: removed gpio pull-ups]
Signed-off-by: Codrin Ciubotariu <[email protected]>
Acked-by: Ludovic Desroches <[email protected]>
---
Changes in v4:
- added Acked-by tag from Ludovic;
Changes in v3:
- removed gpio pull-ups;
Changes in v2:
- none;
arch/arm/boot/dts/sama5d3.dtsi | 33 ++++++++++++++++++++++++++++++---
1 file changed, 30 insertions(+), 3 deletions(-)
diff --git a/arch/arm/boot/dts/sama5d3.dtsi b/arch/arm/boot/dts/sama5d3.dtsi
index 203d40be70a5..f11b018e9173 100644
--- a/arch/arm/boot/dts/sama5d3.dtsi
+++ b/arch/arm/boot/dts/sama5d3.dtsi
@@ -159,8 +159,11 @@
dmas = <&dma0 2 AT91_DMA_CFG_PER_ID(7)>,
<&dma0 2 AT91_DMA_CFG_PER_ID(8)>;
dma-names = "tx", "rx";
- pinctrl-names = "default";
+ pinctrl-names = "default", "gpio";
pinctrl-0 = <&pinctrl_i2c0>;
+ pinctrl-1 = <&pinctrl_i2c0_gpio>;
+ sda-gpios = <&pioA 30 GPIO_ACTIVE_HIGH>;
+ scl-gpios = <&pioA 31 GPIO_ACTIVE_HIGH>;
#address-cells = <1>;
#size-cells = <0>;
clocks = <&twi0_clk>;
@@ -174,8 +177,11 @@
dmas = <&dma0 2 AT91_DMA_CFG_PER_ID(9)>,
<&dma0 2 AT91_DMA_CFG_PER_ID(10)>;
dma-names = "tx", "rx";
- pinctrl-names = "default";
+ pinctrl-names = "default", "gpio";
pinctrl-0 = <&pinctrl_i2c1>;
+ pinctrl-1 = <&pinctrl_i2c1_gpio>;
+ sda-gpios = <&pioC 26 GPIO_ACTIVE_HIGH>;
+ scl-gpios = <&pioC 27 GPIO_ACTIVE_HIGH>;
#address-cells = <1>;
#size-cells = <0>;
clocks = <&twi1_clk>;
@@ -357,8 +363,11 @@
dmas = <&dma1 2 AT91_DMA_CFG_PER_ID(11)>,
<&dma1 2 AT91_DMA_CFG_PER_ID(12)>;
dma-names = "tx", "rx";
- pinctrl-names = "default";
+ pinctrl-names = "default", "gpio";
pinctrl-0 = <&pinctrl_i2c2>;
+ pinctrl-1 = <&pinctrl_i2c2_gpio>;
+ sda-gpios = <&pioA 18 GPIO_ACTIVE_HIGH>;
+ scl-gpios = <&pioA 19 GPIO_ACTIVE_HIGH>;
#address-cells = <1>;
#size-cells = <0>;
clocks = <&twi2_clk>;
@@ -639,6 +648,12 @@
<AT91_PIOA 30 AT91_PERIPH_A AT91_PINCTRL_NONE /* PA30 periph A TWD0 pin, conflicts with URXD1, ISI_VSYNC */
AT91_PIOA 31 AT91_PERIPH_A AT91_PINCTRL_NONE>; /* PA31 periph A TWCK0 pin, conflicts with UTXD1, ISI_HSYNC */
};
+
+ pinctrl_i2c0_gpio: i2c0-gpio {
+ atmel,pins =
+ <AT91_PIOA 30 AT91_PERIPH_GPIO AT91_PINCTRL_NONE
+ AT91_PIOA 31 AT91_PERIPH_GPIO AT91_PINCTRL_NONE>;
+ };
};
i2c1 {
@@ -647,6 +662,12 @@
<AT91_PIOC 26 AT91_PERIPH_B AT91_PINCTRL_NONE /* PC26 periph B TWD1 pin, conflicts with SPI1_NPCS1, ISI_D11 */
AT91_PIOC 27 AT91_PERIPH_B AT91_PINCTRL_NONE>; /* PC27 periph B TWCK1 pin, conflicts with SPI1_NPCS2, ISI_D10 */
};
+
+ pinctrl_i2c1_gpio: i2c1-gpio {
+ atmel,pins =
+ <AT91_PIOC 26 AT91_PERIPH_GPIO AT91_PINCTRL_NONE
+ AT91_PIOC 27 AT91_PERIPH_GPIO AT91_PINCTRL_NONE>;
+ };
};
i2c2 {
@@ -655,6 +676,12 @@
<AT91_PIOA 18 AT91_PERIPH_B AT91_PINCTRL_NONE /* TWD2 pin, conflicts with LCDDAT18, ISI_D2 */
AT91_PIOA 19 AT91_PERIPH_B AT91_PINCTRL_NONE>; /* TWCK2 pin, conflicts with LCDDAT19, ISI_D3 */
};
+
+ pinctrl_i2c2_gpio: i2c2-gpio {
+ atmel,pins =
+ <AT91_PIOA 18 AT91_PERIPH_GPIO AT91_PINCTRL_NONE
+ AT91_PIOA 19 AT91_PERIPH_GPIO AT91_PINCTRL_NONE>;
+ };
};
isi {
--
2.20.1
From: Kamel Bouhara <[email protected]>
Add the i2c gpio pinctrls to support the i2c bus recovery
Signed-off-by: Kamel Bouhara <[email protected]>
[[email protected]: removed gpio pull-ups]
Signed-off-by: Codrin Ciubotariu <[email protected]>
Acked-by: Ludovic Desroches <[email protected]>
---
Changes in v4:
- added Acked-by tag from Ludovic;
Changes in v3:
- removed gpio pull-ups;
Changes in v2:
- new patch;
arch/arm/boot/dts/at91-sama5d2_ptc_ek.dts | 33 +++++++++++++++++++--
arch/arm/boot/dts/at91-sama5d2_xplained.dts | 33 +++++++++++++++++++--
2 files changed, 60 insertions(+), 6 deletions(-)
diff --git a/arch/arm/boot/dts/at91-sama5d2_ptc_ek.dts b/arch/arm/boot/dts/at91-sama5d2_ptc_ek.dts
index ba7f3e646c26..1c24ac8019ba 100644
--- a/arch/arm/boot/dts/at91-sama5d2_ptc_ek.dts
+++ b/arch/arm/boot/dts/at91-sama5d2_ptc_ek.dts
@@ -180,8 +180,11 @@
i2c0: i2c@f8028000 {
dmas = <0>, <0>;
- pinctrl-names = "default";
+ pinctrl-names = "default", "gpio";
pinctrl-0 = <&pinctrl_i2c0_default>;
+ pinctrl-1 = <&pinctrl_i2c0_gpio>;
+ sda-gpios = <&pioA PIN_PD21 GPIO_ACTIVE_HIGH>;
+ scl-gpios = <&pioA PIN_PD22 GPIO_ACTIVE_HIGH>;
status = "okay";
};
@@ -198,8 +201,11 @@
#address-cells = <1>;
#size-cells = <0>;
clocks = <&pmc PMC_TYPE_PERIPHERAL 19>;
- pinctrl-names = "default";
+ pinctrl-names = "default", "gpio";
pinctrl-0 = <&pinctrl_flx0_default>;
+ pinctrl-1 = <&pinctrl_flx0_gpio>;
+ sda-gpios = <&pioA PIN_PB28 GPIO_ACTIVE_HIGH>;
+ scl-gpios = <&pioA PIN_PB29 GPIO_ACTIVE_HIGH>;
atmel,fifo-size = <16>;
status = "okay";
};
@@ -226,8 +232,11 @@
i2c1: i2c@fc028000 {
dmas = <0>, <0>;
- pinctrl-names = "default";
+ pinctrl-names = "default", "gpio";
pinctrl-0 = <&pinctrl_i2c1_default>;
+ pinctrl-1 = <&pinctrl_i2c1_gpio>;
+ sda-gpios = <&pioA PIN_PC6 GPIO_ACTIVE_HIGH>;
+ scl-gpios = <&pioA PIN_PC7 GPIO_ACTIVE_HIGH>;
status = "okay";
at24@50 {
@@ -244,18 +253,36 @@
bias-disable;
};
+ pinctrl_flx0_gpio: flx0_gpio {
+ pinmux = <PIN_PB28__GPIO>,
+ <PIN_PB29__GPIO>;
+ bias-disable;
+ };
+
pinctrl_i2c0_default: i2c0_default {
pinmux = <PIN_PD21__TWD0>,
<PIN_PD22__TWCK0>;
bias-disable;
};
+ pinctrl_i2c0_gpio: i2c0_gpio {
+ pinmux = <PIN_PD21__GPIO>,
+ <PIN_PD22__GPIO>;
+ bias-disable;
+ };
+
pinctrl_i2c1_default: i2c1_default {
pinmux = <PIN_PC6__TWD1>,
<PIN_PC7__TWCK1>;
bias-disable;
};
+ pinctrl_i2c1_gpio: i2c1_gpio {
+ pinmux = <PIN_PC6__GPIO>,
+ <PIN_PC7__GPIO>;
+ bias-disable;
+ };
+
pinctrl_key_gpio_default: key_gpio_default {
pinmux = <PIN_PA10__GPIO>;
bias-pull-up;
diff --git a/arch/arm/boot/dts/at91-sama5d2_xplained.dts b/arch/arm/boot/dts/at91-sama5d2_xplained.dts
index 9d0a7fbea725..055ee53e4773 100644
--- a/arch/arm/boot/dts/at91-sama5d2_xplained.dts
+++ b/arch/arm/boot/dts/at91-sama5d2_xplained.dts
@@ -129,8 +129,11 @@
i2c0: i2c@f8028000 {
dmas = <0>, <0>;
- pinctrl-names = "default";
+ pinctrl-names = "default", "gpio";
pinctrl-0 = <&pinctrl_i2c0_default>;
+ pinctrl-1 = <&pinctrl_i2c0_gpio>;
+ sda-gpios = <&pioA PIN_PD21 GPIO_ACTIVE_HIGH>;
+ scl-gpios = <&pioA PIN_PD22 GPIO_ACTIVE_HIGH>;
i2c-sda-hold-time-ns = <350>;
status = "okay";
@@ -331,8 +334,11 @@
#address-cells = <1>;
#size-cells = <0>;
clocks = <&pmc PMC_TYPE_PERIPHERAL 23>;
- pinctrl-names = "default";
+ pinctrl-names = "default", "gpio";
pinctrl-0 = <&pinctrl_flx4_default>;
+ pinctrl-1 = <&pinctrl_flx4_gpio>;
+ sda-gpios = <&pioA PIN_PD12 GPIO_ACTIVE_HIGH>;
+ scl-gpios = <&pioA PIN_PD13 GPIO_ACTIVE_HIGH>;
atmel,fifo-size = <16>;
i2c-analog-filter;
i2c-digital-filter;
@@ -343,11 +349,14 @@
i2c1: i2c@fc028000 {
dmas = <0>, <0>;
- pinctrl-names = "default";
+ pinctrl-names = "default", "gpio";
pinctrl-0 = <&pinctrl_i2c1_default>;
i2c-analog-filter;
i2c-digital-filter;
i2c-digital-filter-width-ns = <35>;
+ pinctrl-1 = <&pinctrl_i2c1_gpio>;
+ sda-gpios = <&pioA PIN_PD4 GPIO_ACTIVE_HIGH>;
+ scl-gpios = <&pioA PIN_PD5 GPIO_ACTIVE_HIGH>;
status = "okay";
at24@54 {
@@ -441,18 +450,36 @@
bias-disable;
};
+ pinctrl_flx4_gpio: flx4_gpio {
+ pinmux = <PIN_PD12__GPIO>,
+ <PIN_PD13__GPIO>;
+ bias-disable;
+ };
+
pinctrl_i2c0_default: i2c0_default {
pinmux = <PIN_PD21__TWD0>,
<PIN_PD22__TWCK0>;
bias-disable;
};
+ pinctrl_i2c0_gpio: i2c0_gpio {
+ pinmux = <PIN_PD21__GPIO>,
+ <PIN_PD22__GPIO>;
+ bias-disable;
+ };
+
pinctrl_i2c1_default: i2c1_default {
pinmux = <PIN_PD4__TWD1>,
<PIN_PD5__TWCK1>;
bias-disable;
};
+ pinctrl_i2c1_gpio: i2c1_gpio {
+ pinmux = <PIN_PD4__GPIO>,
+ <PIN_PD5__GPIO>;
+ bias-disable;
+ };
+
pinctrl_i2s0_default: i2s0_default {
pinmux = <PIN_PC1__I2SC0_CK>,
<PIN_PC2__I2SC0_MCK>,
--
2.20.1
On 25/02/2020 17:50:10+0200, Codrin Ciubotariu wrote:
> From: Kamel Bouhara <[email protected]>
>
> Add the i2c gpio pinctrls to support the i2c bus recovery
>
> Signed-off-by: Kamel Bouhara <[email protected]>
> [[email protected]: removed gpio pull-ups]
> Signed-off-by: Codrin Ciubotariu <[email protected]>
> Acked-by: Ludovic Desroches <[email protected]>
> ---
>
> Changes in v4:
> - added Acked-by tag from Ludovic;
>
> Changes in v3:
> - removed gpio pull-ups;
>
> Changes in v2:
> - none;
>
> arch/arm/boot/dts/sama5d3.dtsi | 33 ++++++++++++++++++++++++++++++---
> 1 file changed, 30 insertions(+), 3 deletions(-)
>
Applied after modifying the subject, thanks.
--
Alexandre Belloni, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com
On 25/02/2020 17:50:11+0200, Codrin Ciubotariu wrote:
> From: Kamel Bouhara <[email protected]>
>
> Add the i2c gpio pinctrls so the i2c bus recovery option can be enabled
>
> Signed-off-by: Kamel Bouhara <[email protected]>
> [[email protected]: removed gpio pull-ups]
> Signed-off-by: Codrin Ciubotariu <[email protected]>
> Acked-by: Ludovic Desroches <[email protected]>
> ---
>
> Changes in v4:
> - added Acked-by tag from Ludovic;
>
> Changes in v3:
> - removed gpio pull-ups;
>
> Changes in v2:
> - none;
>
> arch/arm/boot/dts/sama5d4.dtsi | 33 ++++++++++++++++++++++++++++++---
> 1 file changed, 30 insertions(+), 3 deletions(-)
>
Applied, thanks.
--
Alexandre Belloni, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com
On 25/02/2020 17:50:12+0200, Codrin Ciubotariu wrote:
> From: Kamel Bouhara <[email protected]>
>
> Add the i2c gpio pinctrls to support the i2c bus recovery
>
> Signed-off-by: Kamel Bouhara <[email protected]>
> [[email protected]: removed gpio pull-ups]
> Signed-off-by: Codrin Ciubotariu <[email protected]>
> Acked-by: Ludovic Desroches <[email protected]>
> ---
>
> Changes in v4:
> - added Acked-by tag from Ludovic;
>
> Changes in v3:
> - removed gpio pull-ups;
>
> Changes in v2:
> - new patch;
>
> arch/arm/boot/dts/at91-sama5d2_ptc_ek.dts | 33 +++++++++++++++++++--
> arch/arm/boot/dts/at91-sama5d2_xplained.dts | 33 +++++++++++++++++++--
> 2 files changed, 60 insertions(+), 6 deletions(-)
>
Applied, thanks.
--
Alexandre Belloni, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com
On 2/25/2020 4:50 PM, Codrin Ciubotariu wrote:
> After a transfer timeout, some faulty I2C slave devices might hold down
> the SDA pin. We can generate a bus clear command, hoping that the slave
> might release the pins.
> If the CLEAR command is not supported, we will use gpio recovery, if
> available, to reset the bus.
>
> Signed-off-by: Codrin Ciubotariu <[email protected]>
Sounds good so
Acked-by: Ludovic Desroches <[email protected]>
Wolfram, you have accepted the v3 of the recovery support and requested
these changes. It has been sent as a v4, but, in fact, this patch goes
on top on v3. It could, should, have been a new patch.
Regards
Ludovic
> ---
>
> Changes in v4:
> - moved the HW bus clear command in a recover_bus() function, to be able
> to just call i2c_recover_bus() if a transfer fails;
> - recovery gpios are no longer taken if HW bus clear command is
> supported;
>
> Changes in v3:
> - removed unnecessary condition from info print;
> - removed unneded declarations;
>
> Changes in v2:
> - called i2c_recover_bus() after an error occurs, if SDA is down;
> - release gpios if recovery information is incomplete;
>
> drivers/i2c/busses/i2c-at91-core.c | 2 ++
> drivers/i2c/busses/i2c-at91-master.c | 49 ++++++++++++++++++++++++----
> drivers/i2c/busses/i2c-at91.h | 7 +++-
> 3 files changed, 50 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/i2c/busses/i2c-at91-core.c b/drivers/i2c/busses/i2c-at91-core.c
> index 3da1a8acecb5..e14edd236108 100644
> --- a/drivers/i2c/busses/i2c-at91-core.c
> +++ b/drivers/i2c/busses/i2c-at91-core.c
> @@ -131,6 +131,7 @@ static struct at91_twi_pdata sama5d2_config = {
> .has_dig_filtr = true,
> .has_adv_dig_filtr = true,
> .has_ana_filtr = true,
> + .has_clear_cmd = false, /* due to errata, CLEAR cmd is not working */
> };
>
> static struct at91_twi_pdata sam9x60_config = {
> @@ -142,6 +143,7 @@ static struct at91_twi_pdata sam9x60_config = {
> .has_dig_filtr = true,
> .has_adv_dig_filtr = true,
> .has_ana_filtr = true,
> + .has_clear_cmd = true,
> };
>
> static const struct of_device_id atmel_twi_dt_ids[] = {
> diff --git a/drivers/i2c/busses/i2c-at91-master.c b/drivers/i2c/busses/i2c-at91-master.c
> index 0aba51a7df32..776e95962ab6 100644
> --- a/drivers/i2c/busses/i2c-at91-master.c
> +++ b/drivers/i2c/busses/i2c-at91-master.c
> @@ -480,7 +480,6 @@ static int at91_do_twi_transfer(struct at91_twi_dev *dev)
> unsigned long time_left;
> bool has_unre_flag = dev->pdata->has_unre_flag;
> bool has_alt_cmd = dev->pdata->has_alt_cmd;
> - struct i2c_bus_recovery_info *rinfo = &dev->rinfo;
>
> /*
> * WARNING: the TXCOMP bit in the Status Register is NOT a clear on
> @@ -641,11 +640,12 @@ static int at91_do_twi_transfer(struct at91_twi_dev *dev)
> AT91_TWI_THRCLR | AT91_TWI_LOCKCLR);
> }
>
> - if (rinfo->get_sda && !(rinfo->get_sda(&dev->adapter))) {
> - dev_dbg(dev->dev,
> - "SDA is down; clear bus using gpio\n");
> - i2c_recover_bus(&dev->adapter);
> - }
> + /*
> + * some faulty I2C slave devices might hold SDA down;
> + * we can send a bus clear command, hoping that the pins will be
> + * released
> + */
> + i2c_recover_bus(&dev->adapter);
>
> return ret;
> }
> @@ -830,7 +830,7 @@ static void at91_unprepare_twi_recovery(struct i2c_adapter *adap)
> pinctrl_select_state(dev->pinctrl, dev->pinctrl_pins_default);
> }
>
> -static int at91_init_twi_recovery_info(struct platform_device *pdev,
> +static int at91_init_twi_recovery_gpio(struct platform_device *pdev,
> struct at91_twi_dev *dev)
> {
> struct i2c_bus_recovery_info *rinfo = &dev->rinfo;
> @@ -880,6 +880,41 @@ static int at91_init_twi_recovery_info(struct platform_device *pdev,
> return 0;
> }
>
> +static int at91_twi_recover_bus_cmd(struct i2c_adapter *adap)
> +{
> + struct at91_twi_dev *dev = i2c_get_adapdata(adap);
> +
> + dev->transfer_status |= at91_twi_read(dev, AT91_TWI_SR);
> + if (!(dev->transfer_status & AT91_TWI_SDA)) {
> + dev_dbg(dev->dev, "SDA is down; sending bus clear command\n");
> + if (dev->use_alt_cmd) {
> + unsigned int acr;
> +
> + acr = at91_twi_read(dev, AT91_TWI_ACR);
> + acr &= ~AT91_TWI_ACR_DATAL_MASK;
> + at91_twi_write(dev, AT91_TWI_ACR, acr);
> + }
> + at91_twi_write(dev, AT91_TWI_CR, AT91_TWI_CLEAR);
> + }
> +
> + return 0;
> +}
> +
> +static int at91_init_twi_recovery_info(struct platform_device *pdev,
> + struct at91_twi_dev *dev)
> +{
> + struct i2c_bus_recovery_info *rinfo = &dev->rinfo;
> + bool has_clear_cmd = dev->pdata->has_clear_cmd;
> +
> + if (!has_clear_cmd)
> + return at91_init_twi_recovery_gpio(pdev, dev);
> +
> + rinfo->recover_bus = at91_twi_recover_bus_cmd;
> + dev->adapter.bus_recovery_info = rinfo;
> +
> + return 0;
> +}
> +
> int at91_twi_probe_master(struct platform_device *pdev,
> u32 phy_addr, struct at91_twi_dev *dev)
> {
> diff --git a/drivers/i2c/busses/i2c-at91.h b/drivers/i2c/busses/i2c-at91.h
> index f57a6cab96b4..7e7b4955ca7f 100644
> --- a/drivers/i2c/busses/i2c-at91.h
> +++ b/drivers/i2c/busses/i2c-at91.h
> @@ -36,6 +36,7 @@
> #define AT91_TWI_SVDIS BIT(5) /* Slave Transfer Disable */
> #define AT91_TWI_QUICK BIT(6) /* SMBus quick command */
> #define AT91_TWI_SWRST BIT(7) /* Software Reset */
> +#define AT91_TWI_CLEAR BIT(15) /* Bus clear command */
> #define AT91_TWI_ACMEN BIT(16) /* Alternative Command Mode Enable */
> #define AT91_TWI_ACMDIS BIT(17) /* Alternative Command Mode Disable */
> #define AT91_TWI_THRCLR BIT(24) /* Transmit Holding Register Clear */
> @@ -69,6 +70,8 @@
> #define AT91_TWI_NACK BIT(8) /* Not Acknowledged */
> #define AT91_TWI_EOSACC BIT(11) /* End Of Slave Access */
> #define AT91_TWI_LOCK BIT(23) /* TWI Lock due to Frame Errors */
> +#define AT91_TWI_SCL BIT(24) /* TWI SCL status */
> +#define AT91_TWI_SDA BIT(25) /* TWI SDA status */
>
> #define AT91_TWI_INT_MASK \
> (AT91_TWI_TXCOMP | AT91_TWI_RXRDY | AT91_TWI_TXRDY | AT91_TWI_NACK \
> @@ -81,7 +84,8 @@
> #define AT91_TWI_THR 0x0034 /* Transmit Holding Register */
>
> #define AT91_TWI_ACR 0x0040 /* Alternative Command Register */
> -#define AT91_TWI_ACR_DATAL(len) ((len) & 0xff)
> +#define AT91_TWI_ACR_DATAL_MASK GENMASK(15, 0)
> +#define AT91_TWI_ACR_DATAL(len) ((len) & AT91_TWI_ACR_DATAL_MASK)
> #define AT91_TWI_ACR_DIR BIT(8)
>
> #define AT91_TWI_FILTR 0x0044
> @@ -118,6 +122,7 @@ struct at91_twi_pdata {
> bool has_dig_filtr;
> bool has_adv_dig_filtr;
> bool has_ana_filtr;
> + bool has_clear_cmd;
> struct at_dma_slave dma_slave;
> };
>
>
On 30.03.2020 00:13, Ludovic Desroches - M43218 wrote:
> On 2/25/2020 4:50 PM, Codrin Ciubotariu wrote:
>> After a transfer timeout, some faulty I2C slave devices might hold down
>> the SDA pin. We can generate a bus clear command, hoping that the slave
>> might release the pins.
>> If the CLEAR command is not supported, we will use gpio recovery, if
>> available, to reset the bus.
>>
>> Signed-off-by: Codrin Ciubotariu <[email protected]>
>
> Sounds good so
> Acked-by: Ludovic Desroches <[email protected]>
>
> Wolfram, you have accepted the v3 of the recovery support and requested
> these changes. It has been sent as a v4, but, in fact, this patch goes
> on top on v3. It could, should, have been a new patch.
>
> Regards
>
> Ludovic
Hello, any updates on this patch? Do you want me to change anything?
Best regards,
Codrin
>
>> ---
>>
>> Changes in v4:
>> - moved the HW bus clear command in a recover_bus() function, to be able
>> to just call i2c_recover_bus() if a transfer fails;
>> - recovery gpios are no longer taken if HW bus clear command is
>> supported;
>>
>> Changes in v3:
>> - removed unnecessary condition from info print;
>> - removed unneded declarations;
>>
>> Changes in v2:
>> - called i2c_recover_bus() after an error occurs, if SDA is down;
>> - release gpios if recovery information is incomplete;
>>
>> drivers/i2c/busses/i2c-at91-core.c | 2 ++
>> drivers/i2c/busses/i2c-at91-master.c | 49 ++++++++++++++++++++++++----
>> drivers/i2c/busses/i2c-at91.h | 7 +++-
>> 3 files changed, 50 insertions(+), 8 deletions(-)
>>
>> diff --git a/drivers/i2c/busses/i2c-at91-core.c b/drivers/i2c/busses/i2c-at91-core.c
>> index 3da1a8acecb5..e14edd236108 100644
>> --- a/drivers/i2c/busses/i2c-at91-core.c
>> +++ b/drivers/i2c/busses/i2c-at91-core.c
>> @@ -131,6 +131,7 @@ static struct at91_twi_pdata sama5d2_config = {
>> .has_dig_filtr = true,
>> .has_adv_dig_filtr = true,
>> .has_ana_filtr = true,
>> + .has_clear_cmd = false, /* due to errata, CLEAR cmd is not working */
>> };
>>
>> static struct at91_twi_pdata sam9x60_config = {
>> @@ -142,6 +143,7 @@ static struct at91_twi_pdata sam9x60_config = {
>> .has_dig_filtr = true,
>> .has_adv_dig_filtr = true,
>> .has_ana_filtr = true,
>> + .has_clear_cmd = true,
>> };
>>
>> static const struct of_device_id atmel_twi_dt_ids[] = {
>> diff --git a/drivers/i2c/busses/i2c-at91-master.c b/drivers/i2c/busses/i2c-at91-master.c
>> index 0aba51a7df32..776e95962ab6 100644
>> --- a/drivers/i2c/busses/i2c-at91-master.c
>> +++ b/drivers/i2c/busses/i2c-at91-master.c
>> @@ -480,7 +480,6 @@ static int at91_do_twi_transfer(struct at91_twi_dev *dev)
>> unsigned long time_left;
>> bool has_unre_flag = dev->pdata->has_unre_flag;
>> bool has_alt_cmd = dev->pdata->has_alt_cmd;
>> - struct i2c_bus_recovery_info *rinfo = &dev->rinfo;
>>
>> /*
>> * WARNING: the TXCOMP bit in the Status Register is NOT a clear on
>> @@ -641,11 +640,12 @@ static int at91_do_twi_transfer(struct at91_twi_dev *dev)
>> AT91_TWI_THRCLR | AT91_TWI_LOCKCLR);
>> }
>>
>> - if (rinfo->get_sda && !(rinfo->get_sda(&dev->adapter))) {
>> - dev_dbg(dev->dev,
>> - "SDA is down; clear bus using gpio\n");
>> - i2c_recover_bus(&dev->adapter);
>> - }
>> + /*
>> + * some faulty I2C slave devices might hold SDA down;
>> + * we can send a bus clear command, hoping that the pins will be
>> + * released
>> + */
>> + i2c_recover_bus(&dev->adapter);
>>
>> return ret;
>> }
>> @@ -830,7 +830,7 @@ static void at91_unprepare_twi_recovery(struct i2c_adapter *adap)
>> pinctrl_select_state(dev->pinctrl, dev->pinctrl_pins_default);
>> }
>>
>> -static int at91_init_twi_recovery_info(struct platform_device *pdev,
>> +static int at91_init_twi_recovery_gpio(struct platform_device *pdev,
>> struct at91_twi_dev *dev)
>> {
>> struct i2c_bus_recovery_info *rinfo = &dev->rinfo;
>> @@ -880,6 +880,41 @@ static int at91_init_twi_recovery_info(struct platform_device *pdev,
>> return 0;
>> }
>>
>> +static int at91_twi_recover_bus_cmd(struct i2c_adapter *adap)
>> +{
>> + struct at91_twi_dev *dev = i2c_get_adapdata(adap);
>> +
>> + dev->transfer_status |= at91_twi_read(dev, AT91_TWI_SR);
>> + if (!(dev->transfer_status & AT91_TWI_SDA)) {
>> + dev_dbg(dev->dev, "SDA is down; sending bus clear command\n");
>> + if (dev->use_alt_cmd) {
>> + unsigned int acr;
>> +
>> + acr = at91_twi_read(dev, AT91_TWI_ACR);
>> + acr &= ~AT91_TWI_ACR_DATAL_MASK;
>> + at91_twi_write(dev, AT91_TWI_ACR, acr);
>> + }
>> + at91_twi_write(dev, AT91_TWI_CR, AT91_TWI_CLEAR);
>> + }
>> +
>> + return 0;
>> +}
>> +
>> +static int at91_init_twi_recovery_info(struct platform_device *pdev,
>> + struct at91_twi_dev *dev)
>> +{
>> + struct i2c_bus_recovery_info *rinfo = &dev->rinfo;
>> + bool has_clear_cmd = dev->pdata->has_clear_cmd;
>> +
>> + if (!has_clear_cmd)
>> + return at91_init_twi_recovery_gpio(pdev, dev);
>> +
>> + rinfo->recover_bus = at91_twi_recover_bus_cmd;
>> + dev->adapter.bus_recovery_info = rinfo;
>> +
>> + return 0;
>> +}
>> +
>> int at91_twi_probe_master(struct platform_device *pdev,
>> u32 phy_addr, struct at91_twi_dev *dev)
>> {
>> diff --git a/drivers/i2c/busses/i2c-at91.h b/drivers/i2c/busses/i2c-at91.h
>> index f57a6cab96b4..7e7b4955ca7f 100644
>> --- a/drivers/i2c/busses/i2c-at91.h
>> +++ b/drivers/i2c/busses/i2c-at91.h
>> @@ -36,6 +36,7 @@
>> #define AT91_TWI_SVDIS BIT(5) /* Slave Transfer Disable */
>> #define AT91_TWI_QUICK BIT(6) /* SMBus quick command */
>> #define AT91_TWI_SWRST BIT(7) /* Software Reset */
>> +#define AT91_TWI_CLEAR BIT(15) /* Bus clear command */
>> #define AT91_TWI_ACMEN BIT(16) /* Alternative Command Mode Enable */
>> #define AT91_TWI_ACMDIS BIT(17) /* Alternative Command Mode Disable */
>> #define AT91_TWI_THRCLR BIT(24) /* Transmit Holding Register Clear */
>> @@ -69,6 +70,8 @@
>> #define AT91_TWI_NACK BIT(8) /* Not Acknowledged */
>> #define AT91_TWI_EOSACC BIT(11) /* End Of Slave Access */
>> #define AT91_TWI_LOCK BIT(23) /* TWI Lock due to Frame Errors */
>> +#define AT91_TWI_SCL BIT(24) /* TWI SCL status */
>> +#define AT91_TWI_SDA BIT(25) /* TWI SDA status */
>>
>> #define AT91_TWI_INT_MASK \
>> (AT91_TWI_TXCOMP | AT91_TWI_RXRDY | AT91_TWI_TXRDY | AT91_TWI_NACK \
>> @@ -81,7 +84,8 @@
>> #define AT91_TWI_THR 0x0034 /* Transmit Holding Register */
>>
>> #define AT91_TWI_ACR 0x0040 /* Alternative Command Register */
>> -#define AT91_TWI_ACR_DATAL(len) ((len) & 0xff)
>> +#define AT91_TWI_ACR_DATAL_MASK GENMASK(15, 0)
>> +#define AT91_TWI_ACR_DATAL(len) ((len) & AT91_TWI_ACR_DATAL_MASK)
>> #define AT91_TWI_ACR_DIR BIT(8)
>>
>> #define AT91_TWI_FILTR 0x0044
>> @@ -118,6 +122,7 @@ struct at91_twi_pdata {
>> bool has_dig_filtr;
>> bool has_adv_dig_filtr;
>> bool has_ana_filtr;
>> + bool has_clear_cmd;
>> struct at_dma_slave dma_slave;
>> };
>>
>>
>
On Tue, Feb 25, 2020 at 05:50:09PM +0200, Codrin Ciubotariu wrote:
> After a transfer timeout, some faulty I2C slave devices might hold down
> the SDA pin. We can generate a bus clear command, hoping that the slave
> might release the pins.
> If the CLEAR command is not supported, we will use gpio recovery, if
> available, to reset the bus.
>
> Signed-off-by: Codrin Ciubotariu <[email protected]>
Applied to for-next, thanks!