diff mbox

[v7,3/6] mfd: at91-usart: added mfd driver for usart

Message ID 20180613163621.23995-4-radu.pirea@microchip.com (mailing list archive)
State New, archived
Headers show

Commit Message

Radu Pirea June 13, 2018, 4:36 p.m. UTC
This mfd driver is just a wrapper over atmel_serial driver and
spi-at91-usart driver. Selection of one of the drivers is based on a
property from device tree. If the property is not specified, the default
driver is atmel_serial.

Signed-off-by: Radu Pirea <radu.pirea@microchip.com>
Acked-by: Rob Herring <robh@kernel.org>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Acked-for-MFD-by: Lee Jones <lee.jones@linaro.org>
---
 drivers/mfd/Kconfig      |  9 ++++++
 drivers/mfd/Makefile     |  1 +
 drivers/mfd/at91-usart.c | 69 ++++++++++++++++++++++++++++++++++++++++
 3 files changed, 79 insertions(+)
 create mode 100644 drivers/mfd/at91-usart.c

Comments

Ludovic Desroches June 14, 2018, 7:58 a.m. UTC | #1
On Wed, Jun 13, 2018 at 07:36:18PM +0300, Radu Pirea wrote:
> This mfd driver is just a wrapper over atmel_serial driver and
> spi-at91-usart driver. Selection of one of the drivers is based on a
> property from device tree. If the property is not specified, the default
> driver is atmel_serial.
> 
> Signed-off-by: Radu Pirea <radu.pirea@microchip.com>
> Acked-by: Rob Herring <robh@kernel.org>
> Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
> Acked-for-MFD-by: Lee Jones <lee.jones@linaro.org>
> ---
>  drivers/mfd/Kconfig      |  9 ++++++
>  drivers/mfd/Makefile     |  1 +
>  drivers/mfd/at91-usart.c | 69 ++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 79 insertions(+)
>  create mode 100644 drivers/mfd/at91-usart.c
> 
> diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
> index b860eb5aa194..a886672b960d 100644
> --- a/drivers/mfd/Kconfig
> +++ b/drivers/mfd/Kconfig
> @@ -99,6 +99,15 @@ config MFD_AAT2870_CORE
>  	  additional drivers must be enabled in order to use the
>  	  functionality of the device.
>  
> +config MFD_AT91_USART
> +	tristate "AT91 USART Driver"
> +	select MFD_CORE
> +	help
> +	  Select this to get support for AT91 USART IP. This is a wrapper
> +	  over at91-usart-serial driver and usart-spi-driver. Only one function
> +	  can be used at a time. The choice is done at boot time by the probe
> +	  function of this MFD driver according to a device tree property.
> +
>  config MFD_ATMEL_FLEXCOM
>  	tristate "Atmel Flexcom (Flexible Serial Communication Unit)"
>  	select MFD_CORE
> diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
> index d9d2cf0d32ef..db1332aa96db 100644
> --- a/drivers/mfd/Makefile
> +++ b/drivers/mfd/Makefile
> @@ -185,6 +185,7 @@ obj-$(CONFIG_MFD_SPMI_PMIC)	+= qcom-spmi-pmic.o
>  obj-$(CONFIG_TPS65911_COMPARATOR)	+= tps65911-comparator.o
>  obj-$(CONFIG_MFD_TPS65090)	+= tps65090.o
>  obj-$(CONFIG_MFD_AAT2870_CORE)	+= aat2870-core.o
> +obj-$(CONFIG_MFD_AT91_USART)	+= at91-usart.o
>  obj-$(CONFIG_MFD_ATMEL_FLEXCOM)	+= atmel-flexcom.o
>  obj-$(CONFIG_MFD_ATMEL_HLCDC)	+= atmel-hlcdc.o
>  obj-$(CONFIG_MFD_ATMEL_SMC)	+= atmel-smc.o
> diff --git a/drivers/mfd/at91-usart.c b/drivers/mfd/at91-usart.c
> new file mode 100644
> index 000000000000..3014ce532644
> --- /dev/null
> +++ b/drivers/mfd/at91-usart.c
> @@ -0,0 +1,69 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Driver for AT91 USART
> + *
> + * Copyright (C) 2018 Microchip Technology
> + *
> + * Author: Radu Pirea <radu.pirea@microchip.com>
> + *
> + */
> +
> +#include <dt-bindings/mfd/at91-usart.h>
> +
> +#include <linux/module.h>
> +#include <linux/mfd/core.h>
> +#include <linux/property.h>
> +
> +static struct mfd_cell at91_usart_spi_subdev = {
> +		.name = "at91_usart_spi",
> +		.of_compatible = "microchip,at91sam9g45-usart-spi",
> +	};
> +
> +static struct mfd_cell at91_usart_serial_subdev = {
> +		.name = "atmel_usart_serial",
> +		.of_compatible = "atmel,at91rm9200-usart-serial",
> +	};
> +
> +static int at91_usart_mode_probe(struct platform_device *pdev)
> +{
> +	struct mfd_cell cell;
> +	u32 opmode = AT91_USART_MODE_SERIAL;
> +
> +	device_property_read_u32(&pdev->dev, "atmel,usart-mode", &opmode);
> +
> +	switch (opmode) {
> +	case AT91_USART_MODE_SPI:
> +		cell = at91_usart_spi_subdev;
> +		break;
> +	case AT91_USART_MODE_SERIAL:
> +		cell = at91_usart_serial_subdev;
> +		break;
> +	default:
> +		break;

If there is an invalid opmode from the DT, you will pass a non initialized cell
to mfd_add_device().

Regards

Ludovic

> +	}
> +
> +	return devm_mfd_add_devices(&pdev->dev, PLATFORM_DEVID_AUTO, &cell, 1,
> +			      NULL, 0, NULL);
> +}
> +
> +static const struct of_device_id at91_usart_mode_of_match[] = {
> +	{ .compatible = "atmel,at91rm9200-usart" },
> +	{ .compatible = "atmel,at91sam9260-usart" },
> +	{ /* sentinel */ }
> +};
> +
> +MODULE_DEVICE_TABLE(of, at91_flexcom_of_match);
> +
> +static struct platform_driver at91_usart_mfd = {
> +	.probe	= at91_usart_mode_probe,
> +	.driver	= {
> +		.name		= "at91_usart_mode",
> +		.of_match_table	= at91_usart_mode_of_match,
> +	},
> +};
> +
> +module_platform_driver(at91_usart_mfd);
> +
> +MODULE_AUTHOR("Radu Pirea <radu.pirea@microchip.com>");
> +MODULE_DESCRIPTION("AT91 USART MFD driver");
> +MODULE_LICENSE("GPL v2");
> -- 
> 2.17.1
> 
> 
> _______________________________________________
> linux-arm-kernel mailing list
> linux-arm-kernel@lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
Radu Pirea June 14, 2018, 8:22 a.m. UTC | #2
On 06/14/2018 10:58 AM, Ludovic Desroches wrote:
> On Wed, Jun 13, 2018 at 07:36:18PM +0300, Radu Pirea wrote:
>> This mfd driver is just a wrapper over atmel_serial driver and
>> spi-at91-usart driver. Selection of one of the drivers is based on a
>> property from device tree. If the property is not specified, the default
>> driver is atmel_serial.
>>
>> Signed-off-by: Radu Pirea <radu.pirea@microchip.com>
>> Acked-by: Rob Herring <robh@kernel.org>
>> Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
>> Acked-for-MFD-by: Lee Jones <lee.jones@linaro.org>
>> ---
>>   drivers/mfd/Kconfig      |  9 ++++++
>>   drivers/mfd/Makefile     |  1 +
>>   drivers/mfd/at91-usart.c | 69 ++++++++++++++++++++++++++++++++++++++++
>>   3 files changed, 79 insertions(+)
>>   create mode 100644 drivers/mfd/at91-usart.c
>>
>> diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
>> index b860eb5aa194..a886672b960d 100644
>> --- a/drivers/mfd/Kconfig
>> +++ b/drivers/mfd/Kconfig
>> @@ -99,6 +99,15 @@ config MFD_AAT2870_CORE
>>   	  additional drivers must be enabled in order to use the
>>   	  functionality of the device.
>>   
>> +config MFD_AT91_USART
>> +	tristate "AT91 USART Driver"
>> +	select MFD_CORE
>> +	help
>> +	  Select this to get support for AT91 USART IP. This is a wrapper
>> +	  over at91-usart-serial driver and usart-spi-driver. Only one function
>> +	  can be used at a time. The choice is done at boot time by the probe
>> +	  function of this MFD driver according to a device tree property.
>> +
>>   config MFD_ATMEL_FLEXCOM
>>   	tristate "Atmel Flexcom (Flexible Serial Communication Unit)"
>>   	select MFD_CORE
>> diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
>> index d9d2cf0d32ef..db1332aa96db 100644
>> --- a/drivers/mfd/Makefile
>> +++ b/drivers/mfd/Makefile
>> @@ -185,6 +185,7 @@ obj-$(CONFIG_MFD_SPMI_PMIC)	+= qcom-spmi-pmic.o
>>   obj-$(CONFIG_TPS65911_COMPARATOR)	+= tps65911-comparator.o
>>   obj-$(CONFIG_MFD_TPS65090)	+= tps65090.o
>>   obj-$(CONFIG_MFD_AAT2870_CORE)	+= aat2870-core.o
>> +obj-$(CONFIG_MFD_AT91_USART)	+= at91-usart.o
>>   obj-$(CONFIG_MFD_ATMEL_FLEXCOM)	+= atmel-flexcom.o
>>   obj-$(CONFIG_MFD_ATMEL_HLCDC)	+= atmel-hlcdc.o
>>   obj-$(CONFIG_MFD_ATMEL_SMC)	+= atmel-smc.o
>> diff --git a/drivers/mfd/at91-usart.c b/drivers/mfd/at91-usart.c
>> new file mode 100644
>> index 000000000000..3014ce532644
>> --- /dev/null
>> +++ b/drivers/mfd/at91-usart.c
>> @@ -0,0 +1,69 @@
>> +// SPDX-License-Identifier: GPL-2.0
>> +/*
>> + * Driver for AT91 USART
>> + *
>> + * Copyright (C) 2018 Microchip Technology
>> + *
>> + * Author: Radu Pirea <radu.pirea@microchip.com>
>> + *
>> + */
>> +
>> +#include <dt-bindings/mfd/at91-usart.h>
>> +
>> +#include <linux/module.h>
>> +#include <linux/mfd/core.h>
>> +#include <linux/property.h>
>> +
>> +static struct mfd_cell at91_usart_spi_subdev = {
>> +		.name = "at91_usart_spi",
>> +		.of_compatible = "microchip,at91sam9g45-usart-spi",
>> +	};
>> +
>> +static struct mfd_cell at91_usart_serial_subdev = {
>> +		.name = "atmel_usart_serial",
>> +		.of_compatible = "atmel,at91rm9200-usart-serial",
>> +	};
>> +
>> +static int at91_usart_mode_probe(struct platform_device *pdev)
>> +{
>> +	struct mfd_cell cell;
>> +	u32 opmode = AT91_USART_MODE_SERIAL;
>> +
>> +	device_property_read_u32(&pdev->dev, "atmel,usart-mode", &opmode);
>> +
>> +	switch (opmode) {
>> +	case AT91_USART_MODE_SPI:
>> +		cell = at91_usart_spi_subdev;
>> +		break;
>> +	case AT91_USART_MODE_SERIAL:
>> +		cell = at91_usart_serial_subdev;
>> +		break;
>> +	default:
>> +		break;
> 
> If there is an invalid opmode from the DT, you will pass a non initialized cell
> to mfd_add_device().
> 
> Regards
> 
> Ludovic

Hi Ludovic,

Tnx. That's true. How is better to do if atmel,usart-mode has an invalid 
value? To initialize cell with at91_usart_serial_subdev or to print an 
error message and return -EINVAL?

Regards.
Radu Pirea
> 
>> +	}
>> +
>> +	return devm_mfd_add_devices(&pdev->dev, PLATFORM_DEVID_AUTO, &cell, 1,
>> +			      NULL, 0, NULL);
>> +}
>> +
>> +static const struct of_device_id at91_usart_mode_of_match[] = {
>> +	{ .compatible = "atmel,at91rm9200-usart" },
>> +	{ .compatible = "atmel,at91sam9260-usart" },
>> +	{ /* sentinel */ }
>> +};
>> +
>> +MODULE_DEVICE_TABLE(of, at91_flexcom_of_match);
>> +
>> +static struct platform_driver at91_usart_mfd = {
>> +	.probe	= at91_usart_mode_probe,
>> +	.driver	= {
>> +		.name		= "at91_usart_mode",
>> +		.of_match_table	= at91_usart_mode_of_match,
>> +	},
>> +};
>> +
>> +module_platform_driver(at91_usart_mfd);
>> +
>> +MODULE_AUTHOR("Radu Pirea <radu.pirea@microchip.com>");
>> +MODULE_DESCRIPTION("AT91 USART MFD driver");
>> +MODULE_LICENSE("GPL v2");
>> -- 
>> 2.17.1
>>
>>
>> _______________________________________________
>> linux-arm-kernel mailing list
>> linux-arm-kernel@lists.infradead.org
>> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
Alexandre Belloni June 14, 2018, 8:32 a.m. UTC | #3
On 14/06/2018 11:22:25+0300, Radu Pirea wrote:
> On 06/14/2018 10:58 AM, Ludovic Desroches wrote:
> > > +static int at91_usart_mode_probe(struct platform_device *pdev)
> > > +{
> > > +	struct mfd_cell cell;
> > > +	u32 opmode = AT91_USART_MODE_SERIAL;
> > > +
> > > +	device_property_read_u32(&pdev->dev, "atmel,usart-mode", &opmode);
> > > +
> > > +	switch (opmode) {
> > > +	case AT91_USART_MODE_SPI:
> > > +		cell = at91_usart_spi_subdev;
> > > +		break;
> > > +	case AT91_USART_MODE_SERIAL:
> > > +		cell = at91_usart_serial_subdev;
> > > +		break;
> > > +	default:
> > > +		break;
> > 
> > If there is an invalid opmode from the DT, you will pass a non initialized cell
> > to mfd_add_device().
> > 
> > Regards
> > 
> > Ludovic
> 
> Hi Ludovic,
> 
> Tnx. That's true. How is better to do if atmel,usart-mode has an invalid
> value? To initialize cell with at91_usart_serial_subdev or to print an error
> message and return -EINVAL?
> 

Returning an error is probably the correct choice because it means the
DT has an invalid value (something was done and is wrong).
diff mbox

Patch

diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
index b860eb5aa194..a886672b960d 100644
--- a/drivers/mfd/Kconfig
+++ b/drivers/mfd/Kconfig
@@ -99,6 +99,15 @@  config MFD_AAT2870_CORE
 	  additional drivers must be enabled in order to use the
 	  functionality of the device.
 
+config MFD_AT91_USART
+	tristate "AT91 USART Driver"
+	select MFD_CORE
+	help
+	  Select this to get support for AT91 USART IP. This is a wrapper
+	  over at91-usart-serial driver and usart-spi-driver. Only one function
+	  can be used at a time. The choice is done at boot time by the probe
+	  function of this MFD driver according to a device tree property.
+
 config MFD_ATMEL_FLEXCOM
 	tristate "Atmel Flexcom (Flexible Serial Communication Unit)"
 	select MFD_CORE
diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
index d9d2cf0d32ef..db1332aa96db 100644
--- a/drivers/mfd/Makefile
+++ b/drivers/mfd/Makefile
@@ -185,6 +185,7 @@  obj-$(CONFIG_MFD_SPMI_PMIC)	+= qcom-spmi-pmic.o
 obj-$(CONFIG_TPS65911_COMPARATOR)	+= tps65911-comparator.o
 obj-$(CONFIG_MFD_TPS65090)	+= tps65090.o
 obj-$(CONFIG_MFD_AAT2870_CORE)	+= aat2870-core.o
+obj-$(CONFIG_MFD_AT91_USART)	+= at91-usart.o
 obj-$(CONFIG_MFD_ATMEL_FLEXCOM)	+= atmel-flexcom.o
 obj-$(CONFIG_MFD_ATMEL_HLCDC)	+= atmel-hlcdc.o
 obj-$(CONFIG_MFD_ATMEL_SMC)	+= atmel-smc.o
diff --git a/drivers/mfd/at91-usart.c b/drivers/mfd/at91-usart.c
new file mode 100644
index 000000000000..3014ce532644
--- /dev/null
+++ b/drivers/mfd/at91-usart.c
@@ -0,0 +1,69 @@ 
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Driver for AT91 USART
+ *
+ * Copyright (C) 2018 Microchip Technology
+ *
+ * Author: Radu Pirea <radu.pirea@microchip.com>
+ *
+ */
+
+#include <dt-bindings/mfd/at91-usart.h>
+
+#include <linux/module.h>
+#include <linux/mfd/core.h>
+#include <linux/property.h>
+
+static struct mfd_cell at91_usart_spi_subdev = {
+		.name = "at91_usart_spi",
+		.of_compatible = "microchip,at91sam9g45-usart-spi",
+	};
+
+static struct mfd_cell at91_usart_serial_subdev = {
+		.name = "atmel_usart_serial",
+		.of_compatible = "atmel,at91rm9200-usart-serial",
+	};
+
+static int at91_usart_mode_probe(struct platform_device *pdev)
+{
+	struct mfd_cell cell;
+	u32 opmode = AT91_USART_MODE_SERIAL;
+
+	device_property_read_u32(&pdev->dev, "atmel,usart-mode", &opmode);
+
+	switch (opmode) {
+	case AT91_USART_MODE_SPI:
+		cell = at91_usart_spi_subdev;
+		break;
+	case AT91_USART_MODE_SERIAL:
+		cell = at91_usart_serial_subdev;
+		break;
+	default:
+		break;
+	}
+
+	return devm_mfd_add_devices(&pdev->dev, PLATFORM_DEVID_AUTO, &cell, 1,
+			      NULL, 0, NULL);
+}
+
+static const struct of_device_id at91_usart_mode_of_match[] = {
+	{ .compatible = "atmel,at91rm9200-usart" },
+	{ .compatible = "atmel,at91sam9260-usart" },
+	{ /* sentinel */ }
+};
+
+MODULE_DEVICE_TABLE(of, at91_flexcom_of_match);
+
+static struct platform_driver at91_usart_mfd = {
+	.probe	= at91_usart_mode_probe,
+	.driver	= {
+		.name		= "at91_usart_mode",
+		.of_match_table	= at91_usart_mode_of_match,
+	},
+};
+
+module_platform_driver(at91_usart_mfd);
+
+MODULE_AUTHOR("Radu Pirea <radu.pirea@microchip.com>");
+MODULE_DESCRIPTION("AT91 USART MFD driver");
+MODULE_LICENSE("GPL v2");