Messages in this thread | | | Subject | Re: [PATCH v7 3/6] mfd: at91-usart: added mfd driver for usart | From | Radu Pirea <> | Date | Thu, 14 Jun 2018 11:22:25 +0300 |
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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
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