From mboxrd@z Thu Jan 1 00:00:00 1970 From: nicolas.ferre@atmel.com (Nicolas Ferre) Date: Wed, 13 Nov 2013 17:28:55 +0100 Subject: [PATCH v4] ARM/serial: at91: switch atmel serial to use gpiolib In-Reply-To: <1383816355-2956-1-git-send-email-linus.walleij@linaro.org> References: <1383816355-2956-1-git-send-email-linus.walleij@linaro.org> Message-ID: <5283A8C7.30904@atmel.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On 07/11/2013 10:25, Linus Walleij : > This passes the errata fix using a GPIO to control the RTS pin > on one of the AT91 chips to use gpiolib instead of the > AT91-specific interfaces. Also remove the reliance on > compile-time #defines and the cpu_* check and rely on the > platform passing down the proper GPIO pin through platform > data. > > This is a prerequisite for getting rid of the local GPIO > implementation in the AT91 platform and move toward > multiplatform. > > The patch also adds device tree support for getting the > RTS GPIO pin from the device tree on DT boot paths. > > Signed-off-by: Nicolas Ferre > Acked-by: Jean-Christophe PLAGNIOL-VILLARD > Signed-off-by: Linus Walleij Hi Greg, You acknowledged a previous version of this patch which was taking a different approach with the subject: "[PATCH 1/4] ARM/serial: at91: move machine quirk into machine" In order to integrate the series build by Linus in our AT91/arm-soc flow, would you mind reviewing this v4 patch and eventually giving your blessing ;-) If it is okay on your side, I'll integrate it in a pull-request to arm-soc for 3.14. Thanks, bye, > --- > ChangeLog v3->v4: > - Assign RTS pin setup at runtime for the applicable > platforms. Drive it to 1 rather than 0 by default as > RTS is active low. Thanks to Jean-Christophe for noticing > the fine details... sorry for the fuzz :-/ > ChangeLog v2->v3: > - Instead of disallowing GPIO 0 to be used for the RTS > signal to allow null-initialized platform data to mean > "no RTS GPIO", be more generic and actually allow it, > and patch every instance of atmel_uart_data to set > .rts_gpio to -EINVAL except for the one case where we > actually use pin 21 for RTS over GPIO. > ChangeLog v1->v2: > - Skip check for UART base address from leftover hack, > if we have an RTS GPIO we just use it. > - Set default error value on GPIO pin to -EINVAL > - Fold in a device tree support patch from Nicolas Ferre > --- > .../devicetree/bindings/serial/atmel-usart.txt | 3 ++ > arch/arm/mach-at91/at91rm9200_devices.c | 10 ++++- > arch/arm/mach-at91/at91sam9260_devices.c | 7 ++++ > arch/arm/mach-at91/at91sam9261_devices.c | 4 ++ > arch/arm/mach-at91/at91sam9263_devices.c | 4 ++ > arch/arm/mach-at91/at91sam9g45_devices.c | 5 +++ > arch/arm/mach-at91/at91sam9rl_devices.c | 5 +++ > drivers/tty/serial/atmel_serial.c | 49 ++++++++++++++-------- > include/linux/platform_data/atmel.h | 1 + > 9 files changed, 68 insertions(+), 20 deletions(-) > > diff --git a/Documentation/devicetree/bindings/serial/atmel-usart.txt b/Documentation/devicetree/bindings/serial/atmel-usart.txt > index 2191dcb9f1da..3adc61c2e4ca 100644 > --- a/Documentation/devicetree/bindings/serial/atmel-usart.txt > +++ b/Documentation/devicetree/bindings/serial/atmel-usart.txt > @@ -10,6 +10,8 @@ Required properties: > Optional properties: > - atmel,use-dma-rx: use of PDC or DMA for receiving data > - atmel,use-dma-tx: use of PDC or DMA for transmitting data > +- rts-gpios: specify a GPIO for RTS line. It will use specified PIO instead of the peripheral > + function pin for the USART RTS feature. If unsure, don't specify this property. > - add dma bindings for dma transfer: > - dmas: DMA specifier, consisting of a phandle to DMA controller node, > memory peripheral interface and USART DMA channel ID, FIFO configuration. > @@ -28,6 +30,7 @@ Example: > interrupts = <7>; > atmel,use-dma-rx; > atmel,use-dma-tx; > + rts-gpios = <&pioD 15 0>; > }; > > - use DMA: > diff --git a/arch/arm/mach-at91/at91rm9200_devices.c b/arch/arm/mach-at91/at91rm9200_devices.c > index c721e9b08066..08ac5e2ff97d 100644 > --- a/arch/arm/mach-at91/at91rm9200_devices.c > +++ b/arch/arm/mach-at91/at91rm9200_devices.c > @@ -923,6 +923,7 @@ static struct resource dbgu_resources[] = { > static struct atmel_uart_data dbgu_data = { > .use_dma_tx = 0, > .use_dma_rx = 0, /* DBGU not capable of receive DMA */ > + .rts_gpio = -EINVAL, > }; > > static u64 dbgu_dmamask = DMA_BIT_MASK(32); > @@ -961,6 +962,7 @@ static struct resource uart0_resources[] = { > static struct atmel_uart_data uart0_data = { > .use_dma_tx = 1, > .use_dma_rx = 1, > + .rts_gpio = -EINVAL, > }; > > static u64 uart0_dmamask = DMA_BIT_MASK(32); > @@ -988,9 +990,10 @@ static inline void configure_usart0_pins(unsigned pins) > if (pins & ATMEL_UART_RTS) { > /* > * AT91RM9200 Errata #39 - RTS0 is not internally connected to PA21. > - * We need to drive the pin manually. Default is off (RTS is active low). > + * We need to drive the pin manually. The serial driver will driver > + * this to high when initializing. > */ > - at91_set_gpio_output(AT91_PIN_PA21, 1); > + uart0_data.rts_gpio = AT91_PIN_PA21; > } > } > > @@ -1010,6 +1013,7 @@ static struct resource uart1_resources[] = { > static struct atmel_uart_data uart1_data = { > .use_dma_tx = 1, > .use_dma_rx = 1, > + .rts_gpio = -EINVAL, > }; > > static u64 uart1_dmamask = DMA_BIT_MASK(32); > @@ -1061,6 +1065,7 @@ static struct resource uart2_resources[] = { > static struct atmel_uart_data uart2_data = { > .use_dma_tx = 1, > .use_dma_rx = 1, > + .rts_gpio = -EINVAL, > }; > > static u64 uart2_dmamask = DMA_BIT_MASK(32); > @@ -1104,6 +1109,7 @@ static struct resource uart3_resources[] = { > static struct atmel_uart_data uart3_data = { > .use_dma_tx = 1, > .use_dma_rx = 1, > + .rts_gpio = -EINVAL, > }; > > static u64 uart3_dmamask = DMA_BIT_MASK(32); > diff --git a/arch/arm/mach-at91/at91sam9260_devices.c b/arch/arm/mach-at91/at91sam9260_devices.c > index 428abfc14848..bcf4a161a3d8 100644 > --- a/arch/arm/mach-at91/at91sam9260_devices.c > +++ b/arch/arm/mach-at91/at91sam9260_devices.c > @@ -819,6 +819,7 @@ static struct resource dbgu_resources[] = { > static struct atmel_uart_data dbgu_data = { > .use_dma_tx = 0, > .use_dma_rx = 0, /* DBGU not capable of receive DMA */ > + .rts_gpio = -EINVAL, > }; > > static u64 dbgu_dmamask = DMA_BIT_MASK(32); > @@ -857,6 +858,7 @@ static struct resource uart0_resources[] = { > static struct atmel_uart_data uart0_data = { > .use_dma_tx = 1, > .use_dma_rx = 1, > + .rts_gpio = -EINVAL, > }; > > static u64 uart0_dmamask = DMA_BIT_MASK(32); > @@ -908,6 +910,7 @@ static struct resource uart1_resources[] = { > static struct atmel_uart_data uart1_data = { > .use_dma_tx = 1, > .use_dma_rx = 1, > + .rts_gpio = -EINVAL, > }; > > static u64 uart1_dmamask = DMA_BIT_MASK(32); > @@ -951,6 +954,7 @@ static struct resource uart2_resources[] = { > static struct atmel_uart_data uart2_data = { > .use_dma_tx = 1, > .use_dma_rx = 1, > + .rts_gpio = -EINVAL, > }; > > static u64 uart2_dmamask = DMA_BIT_MASK(32); > @@ -994,6 +998,7 @@ static struct resource uart3_resources[] = { > static struct atmel_uart_data uart3_data = { > .use_dma_tx = 1, > .use_dma_rx = 1, > + .rts_gpio = -EINVAL, > }; > > static u64 uart3_dmamask = DMA_BIT_MASK(32); > @@ -1037,6 +1042,7 @@ static struct resource uart4_resources[] = { > static struct atmel_uart_data uart4_data = { > .use_dma_tx = 1, > .use_dma_rx = 1, > + .rts_gpio = -EINVAL, > }; > > static u64 uart4_dmamask = DMA_BIT_MASK(32); > @@ -1075,6 +1081,7 @@ static struct resource uart5_resources[] = { > static struct atmel_uart_data uart5_data = { > .use_dma_tx = 1, > .use_dma_rx = 1, > + .rts_gpio = -EINVAL, > }; > > static u64 uart5_dmamask = DMA_BIT_MASK(32); > diff --git a/arch/arm/mach-at91/at91sam9261_devices.c b/arch/arm/mach-at91/at91sam9261_devices.c > index 4e02e9271ac9..d5b08ef9e848 100644 > --- a/arch/arm/mach-at91/at91sam9261_devices.c > +++ b/arch/arm/mach-at91/at91sam9261_devices.c > @@ -880,6 +880,7 @@ static struct resource dbgu_resources[] = { > static struct atmel_uart_data dbgu_data = { > .use_dma_tx = 0, > .use_dma_rx = 0, /* DBGU not capable of receive DMA */ > + .rts_gpio = -EINVAL, > }; > > static u64 dbgu_dmamask = DMA_BIT_MASK(32); > @@ -918,6 +919,7 @@ static struct resource uart0_resources[] = { > static struct atmel_uart_data uart0_data = { > .use_dma_tx = 1, > .use_dma_rx = 1, > + .rts_gpio = -EINVAL, > }; > > static u64 uart0_dmamask = DMA_BIT_MASK(32); > @@ -961,6 +963,7 @@ static struct resource uart1_resources[] = { > static struct atmel_uart_data uart1_data = { > .use_dma_tx = 1, > .use_dma_rx = 1, > + .rts_gpio = -EINVAL, > }; > > static u64 uart1_dmamask = DMA_BIT_MASK(32); > @@ -1004,6 +1007,7 @@ static struct resource uart2_resources[] = { > static struct atmel_uart_data uart2_data = { > .use_dma_tx = 1, > .use_dma_rx = 1, > + .rts_gpio = -EINVAL, > }; > > static u64 uart2_dmamask = DMA_BIT_MASK(32); > diff --git a/arch/arm/mach-at91/at91sam9263_devices.c b/arch/arm/mach-at91/at91sam9263_devices.c > index 3a384ef27cf6..22b13c6226cb 100644 > --- a/arch/arm/mach-at91/at91sam9263_devices.c > +++ b/arch/arm/mach-at91/at91sam9263_devices.c > @@ -1325,6 +1325,7 @@ static struct resource dbgu_resources[] = { > static struct atmel_uart_data dbgu_data = { > .use_dma_tx = 0, > .use_dma_rx = 0, /* DBGU not capable of receive DMA */ > + .rts_gpio = -EINVAL, > }; > > static u64 dbgu_dmamask = DMA_BIT_MASK(32); > @@ -1363,6 +1364,7 @@ static struct resource uart0_resources[] = { > static struct atmel_uart_data uart0_data = { > .use_dma_tx = 1, > .use_dma_rx = 1, > + .rts_gpio = -EINVAL, > }; > > static u64 uart0_dmamask = DMA_BIT_MASK(32); > @@ -1406,6 +1408,7 @@ static struct resource uart1_resources[] = { > static struct atmel_uart_data uart1_data = { > .use_dma_tx = 1, > .use_dma_rx = 1, > + .rts_gpio = -EINVAL, > }; > > static u64 uart1_dmamask = DMA_BIT_MASK(32); > @@ -1449,6 +1452,7 @@ static struct resource uart2_resources[] = { > static struct atmel_uart_data uart2_data = { > .use_dma_tx = 1, > .use_dma_rx = 1, > + .rts_gpio = -EINVAL, > }; > > static u64 uart2_dmamask = DMA_BIT_MASK(32); > diff --git a/arch/arm/mach-at91/at91sam9g45_devices.c b/arch/arm/mach-at91/at91sam9g45_devices.c > index 6b8effbffc28..89f95ed711c6 100644 > --- a/arch/arm/mach-at91/at91sam9g45_devices.c > +++ b/arch/arm/mach-at91/at91sam9g45_devices.c > @@ -1588,6 +1588,7 @@ static struct resource dbgu_resources[] = { > static struct atmel_uart_data dbgu_data = { > .use_dma_tx = 0, > .use_dma_rx = 0, > + .rts_gpio = -EINVAL, > }; > > static u64 dbgu_dmamask = DMA_BIT_MASK(32); > @@ -1626,6 +1627,7 @@ static struct resource uart0_resources[] = { > static struct atmel_uart_data uart0_data = { > .use_dma_tx = 1, > .use_dma_rx = 1, > + .rts_gpio = -EINVAL, > }; > > static u64 uart0_dmamask = DMA_BIT_MASK(32); > @@ -1669,6 +1671,7 @@ static struct resource uart1_resources[] = { > static struct atmel_uart_data uart1_data = { > .use_dma_tx = 1, > .use_dma_rx = 1, > + .rts_gpio = -EINVAL, > }; > > static u64 uart1_dmamask = DMA_BIT_MASK(32); > @@ -1712,6 +1715,7 @@ static struct resource uart2_resources[] = { > static struct atmel_uart_data uart2_data = { > .use_dma_tx = 1, > .use_dma_rx = 1, > + .rts_gpio = -EINVAL, > }; > > static u64 uart2_dmamask = DMA_BIT_MASK(32); > @@ -1755,6 +1759,7 @@ static struct resource uart3_resources[] = { > static struct atmel_uart_data uart3_data = { > .use_dma_tx = 1, > .use_dma_rx = 1, > + .rts_gpio = -EINVAL, > }; > > static u64 uart3_dmamask = DMA_BIT_MASK(32); > diff --git a/arch/arm/mach-at91/at91sam9rl_devices.c b/arch/arm/mach-at91/at91sam9rl_devices.c > index 6cf441cadf94..3c2462b15b8b 100644 > --- a/arch/arm/mach-at91/at91sam9rl_devices.c > +++ b/arch/arm/mach-at91/at91sam9rl_devices.c > @@ -957,6 +957,7 @@ static struct resource dbgu_resources[] = { > static struct atmel_uart_data dbgu_data = { > .use_dma_tx = 0, > .use_dma_rx = 0, /* DBGU not capable of receive DMA */ > + .rts_gpio = -EINVAL, > }; > > static u64 dbgu_dmamask = DMA_BIT_MASK(32); > @@ -995,6 +996,7 @@ static struct resource uart0_resources[] = { > static struct atmel_uart_data uart0_data = { > .use_dma_tx = 1, > .use_dma_rx = 1, > + .rts_gpio = -EINVAL, > }; > > static u64 uart0_dmamask = DMA_BIT_MASK(32); > @@ -1046,6 +1048,7 @@ static struct resource uart1_resources[] = { > static struct atmel_uart_data uart1_data = { > .use_dma_tx = 1, > .use_dma_rx = 1, > + .rts_gpio = -EINVAL, > }; > > static u64 uart1_dmamask = DMA_BIT_MASK(32); > @@ -1089,6 +1092,7 @@ static struct resource uart2_resources[] = { > static struct atmel_uart_data uart2_data = { > .use_dma_tx = 1, > .use_dma_rx = 1, > + .rts_gpio = -EINVAL, > }; > > static u64 uart2_dmamask = DMA_BIT_MASK(32); > @@ -1132,6 +1136,7 @@ static struct resource uart3_resources[] = { > static struct atmel_uart_data uart3_data = { > .use_dma_tx = 1, > .use_dma_rx = 1, > + .rts_gpio = -EINVAL, > }; > > static u64 uart3_dmamask = DMA_BIT_MASK(32); > diff --git a/drivers/tty/serial/atmel_serial.c b/drivers/tty/serial/atmel_serial.c > index d067285a2d20..af6765d3aedb 100644 > --- a/drivers/tty/serial/atmel_serial.c > +++ b/drivers/tty/serial/atmel_serial.c > @@ -35,21 +35,18 @@ > #include > #include > #include > +#include > #include > #include > #include > #include > #include > #include > +#include > > #include > #include > > -#ifdef CONFIG_ARM > -#include > -#include > -#endif > - > #define PDC_BUFFER_SIZE 512 > /* Revisit: We should calculate this based on the actual port settings */ > #define PDC_RX_TIMEOUT (3 * 10) /* 3 bytes */ > @@ -167,6 +164,7 @@ struct atmel_uart_port { > struct circ_buf rx_ring; > > struct serial_rs485 rs485; /* rs485 settings */ > + int rts_gpio; /* optional RTS GPIO */ > unsigned int tx_done_mask; > bool is_usart; /* usart or uart */ > struct timer_list uart_timer; /* uart timer */ > @@ -300,20 +298,16 @@ static void atmel_set_mctrl(struct uart_port *port, u_int mctrl) > unsigned int mode; > struct atmel_uart_port *atmel_port = to_atmel_uart_port(port); > > -#ifdef CONFIG_ARCH_AT91RM9200 > - if (cpu_is_at91rm9200()) { > - /* > - * AT91RM9200 Errata #39: RTS0 is not internally connected > - * to PA21. We need to drive the pin manually. > - */ > - if (port->mapbase == AT91RM9200_BASE_US0) { > - if (mctrl & TIOCM_RTS) > - at91_set_gpio_value(AT91_PIN_PA21, 0); > - else > - at91_set_gpio_value(AT91_PIN_PA21, 1); > - } > + /* > + * AT91RM9200 Errata #39: RTS0 is not internally connected > + * to PA21. We need to drive the pin as a GPIO. > + */ > + if (gpio_is_valid(atmel_port->rts_gpio)) { > + if (mctrl & TIOCM_RTS) > + gpio_set_value(atmel_port->rts_gpio, 0); > + else > + gpio_set_value(atmel_port->rts_gpio, 1); > } > -#endif > > if (mctrl & TIOCM_RTS) > control |= ATMEL_US_RTSEN; > @@ -2365,6 +2359,25 @@ static int atmel_serial_probe(struct platform_device *pdev) > port = &atmel_ports[ret]; > port->backup_imr = 0; > port->uart.line = ret; > + port->rts_gpio = -EINVAL; /* Invalid, zero could be valid */ > + if (pdata) > + port->rts_gpio = pdata->rts_gpio; > + else if (np) > + port->rts_gpio = of_get_named_gpio(np, "rts-gpios", 0); > + > + if (gpio_is_valid(port->rts_gpio)) { > + ret = devm_gpio_request(&pdev->dev, port->rts_gpio, "RTS"); > + if (ret) { > + dev_err(&pdev->dev, "error requesting RTS GPIO\n"); > + goto err; > + } > + /* Default to 1 as RTS is active low */ > + ret = gpio_direction_output(port->rts_gpio, 1); > + if (ret) { > + dev_err(&pdev->dev, "error setting up RTS GPIO\n"); > + goto err; > + } > + } > > ret = atmel_init_port(port, pdev); > if (ret) > diff --git a/include/linux/platform_data/atmel.h b/include/linux/platform_data/atmel.h > index cea9f70133c5..e26b0c14edea 100644 > --- a/include/linux/platform_data/atmel.h > +++ b/include/linux/platform_data/atmel.h > @@ -84,6 +84,7 @@ struct atmel_uart_data { > short use_dma_rx; /* use receive DMA? */ > void __iomem *regs; /* virt. base address, if any */ > struct serial_rs485 rs485; /* rs485 settings */ > + int rts_gpio; /* optional RTS GPIO */ > }; > > /* Touchscreen Controller */ > -- Nicolas Ferre