[U-Boot] [PATCH 1/2] bcm2835_gpio: Implement GPIOF_FUNC
So far we could only tell the gpio framework that a GPIO was mapped as input or output, not as alternative function.
This patch adds support for determining whether a function is mapped as alternative.
Signed-off-by: Alexander Graf agraf@suse.de --- arch/arm/mach-bcm283x/include/mach/gpio.h | 2 ++ drivers/gpio/bcm2835_gpio.c | 30 +++++++++++++++++------------- 2 files changed, 19 insertions(+), 13 deletions(-)
diff --git a/arch/arm/mach-bcm283x/include/mach/gpio.h b/arch/arm/mach-bcm283x/include/mach/gpio.h index e6e5d16..b2df75a 100644 --- a/arch/arm/mach-bcm283x/include/mach/gpio.h +++ b/arch/arm/mach-bcm283x/include/mach/gpio.h @@ -66,4 +66,6 @@ struct bcm2835_gpio_platdata { unsigned long base; };
+int bcm2835_gpio_get_func_id(struct udevice *dev, unsigned gpio); + #endif /* _BCM2835_GPIO_H_ */ diff --git a/drivers/gpio/bcm2835_gpio.c b/drivers/gpio/bcm2835_gpio.c index fbc641d..8b88d79 100644 --- a/drivers/gpio/bcm2835_gpio.c +++ b/drivers/gpio/bcm2835_gpio.c @@ -44,15 +44,6 @@ static int bcm2835_gpio_direction_output(struct udevice *dev, unsigned gpio, return 0; }
-static bool bcm2835_gpio_is_output(const struct bcm2835_gpios *gpios, int gpio) -{ - u32 val; - - val = readl(&gpios->reg->gpfsel[BCM2835_GPIO_FSEL_BANK(gpio)]); - val &= BCM2835_GPIO_FSEL_MASK << BCM2835_GPIO_FSEL_SHIFT(gpio); - return val ? true : false; -} - static int bcm2835_get_value(const struct bcm2835_gpios *gpios, unsigned gpio) { unsigned val; @@ -81,15 +72,28 @@ static int bcm2835_gpio_set_value(struct udevice *dev, unsigned gpio, return 0; }
-static int bcm2835_gpio_get_function(struct udevice *dev, unsigned offset) +int bcm2835_gpio_get_func_id(struct udevice *dev, unsigned gpio) { struct bcm2835_gpios *gpios = dev_get_priv(dev); + u32 val; + + val = readl(&gpios->reg->gpfsel[BCM2835_GPIO_FSEL_BANK(gpio)]); + + return (val >> BCM2835_GPIO_FSEL_SHIFT(gpio) & BCM2835_GPIO_FSEL_MASK); +} + +static int bcm2835_gpio_get_function(struct udevice *dev, unsigned offset) +{ + int funcid = bcm2835_gpio_get_func_id(dev, offset);
- /* GPIOF_FUNC is not implemented yet */ - if (bcm2835_gpio_is_output(gpios, offset)) + switch (funcid) { + case BCM2835_GPIO_OUTPUT: return GPIOF_OUTPUT; - else + case BCM2835_GPIO_INPUT: return GPIOF_INPUT; + default: + return GPIOF_FUNC; + } }
On the raspberry pi, you can disable the serial port to gain dynamic frequency scaling which can get handy at times.
However, in such a configuration the serial controller gets its rx queue filled up with zero bytes which then happily get transmitted on to whoever calls getc() today.
This patch adds detection logic for that case by checking whether the RX pin is mapped to GPIO15 and disables the mini uart if it is not mapped properly.
That way we can leave the driver enabled in the tree and can determine during runtime whether serial is usable or not, having a single binary that allows for uart and non-uart operation.
Signed-off-by: Alexander Graf agraf@suse.de
---
v2 -> v3:
- Disable and detect pinmux in board file --- board/raspberrypi/rpi/rpi.c | 29 +++++++++++++++++++++++++++++ configs/rpi_3_32b_defconfig | 1 + configs/rpi_3_defconfig | 1 + include/configs/rpi.h | 1 + 4 files changed, 32 insertions(+)
diff --git a/board/raspberrypi/rpi/rpi.c b/board/raspberrypi/rpi/rpi.c index 4c8253d..20b0d1b 100644 --- a/board/raspberrypi/rpi/rpi.c +++ b/board/raspberrypi/rpi/rpi.c @@ -453,6 +453,35 @@ int board_init(void) return power_on_module(BCM2835_MBOX_POWER_DEVID_USB_HCD); }
+static bool rpi_is_serial_active(void) +{ +#ifndef CONFIG_PL01X_SERIAL + int serial_gpio = 15; + struct udevice *dev; + + /* + * The RPi3 disables the mini uart by default. The easiest way to find + * out whether it is available is to check if the pin is muxed. + */ + if (uclass_first_device(UCLASS_GPIO, &dev) || !dev) + return true; + + if (bcm2835_gpio_get_func_id(dev, serial_gpio) != BCM2835_GPIO_ALT5) + return false; +#endif + + return true; +} + +int board_late_init(void) +{ + /* Disable mini-UART I/O if it's not pinmuxed to our pins */ + if (!rpi_is_serial_active()) + gd->cur_serial_dev = NULL; + + return 0; +} + int board_mmc_init(bd_t *bis) { ALLOC_CACHE_ALIGN_BUFFER(struct msg_get_clock_rate, msg_clk, 1); diff --git a/configs/rpi_3_32b_defconfig b/configs/rpi_3_32b_defconfig index 922e01b..4c2f106 100644 --- a/configs/rpi_3_32b_defconfig +++ b/configs/rpi_3_32b_defconfig @@ -20,3 +20,4 @@ CONFIG_CMD_FAT=y CONFIG_CMD_FS_GENERIC=y CONFIG_PHYS_TO_BUS=y CONFIG_OF_LIBFDT=y +# CONFIG_REQUIRE_SERIAL_CONSOLE is not set diff --git a/configs/rpi_3_defconfig b/configs/rpi_3_defconfig index bff92df..288214c 100644 --- a/configs/rpi_3_defconfig +++ b/configs/rpi_3_defconfig @@ -19,3 +19,4 @@ CONFIG_CMD_FAT=y CONFIG_CMD_FS_GENERIC=y CONFIG_PHYS_TO_BUS=y CONFIG_OF_LIBFDT=y +# CONFIG_REQUIRE_SERIAL_CONSOLE is not set diff --git a/include/configs/rpi.h b/include/configs/rpi.h index b5543f4..e3b890a 100644 --- a/include/configs/rpi.h +++ b/include/configs/rpi.h @@ -22,6 +22,7 @@
/* Architecture, CPU, etc.*/ #define CONFIG_ARCH_CPU_INIT +#define CONFIG_BOARD_LATE_INIT
/* Use SoC timer for AArch32, but architected timer for AArch64 */ #ifndef CONFIG_ARM64
Hi Alex,
On 11 August 2016 at 05:38, Alexander Graf agraf@suse.de wrote:
On the raspberry pi, you can disable the serial port to gain dynamic frequency scaling which can get handy at times.
However, in such a configuration the serial controller gets its rx queue filled up with zero bytes which then happily get transmitted on to whoever calls getc() today.
This patch adds detection logic for that case by checking whether the RX pin is mapped to GPIO15 and disables the mini uart if it is not mapped properly.
That way we can leave the driver enabled in the tree and can determine during runtime whether serial is usable or not, having a single binary that allows for uart and non-uart operation.
Signed-off-by: Alexander Graf agraf@suse.de
v2 -> v3:
- Disable and detect pinmux in board file
board/raspberrypi/rpi/rpi.c | 29 +++++++++++++++++++++++++++++ configs/rpi_3_32b_defconfig | 1 + configs/rpi_3_defconfig | 1 + include/configs/rpi.h | 1 + 4 files changed, 32 insertions(+)
diff --git a/board/raspberrypi/rpi/rpi.c b/board/raspberrypi/rpi/rpi.c index 4c8253d..20b0d1b 100644 --- a/board/raspberrypi/rpi/rpi.c +++ b/board/raspberrypi/rpi/rpi.c @@ -453,6 +453,35 @@ int board_init(void) return power_on_module(BCM2835_MBOX_POWER_DEVID_USB_HCD); }
+static bool rpi_is_serial_active(void) +{ +#ifndef CONFIG_PL01X_SERIAL
int serial_gpio = 15;struct udevice *dev;/** The RPi3 disables the mini uart by default. The easiest way to find* out whether it is available is to check if the pin is muxed.*/if (uclass_first_device(UCLASS_GPIO, &dev) || !dev)return true;if (bcm2835_gpio_get_func_id(dev, serial_gpio) != BCM2835_GPIO_ALT5)return false;
Do you mean gpio_get_function()?
+#endif
return true;+}
+int board_late_init(void) +{
/* Disable mini-UART I/O if it's not pinmuxed to our pins */if (!rpi_is_serial_active())gd->cur_serial_dev = NULL;return 0;+}
int board_mmc_init(bd_t *bis) { ALLOC_CACHE_ALIGN_BUFFER(struct msg_get_clock_rate, msg_clk, 1); diff --git a/configs/rpi_3_32b_defconfig b/configs/rpi_3_32b_defconfig index 922e01b..4c2f106 100644 --- a/configs/rpi_3_32b_defconfig +++ b/configs/rpi_3_32b_defconfig @@ -20,3 +20,4 @@ CONFIG_CMD_FAT=y CONFIG_CMD_FS_GENERIC=y CONFIG_PHYS_TO_BUS=y CONFIG_OF_LIBFDT=y +# CONFIG_REQUIRE_SERIAL_CONSOLE is not set diff --git a/configs/rpi_3_defconfig b/configs/rpi_3_defconfig index bff92df..288214c 100644 --- a/configs/rpi_3_defconfig +++ b/configs/rpi_3_defconfig @@ -19,3 +19,4 @@ CONFIG_CMD_FAT=y CONFIG_CMD_FS_GENERIC=y CONFIG_PHYS_TO_BUS=y CONFIG_OF_LIBFDT=y +# CONFIG_REQUIRE_SERIAL_CONSOLE is not set diff --git a/include/configs/rpi.h b/include/configs/rpi.h index b5543f4..e3b890a 100644 --- a/include/configs/rpi.h +++ b/include/configs/rpi.h @@ -22,6 +22,7 @@
/* Architecture, CPU, etc.*/ #define CONFIG_ARCH_CPU_INIT +#define CONFIG_BOARD_LATE_INIT
/* Use SoC timer for AArch32, but architected timer for AArch64 */
#ifndef CONFIG_ARM64
1.8.5.6
Regards, Simon
Am 12.08.2016 um 00:38 schrieb Simon Glass sjg@chromium.org:
Hi Alex,
On 11 August 2016 at 05:38, Alexander Graf agraf@suse.de wrote: On the raspberry pi, you can disable the serial port to gain dynamic frequency scaling which can get handy at times.
However, in such a configuration the serial controller gets its rx queue filled up with zero bytes which then happily get transmitted on to whoever calls getc() today.
This patch adds detection logic for that case by checking whether the RX pin is mapped to GPIO15 and disables the mini uart if it is not mapped properly.
That way we can leave the driver enabled in the tree and can determine during runtime whether serial is usable or not, having a single binary that allows for uart and non-uart operation.
Signed-off-by: Alexander Graf agraf@suse.de
v2 -> v3:
- Disable and detect pinmux in board file
board/raspberrypi/rpi/rpi.c | 29 +++++++++++++++++++++++++++++ configs/rpi_3_32b_defconfig | 1 + configs/rpi_3_defconfig | 1 + include/configs/rpi.h | 1 + 4 files changed, 32 insertions(+)
diff --git a/board/raspberrypi/rpi/rpi.c b/board/raspberrypi/rpi/rpi.c index 4c8253d..20b0d1b 100644 --- a/board/raspberrypi/rpi/rpi.c +++ b/board/raspberrypi/rpi/rpi.c @@ -453,6 +453,35 @@ int board_init(void) return power_on_module(BCM2835_MBOX_POWER_DEVID_USB_HCD); }
+static bool rpi_is_serial_active(void) +{ +#ifndef CONFIG_PL01X_SERIAL
int serial_gpio = 15;struct udevice *dev;/** The RPi3 disables the mini uart by default. The easiest way to find* out whether it is available is to check if the pin is muxed.*/if (uclass_first_device(UCLASS_GPIO, &dev) || !dev)return true;if (bcm2835_gpio_get_func_id(dev, serial_gpio) != BCM2835_GPIO_ALT5)return false;Do you mean gpio_get_function()?
That only tells me whether it's in/out/other, but I need to know whether the pin is configured to exactly function 5.
Alex
On the raspberry pi, you can disable the serial port to gain dynamic frequency scaling which can get handy at times.
However, in such a configuration the serial controller gets its rx queue filled up with zero bytes which then happily get transmitted on to whoever calls getc() today.
This patch adds detection logic for that case by checking whether the RX pin is mapped to GPIO15 and disables the mini uart if it is not mapped properly.
That way we can leave the driver enabled in the tree and can determine during runtime whether serial is usable or not, having a single binary that allows for uart and non-uart operation.
Signed-off-by: Alexander Graf agraf@suse.de
---
v2 -> v3:
- Disable and detect pinmux in board file
v3 -> v4:
- Detect in early code and disable by failing serial probe --- board/raspberrypi/rpi/rpi.c | 34 +++++++++++++++++++++++++++- configs/rpi_3_32b_defconfig | 2 ++ configs/rpi_3_defconfig | 2 ++ drivers/gpio/bcm2835_gpio.c | 1 + drivers/serial/serial_bcm283x_mu.c | 3 +++ include/configs/rpi.h | 1 + include/dm/platform_data/serial_bcm283x_mu.h | 1 + 7 files changed, 43 insertions(+), 1 deletion(-)
diff --git a/board/raspberrypi/rpi/rpi.c b/board/raspberrypi/rpi/rpi.c index 4c8253d..7f057e1 100644 --- a/board/raspberrypi/rpi/rpi.c +++ b/board/raspberrypi/rpi/rpi.c @@ -51,7 +51,7 @@ U_BOOT_DEVICE(bcm2835_serials) = { .platdata = &serial_platdata, }; #else -static const struct bcm283x_mu_serial_platdata serial_platdata = { +static struct bcm283x_mu_serial_platdata serial_platdata = { .base = 0x3f215040, .clock = 250000000, .skip_init = true, @@ -453,6 +453,38 @@ int board_init(void) return power_on_module(BCM2835_MBOX_POWER_DEVID_USB_HCD); }
+#ifndef CONFIG_PL01X_SERIAL +static bool rpi_is_serial_active(void) +{ + int serial_gpio = 15; + struct udevice *dev; + + /* + * The RPi3 disables the mini uart by default. The easiest way to find + * out whether it is available is to check if the RX pin is muxed. + */ + + if (uclass_first_device(UCLASS_GPIO, &dev) || !dev) + return true; + + if (bcm2835_gpio_get_func_id(dev, serial_gpio) != BCM2835_GPIO_ALT5) + return false; + + return true; +} +#endif + +int board_early_init_f(void) +{ +#ifndef CONFIG_PL01X_SERIAL + /* Disable mini-UART I/O if it's not pinmuxed to our pins */ + if (!rpi_is_serial_active()) + serial_platdata.disabled = true; +#endif + + return 0; +} + int board_mmc_init(bd_t *bis) { ALLOC_CACHE_ALIGN_BUFFER(struct msg_get_clock_rate, msg_clk, 1); diff --git a/configs/rpi_3_32b_defconfig b/configs/rpi_3_32b_defconfig index 922e01b..c59474c 100644 --- a/configs/rpi_3_32b_defconfig +++ b/configs/rpi_3_32b_defconfig @@ -20,3 +20,5 @@ CONFIG_CMD_FAT=y CONFIG_CMD_FS_GENERIC=y CONFIG_PHYS_TO_BUS=y CONFIG_OF_LIBFDT=y +# CONFIG_REQUIRE_SERIAL_CONSOLE is not set +CONFIG_SYS_MALLOC_F_LEN=0x2000 diff --git a/configs/rpi_3_defconfig b/configs/rpi_3_defconfig index bff92df..67c4a0c 100644 --- a/configs/rpi_3_defconfig +++ b/configs/rpi_3_defconfig @@ -19,3 +19,5 @@ CONFIG_CMD_FAT=y CONFIG_CMD_FS_GENERIC=y CONFIG_PHYS_TO_BUS=y CONFIG_OF_LIBFDT=y +# CONFIG_REQUIRE_SERIAL_CONSOLE is not set +CONFIG_SYS_MALLOC_F_LEN=0x2000 diff --git a/drivers/gpio/bcm2835_gpio.c b/drivers/gpio/bcm2835_gpio.c index 8b88d79..8dd7a28 100644 --- a/drivers/gpio/bcm2835_gpio.c +++ b/drivers/gpio/bcm2835_gpio.c @@ -123,5 +123,6 @@ U_BOOT_DRIVER(gpio_bcm2835) = { .id = UCLASS_GPIO, .ops = &gpio_bcm2835_ops, .probe = bcm2835_gpio_probe, + .flags = DM_FLAG_PRE_RELOC, .priv_auto_alloc_size = sizeof(struct bcm2835_gpios), }; diff --git a/drivers/serial/serial_bcm283x_mu.c b/drivers/serial/serial_bcm283x_mu.c index 7357bbf..f4e062f 100644 --- a/drivers/serial/serial_bcm283x_mu.c +++ b/drivers/serial/serial_bcm283x_mu.c @@ -73,6 +73,9 @@ static int bcm283x_mu_serial_probe(struct udevice *dev) struct bcm283x_mu_serial_platdata *plat = dev_get_platdata(dev); struct bcm283x_mu_priv *priv = dev_get_priv(dev);
+ if (plat->disabled) + return -ENODEV; + priv->regs = (struct bcm283x_mu_regs *)plat->base;
return 0; diff --git a/include/configs/rpi.h b/include/configs/rpi.h index b5543f4..4e5b3f3 100644 --- a/include/configs/rpi.h +++ b/include/configs/rpi.h @@ -22,6 +22,7 @@
/* Architecture, CPU, etc.*/ #define CONFIG_ARCH_CPU_INIT +#define CONFIG_BOARD_EARLY_INIT_F
/* Use SoC timer for AArch32, but architected timer for AArch64 */ #ifndef CONFIG_ARM64 diff --git a/include/dm/platform_data/serial_bcm283x_mu.h b/include/dm/platform_data/serial_bcm283x_mu.h index 57ae6ad..c47d3c0 100644 --- a/include/dm/platform_data/serial_bcm283x_mu.h +++ b/include/dm/platform_data/serial_bcm283x_mu.h @@ -19,6 +19,7 @@ struct bcm283x_mu_serial_platdata { unsigned long base; unsigned int clock; bool skip_init; + bool disabled; };
#endif
On 08/15/2016 09:48 AM, Alexander Graf wrote:
On the raspberry pi, you can disable the serial port to gain dynamic frequency scaling which can get handy at times.
However, in such a configuration the serial controller gets its rx queue filled up with zero bytes which then happily get transmitted on to whoever calls getc() today.
This patch adds detection logic for that case by checking whether the RX pin is mapped to GPIO15 and disables the mini uart if it is not mapped properly.
That way we can leave the driver enabled in the tree and can determine during runtime whether serial is usable or not, having a single binary that allows for uart and non-uart operation.
Acked-by: Stephen Warren swarren@wwwdotorg.org
Nits:
I'd hope for a core DM feature to disable statically created devices rather than re-implementing it per driver, so we don't have to re-invent this each time we need it. Still, we can refactor this later if it turns out to be more generally useful.
Perhaps a separate patch for the raw serial driver feature (serial_bcm283x_mu.h, serial_bcm283x_mu.c), and the board-specific logic (all the other files)?
On 15 August 2016 at 21:30, Stephen Warren swarren@wwwdotorg.org wrote:
On 08/15/2016 09:48 AM, Alexander Graf wrote:
On the raspberry pi, you can disable the serial port to gain dynamic frequency scaling which can get handy at times.
However, in such a configuration the serial controller gets its rx queue filled up with zero bytes which then happily get transmitted on to whoever calls getc() today.
This patch adds detection logic for that case by checking whether the RX pin is mapped to GPIO15 and disables the mini uart if it is not mapped properly.
That way we can leave the driver enabled in the tree and can determine during runtime whether serial is usable or not, having a single binary that allows for uart and non-uart operation.
Acked-by: Stephen Warren swarren@wwwdotorg.org
Nits:
I'd hope for a core DM feature to disable statically created devices rather than re-implementing it per driver, so we don't have to re-invent this each time we need it. Still, we can refactor this later if it turns out to be more generally useful.
Agreed - yes let's wait until we have another case or two.
Reviewed-by: Simon Glass sjg@chromium.org
Perhaps a separate patch for the raw serial driver feature (serial_bcm283x_mu.h, serial_bcm283x_mu.c), and the board-specific logic (all the other files)?
- Simon
Am 16.08.2016 um 05:30 schrieb Stephen Warren swarren@wwwdotorg.org:
On 08/15/2016 09:48 AM, Alexander Graf wrote: On the raspberry pi, you can disable the serial port to gain dynamic frequency scaling which can get handy at times.
However, in such a configuration the serial controller gets its rx queue filled up with zero bytes which then happily get transmitted on to whoever calls getc() today.
This patch adds detection logic for that case by checking whether the RX pin is mapped to GPIO15 and disables the mini uart if it is not mapped properly.
That way we can leave the driver enabled in the tree and can determine during runtime whether serial is usable or not, having a single binary that allows for uart and non-uart operation.
Acked-by: Stephen Warren swarren@wwwdotorg.org
Nits:
I'd hope for a core DM feature to disable statically created devices rather than re-implementing it per driver, so we don't have to re-invent this each time we need it. Still, we can refactor this later if it turns out to be more generally useful.
Perhaps a separate patch for the raw serial driver feature (serial_bcm283x_mu.h, serial_bcm283x_mu.c), and the board-specific logic (all the other files)?
I was thinking about it, but figured that these two lines of code are so heavily intertwined with the fact that you want to actually set the disabled property. So I decided against splitting them out - it wouldn't benefit readability, bisectability or revertability (which are the usual reasons for splitting patches).
Alex
On Mon, Aug 15, 2016 at 05:48:51PM +0200, Alexander Graf wrote:
On the raspberry pi, you can disable the serial port to gain dynamic frequency scaling which can get handy at times.
However, in such a configuration the serial controller gets its rx queue filled up with zero bytes which then happily get transmitted on to whoever calls getc() today.
This patch adds detection logic for that case by checking whether the RX pin is mapped to GPIO15 and disables the mini uart if it is not mapped properly.
That way we can leave the driver enabled in the tree and can determine during runtime whether serial is usable or not, having a single binary that allows for uart and non-uart operation.
Signed-off-by: Alexander Graf agraf@suse.de Acked-by: Stephen Warren swarren@wwwdotorg.org Reviewed-by: Simon Glass sjg@chromium.org
Applied to u-boot/master, thanks!
On 11 August 2016 at 05:38, Alexander Graf agraf@suse.de wrote:
So far we could only tell the gpio framework that a GPIO was mapped as input or output, not as alternative function.
This patch adds support for determining whether a function is mapped as alternative.
Signed-off-by: Alexander Graf agraf@suse.de
arch/arm/mach-bcm283x/include/mach/gpio.h | 2 ++ drivers/gpio/bcm2835_gpio.c | 30 +++++++++++++++++------------- 2 files changed, 19 insertions(+), 13 deletions(-)
Reviewed-by: Simon Glass sjg@chromium.org
On 08/11/2016 05:38 AM, Alexander Graf wrote:
So far we could only tell the gpio framework that a GPIO was mapped as input or output, not as alternative function.
This patch adds support for determining whether a function is mapped as alternative.
The series, Acked-by: Stephen Warren swarren@wwwdotorg.org
In patch 2, I wonder if there shouldn't be a more "architectural" way of disabling the UART device; it seem like the method currently used could easily be broken by some change in the core code. I see you're discussing that part with Simon.
On Thu, Aug 11, 2016 at 01:38:31PM +0200, Alexander Graf wrote:
So far we could only tell the gpio framework that a GPIO was mapped as input or output, not as alternative function.
This patch adds support for determining whether a function is mapped as alternative.
Signed-off-by: Alexander Graf agraf@suse.de Reviewed-by: Simon Glass sjg@chromium.org Acked-by: Stephen Warren swarren@wwwdotorg.org
Applied to u-boot/master, thanks!
participants (4)
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Alexander Graf -
Simon Glass -
Stephen Warren -
Tom Rini