Re: [PATCH 08/18] tty: serial: Add 8250-core based omap driver
* Sebastian Andrzej Siewior [140905 12:03]: > > It has been only tested as console UART on am335x-evm, dra7-evm and > beagle bone. I also did some longer raw-transfers to meassure the load. You may want to also update this with beagleboard xm now too? Regards, Tony -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH 08/18] tty: serial: Add 8250-core based omap driver
* Sebastian Andrzej Siewior bige...@linutronix.de [140905 12:03]: It has been only tested as console UART on am335x-evm, dra7-evm and beagle bone. I also did some longer raw-transfers to meassure the load. You may want to also update this with beagleboard xm now too? Regards, Tony -- To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
[PATCH 08/18] tty: serial: Add 8250-core based omap driver
This patch provides a 8250-core based UART driver for the internal OMAP UART. The long term goal is to provide the same functionality as the current OMAP uart driver and DMA support. I tried to merge omap-serial code together with the 8250-core code. There should should be hardly a noticable difference. The trigger levels are different compared to omap-serial: - omap serial TX: Interrupt comes after TX FIFO has room for 16 bytes. TX of 4096 bytes in one go results in 256 interrupts RX: Interrupt comes after there is on byte in the FIFO. RX of 4096 bytes results in 4096 interrupts. - this driver TX: Interrupt comes once the TX FIFO is empty. TX of 4096 bytes results in 65 interrupts. That means there will be gaps on the line while the driver reloads the FIFO. RX: Interrupt comes once there are 48 bytes in the FIFO or less over "longer" time frame. We have 1 / 11520 * 10^3 * 16 => 1.38… ms 1.38ms to react and purge the FIFO on 115200,8N1. Since the other driver fired after each byte it had ~5.47ms time to react. This _may_ cause problems if one relies on no missing bytes and has no flow control. On the other hand we get only 85 interrupts for the same amount of data. It has been only tested as console UART on am335x-evm, dra7-evm and beagle bone. I also did some longer raw-transfers to meassure the load. The device name is ttyS based instead of ttyO. If a ttyO based node name is required please ask udev for it. If both driver are activated (this and omap-serial) then this serial driver will take control over the device due to the link order v7…v8: - redo the register write. There is now one function for that which is used from set_termios() and runtime-resume. - drop PORT_OMAP_16750 and move the setup to the omap file. We have our own set termios function anyway (Heikki Krogerus) - use MEM instead of MEM32. TRM of AM/DM37x says that 32bit access on THR might result in data abort. We only need 32bit access in the errata function which is before we use 8250's read function so it doesn't matter. v4…v7: - change trigger levels after some tests with raw transfers. v3…v4: - drop RS485 support - wire up ->throttle / ->unthrottle v2…v3: - wire up startup & shutdown for wakeup-irq handling. - RS485 handling (well the core does). v1…v2: - added runtime PM. Could somebody could please double check this? - added omap_8250_set_termios() Signed-off-by: Sebastian Andrzej Siewior --- drivers/tty/serial/8250/8250_omap.c | 905 drivers/tty/serial/8250/Kconfig | 9 + drivers/tty/serial/8250/Makefile| 1 + 3 files changed, 915 insertions(+) create mode 100644 drivers/tty/serial/8250/8250_omap.c diff --git a/drivers/tty/serial/8250/8250_omap.c b/drivers/tty/serial/8250/8250_omap.c new file mode 100644 index ..4128bbc35089 --- /dev/null +++ b/drivers/tty/serial/8250/8250_omap.c @@ -0,0 +1,905 @@ +/* + * 8250-core based driver for the OMAP internal UART + * + * Copyright (C) 2014 Sebastian Andrzej Siewior + * + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include "8250.h" + +#define UART_DLL_EM 9 +#define UART_DLM_EM 10 + +#define DEFAULT_CLK_SPEED 4800 /* 48 Mhz*/ + +#define UART_ERRATA_i202_MDR1_ACCESS (1 << 0) +#define OMAP_UART_WER_HAS_TX_WAKEUP(1 << 1) + +#define OMAP_UART_FCR_RX_TRIG 6 +#define OMAP_UART_FCR_TX_TRIG 4 + +/* SCR register bitmasks */ +#define OMAP_UART_SCR_RX_TRIG_GRANU1_MASK (1 << 7) +#define OMAP_UART_SCR_TX_TRIG_GRANU1_MASK (1 << 6) +#define OMAP_UART_SCR_TX_EMPTY (1 << 3) +#define OMAP_UART_SCR_DMAMODE_MASK (3 << 1) +#define OMAP_UART_SCR_DMAMODE_1(1 << 1) +#define OMAP_UART_SCR_DMAMODE_CTL (1 << 0) + +/* MVR register bitmasks */ +#define OMAP_UART_MVR_SCHEME_SHIFT 30 +#define OMAP_UART_LEGACY_MVR_MAJ_MASK 0xf0 +#define OMAP_UART_LEGACY_MVR_MAJ_SHIFT 4 +#define OMAP_UART_LEGACY_MVR_MIN_MASK 0x0f +#define OMAP_UART_MVR_MAJ_MASK 0x700 +#define OMAP_UART_MVR_MAJ_SHIFT8 +#define OMAP_UART_MVR_MIN_MASK 0x3f + +#define UART_TI752_TLR_TX 0 +#define UART_TI752_TLR_RX 4 + +#define TRIGGER_TLR_MASK(x)((x & 0x3c) >> 2) +#define TRIGGER_FCR_MASK(x)(x & 3) + +/* Enable XON/XOFF flow control on output */ +#define OMAP_UART_SW_TX0x08 +/* Enable XON/XOFF flow control on input */ +#define OMAP_UART_SW_RX0x02 + +#define OMAP_UART_WER_MOD_WKUP 0x7f +#define OMAP_UART_TX_WAKEUP_EN (1 << 7) + +#define TX_TRIGGER 1 +#define RX_TRIGGER 48 + +#define OMAP_UART_TCR_RESTORE(x) ((x / 4) << 4) +#define
[PATCH 08/18] tty: serial: Add 8250-core based omap driver
This patch provides a 8250-core based UART driver for the internal OMAP UART. The long term goal is to provide the same functionality as the current OMAP uart driver and DMA support. I tried to merge omap-serial code together with the 8250-core code. There should should be hardly a noticable difference. The trigger levels are different compared to omap-serial: - omap serial TX: Interrupt comes after TX FIFO has room for 16 bytes. TX of 4096 bytes in one go results in 256 interrupts RX: Interrupt comes after there is on byte in the FIFO. RX of 4096 bytes results in 4096 interrupts. - this driver TX: Interrupt comes once the TX FIFO is empty. TX of 4096 bytes results in 65 interrupts. That means there will be gaps on the line while the driver reloads the FIFO. RX: Interrupt comes once there are 48 bytes in the FIFO or less over longer time frame. We have 1 / 11520 * 10^3 * 16 = 1.38… ms 1.38ms to react and purge the FIFO on 115200,8N1. Since the other driver fired after each byte it had ~5.47ms time to react. This _may_ cause problems if one relies on no missing bytes and has no flow control. On the other hand we get only 85 interrupts for the same amount of data. It has been only tested as console UART on am335x-evm, dra7-evm and beagle bone. I also did some longer raw-transfers to meassure the load. The device name is ttyS based instead of ttyO. If a ttyO based node name is required please ask udev for it. If both driver are activated (this and omap-serial) then this serial driver will take control over the device due to the link order v7…v8: - redo the register write. There is now one function for that which is used from set_termios() and runtime-resume. - drop PORT_OMAP_16750 and move the setup to the omap file. We have our own set termios function anyway (Heikki Krogerus) - use MEM instead of MEM32. TRM of AM/DM37x says that 32bit access on THR might result in data abort. We only need 32bit access in the errata function which is before we use 8250's read function so it doesn't matter. v4…v7: - change trigger levels after some tests with raw transfers. v3…v4: - drop RS485 support - wire up -throttle / -unthrottle v2…v3: - wire up startup shutdown for wakeup-irq handling. - RS485 handling (well the core does). v1…v2: - added runtime PM. Could somebody could please double check this? - added omap_8250_set_termios() Signed-off-by: Sebastian Andrzej Siewior bige...@linutronix.de --- drivers/tty/serial/8250/8250_omap.c | 905 drivers/tty/serial/8250/Kconfig | 9 + drivers/tty/serial/8250/Makefile| 1 + 3 files changed, 915 insertions(+) create mode 100644 drivers/tty/serial/8250/8250_omap.c diff --git a/drivers/tty/serial/8250/8250_omap.c b/drivers/tty/serial/8250/8250_omap.c new file mode 100644 index ..4128bbc35089 --- /dev/null +++ b/drivers/tty/serial/8250/8250_omap.c @@ -0,0 +1,905 @@ +/* + * 8250-core based driver for the OMAP internal UART + * + * Copyright (C) 2014 Sebastian Andrzej Siewior + * + */ + +#include linux/device.h +#include linux/io.h +#include linux/module.h +#include linux/serial_8250.h +#include linux/serial_core.h +#include linux/serial_reg.h +#include linux/platform_device.h +#include linux/slab.h +#include linux/of.h +#include linux/of_gpio.h +#include linux/of_irq.h +#include linux/delay.h +#include linux/pm_runtime.h +#include linux/console.h +#include linux/pm_qos.h + +#include 8250.h + +#define UART_DLL_EM 9 +#define UART_DLM_EM 10 + +#define DEFAULT_CLK_SPEED 4800 /* 48 Mhz*/ + +#define UART_ERRATA_i202_MDR1_ACCESS (1 0) +#define OMAP_UART_WER_HAS_TX_WAKEUP(1 1) + +#define OMAP_UART_FCR_RX_TRIG 6 +#define OMAP_UART_FCR_TX_TRIG 4 + +/* SCR register bitmasks */ +#define OMAP_UART_SCR_RX_TRIG_GRANU1_MASK (1 7) +#define OMAP_UART_SCR_TX_TRIG_GRANU1_MASK (1 6) +#define OMAP_UART_SCR_TX_EMPTY (1 3) +#define OMAP_UART_SCR_DMAMODE_MASK (3 1) +#define OMAP_UART_SCR_DMAMODE_1(1 1) +#define OMAP_UART_SCR_DMAMODE_CTL (1 0) + +/* MVR register bitmasks */ +#define OMAP_UART_MVR_SCHEME_SHIFT 30 +#define OMAP_UART_LEGACY_MVR_MAJ_MASK 0xf0 +#define OMAP_UART_LEGACY_MVR_MAJ_SHIFT 4 +#define OMAP_UART_LEGACY_MVR_MIN_MASK 0x0f +#define OMAP_UART_MVR_MAJ_MASK 0x700 +#define OMAP_UART_MVR_MAJ_SHIFT8 +#define OMAP_UART_MVR_MIN_MASK 0x3f + +#define UART_TI752_TLR_TX 0 +#define UART_TI752_TLR_RX 4 + +#define TRIGGER_TLR_MASK(x)((x 0x3c) 2) +#define TRIGGER_FCR_MASK(x)(x 3) + +/* Enable XON/XOFF flow control on output */ +#define OMAP_UART_SW_TX0x08 +/* Enable XON/XOFF flow control on input */ +#define OMAP_UART_SW_RX
