diff mbox

[2/3] serial: 8250: Add new port type for TI DA8xx/OMAPL13x/AM17xx/AM18xx

Message ID 1482265384-715-3-git-send-email-david@lechnology.com (mailing list archive)
State New, archived
Headers show

Commit Message

David Lechner Dec. 20, 2016, 8:23 p.m. UTC
This adds a new UART port type for TI DA8xx/OMAPL13x/AM17xx/AM18xx. These
SoCs have standard 8250 registers plus some extra non-standard registers.

The UART will not function unless the non-standard Power and Emulation
Management Register (PWREMU_MGMT) is configured correctly. This is
currently handled in arch/arm/mach-davinci/serial.c for non-device-tree
boards. Making this part of the UART driver will allow UART to work on
device-tree boards as well and the mach code can eventually be removed.

Signed-off-by: David Lechner <david@lechnology.com>
---
 drivers/tty/serial/8250/8250_of.c   |  1 +
 drivers/tty/serial/8250/8250_port.c | 22 ++++++++++++++++++++++
 include/uapi/linux/serial_core.h    |  3 ++-
 include/uapi/linux/serial_reg.h     |  8 ++++++++
 4 files changed, 33 insertions(+), 1 deletion(-)

Comments

Franklin Cooper Dec. 22, 2016, 3:21 p.m. UTC | #1
On 12/20/2016 02:23 PM, David Lechner wrote:
> This adds a new UART port type for TI DA8xx/OMAPL13x/AM17xx/AM18xx. These
> SoCs have standard 8250 registers plus some extra non-standard registers.
> 
> The UART will not function unless the non-standard Power and Emulation
> Management Register (PWREMU_MGMT) is configured correctly. This is
> currently handled in arch/arm/mach-davinci/serial.c for non-device-tree
> boards. Making this part of the UART driver will allow UART to work on
> device-tree boards as well and the mach code can eventually be removed.
> 
> Signed-off-by: David Lechner <david@lechnology.com>
> ---
>  drivers/tty/serial/8250/8250_of.c   |  1 +
>  drivers/tty/serial/8250/8250_port.c | 22 ++++++++++++++++++++++
>  include/uapi/linux/serial_core.h    |  3 ++-
>  include/uapi/linux/serial_reg.h     |  8 ++++++++
>  4 files changed, 33 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/tty/serial/8250/8250_of.c b/drivers/tty/serial/8250/8250_of.c
> index d25ab1c..5281252 100644
> --- a/drivers/tty/serial/8250/8250_of.c
> +++ b/drivers/tty/serial/8250/8250_of.c
> @@ -332,6 +332,7 @@ static const struct of_device_id of_platform_serial_table[] = {
>  		.data = (void *)PORT_ALTR_16550_F128, },
>  	{ .compatible = "mrvl,mmp-uart",
>  		.data = (void *)PORT_XSCALE, },
> +	{ .compatible = "ti,da830-uart", .data = (void *)PORT_DA830, },
>  	{ /* end of list */ },
>  };
>  MODULE_DEVICE_TABLE(of, of_platform_serial_table);
> diff --git a/drivers/tty/serial/8250/8250_port.c b/drivers/tty/serial/8250/8250_port.c
> index fe4399b..ea854054 100644
> --- a/drivers/tty/serial/8250/8250_port.c
> +++ b/drivers/tty/serial/8250/8250_port.c
> @@ -273,6 +273,15 @@ static const struct serial8250_config uart_config[] = {
>  		.rxtrig_bytes	= {1, 4, 8, 14},
>  		.flags		= UART_CAP_FIFO,
>  	},
> +	[PORT_DA830] = {
> +		.name		= "TI DA8xx/OMAPL13x/AM17xx/AM18xx",
> +		.fifo_size	= 16,
> +		.tx_loadsz	= 16,
> +		.fcr		= UART_FCR_DMA_SELECT | UART_FCR_ENABLE_FIFO |
> +				  UART_FCR_R_TRIG_10,
> +		.rxtrig_bytes	= {1, 4, 8, 14},
> +		.flags		= UART_CAP_FIFO | UART_CAP_AFE,
> +	},
>  };


Any reason why the fcr and flags fields are changed when compared
against PORT_16550A?
>  
>  /* Uart divisor latch read */
> @@ -2118,6 +2127,19 @@ int serial8250_do_startup(struct uart_port *port)
>  		serial_port_out(port, UART_LCR, 0);
>  	}
>  
> +	if (port->type == PORT_DA830) {
> +		/* Reset the port */
> +		serial_port_out(port, UART_IER, 0);
> +		serial_port_out(port, UART_DA830_PWREMU_MGMT, 0);
> +		mdelay(10);
> +
> +		/* Enable Tx, Rx and free run mode */
> +		serial_port_out(port, UART_DA830_PWREMU_MGMT,
> +				UART_DA830_PWREMU_MGMT_UTRST |
> +				UART_DA830_PWREMU_MGMT_URRST |
> +				UART_DA830_PWREMU_MGMT_FREE);
> +	}
> +
>  #ifdef CONFIG_SERIAL_8250_RSA
>  	/*
>  	 * If this is an RSA port, see if we can kick it up to the
> diff --git a/include/uapi/linux/serial_core.h b/include/uapi/linux/serial_core.h
> index 99dbed8..a126d05 100644
> --- a/include/uapi/linux/serial_core.h
> +++ b/include/uapi/linux/serial_core.h
> @@ -56,7 +56,8 @@
>  #define PORT_ALTR_16550_F128 28 /* Altera 16550 UART with 128 FIFOs */
>  #define PORT_RT2880	29	/* Ralink RT2880 internal UART */
>  #define PORT_16550A_FSL64 30	/* Freescale 16550 UART with 64 FIFOs */
> -#define PORT_MAX_8250	30	/* max port ID */
> +#define PORT_DA830	31	/* TI DA8xx/OMAP13x/AM17xx/AM18xx */
> +#define PORT_MAX_8250	31	/* max port ID */
>  
>  /*
>   * ARM specific type numbers.  These are not currently guaranteed
> diff --git a/include/uapi/linux/serial_reg.h b/include/uapi/linux/serial_reg.h
> index b4c0484..0e72eeb 100644
> --- a/include/uapi/linux/serial_reg.h
> +++ b/include/uapi/linux/serial_reg.h
> @@ -327,6 +327,14 @@
>  #define SERIAL_RSA_BAUD_BASE (921600)
>  #define SERIAL_RSA_BAUD_BASE_LO (SERIAL_RSA_BAUD_BASE / 8)
>  
> +/* Extra registers for TI DA8xx/OMAP13x/AM17xx/AM18xx */
> +#define UART_DA830_PWREMU_MGMT	12
> +
> +/* PWREMU_MGMT register bits */
> +#define UART_DA830_PWREMU_MGMT_FREE	(1 << 0)  /* Free-running mode */
> +#define UART_DA830_PWREMU_MGMT_URRST	(1 << 13) /* Receiver reset/enable */
> +#define UART_DA830_PWREMU_MGMT_UTRST	(1 << 14) /* Transmitter reset/enable */
> +
>  /*
>   * Extra serial register definitions for the internal UARTs
>   * in TI OMAP processors.
>
Franklin Cooper Dec. 22, 2016, 4:02 p.m. UTC | #2
On 12/22/2016 09:21 AM, Franklin S Cooper Jr wrote:
> 
> 
> On 12/20/2016 02:23 PM, David Lechner wrote:
>> This adds a new UART port type for TI DA8xx/OMAPL13x/AM17xx/AM18xx. These


Keystone SoCs also require this PWREMU_MGMT register to be configured.
So it would be nice to update this commit message to include Keystone SoCs.

>> SoCs have standard 8250 registers plus some extra non-standard registers.
>>
>> The UART will not function unless the non-standard Power and Emulation
>> Management Register (PWREMU_MGMT) is configured correctly. This is
>> currently handled in arch/arm/mach-davinci/serial.c for non-device-tree
>> boards. Making this part of the UART driver will allow UART to work on
>> device-tree boards as well and the mach code can eventually be removed.
>>
>> Signed-off-by: David Lechner <david@lechnology.com>
>> ---
>>  drivers/tty/serial/8250/8250_of.c   |  1 +
>>  drivers/tty/serial/8250/8250_port.c | 22 ++++++++++++++++++++++
>>  include/uapi/linux/serial_core.h    |  3 ++-
>>  include/uapi/linux/serial_reg.h     |  8 ++++++++
>>  4 files changed, 33 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/tty/serial/8250/8250_of.c b/drivers/tty/serial/8250/8250_of.c
>> index d25ab1c..5281252 100644
>> --- a/drivers/tty/serial/8250/8250_of.c
>> +++ b/drivers/tty/serial/8250/8250_of.c
>> @@ -332,6 +332,7 @@ static const struct of_device_id of_platform_serial_table[] = {
>>  		.data = (void *)PORT_ALTR_16550_F128, },
>>  	{ .compatible = "mrvl,mmp-uart",
>>  		.data = (void *)PORT_XSCALE, },
>> +	{ .compatible = "ti,da830-uart", .data = (void *)PORT_DA830, },
>>  	{ /* end of list */ },
>>  };
>>  MODULE_DEVICE_TABLE(of, of_platform_serial_table);
>> diff --git a/drivers/tty/serial/8250/8250_port.c b/drivers/tty/serial/8250/8250_port.c
>> index fe4399b..ea854054 100644
>> --- a/drivers/tty/serial/8250/8250_port.c
>> +++ b/drivers/tty/serial/8250/8250_port.c
>> @@ -273,6 +273,15 @@ static const struct serial8250_config uart_config[] = {
>>  		.rxtrig_bytes	= {1, 4, 8, 14},
>>  		.flags		= UART_CAP_FIFO,
>>  	},
>> +	[PORT_DA830] = {
>> +		.name		= "TI DA8xx/OMAPL13x/AM17xx/AM18xx",
>> +		.fifo_size	= 16,
>> +		.tx_loadsz	= 16,
>> +		.fcr		= UART_FCR_DMA_SELECT | UART_FCR_ENABLE_FIFO |
>> +				  UART_FCR_R_TRIG_10,
>> +		.rxtrig_bytes	= {1, 4, 8, 14},
>> +		.flags		= UART_CAP_FIFO | UART_CAP_AFE,
>> +	},
>>  };
> 
> 
> Any reason why the fcr and flags fields are changed when compared
> against PORT_16550A?
>>  
>>  /* Uart divisor latch read */
>> @@ -2118,6 +2127,19 @@ int serial8250_do_startup(struct uart_port *port)
>>  		serial_port_out(port, UART_LCR, 0);
>>  	}
>>  
>> +	if (port->type == PORT_DA830) {
>> +		/* Reset the port */
>> +		serial_port_out(port, UART_IER, 0);
>> +		serial_port_out(port, UART_DA830_PWREMU_MGMT, 0);
>> +		mdelay(10);
>> +
>> +		/* Enable Tx, Rx and free run mode */
>> +		serial_port_out(port, UART_DA830_PWREMU_MGMT,
>> +				UART_DA830_PWREMU_MGMT_UTRST |
>> +				UART_DA830_PWREMU_MGMT_URRST |
>> +				UART_DA830_PWREMU_MGMT_FREE);
>> +	}
>> +
>>  #ifdef CONFIG_SERIAL_8250_RSA
>>  	/*
>>  	 * If this is an RSA port, see if we can kick it up to the
>> diff --git a/include/uapi/linux/serial_core.h b/include/uapi/linux/serial_core.h
>> index 99dbed8..a126d05 100644
>> --- a/include/uapi/linux/serial_core.h
>> +++ b/include/uapi/linux/serial_core.h
>> @@ -56,7 +56,8 @@
>>  #define PORT_ALTR_16550_F128 28 /* Altera 16550 UART with 128 FIFOs */
>>  #define PORT_RT2880	29	/* Ralink RT2880 internal UART */
>>  #define PORT_16550A_FSL64 30	/* Freescale 16550 UART with 64 FIFOs */
>> -#define PORT_MAX_8250	30	/* max port ID */
>> +#define PORT_DA830	31	/* TI DA8xx/OMAP13x/AM17xx/AM18xx */
>> +#define PORT_MAX_8250	31	/* max port ID */
>>  
>>  /*
>>   * ARM specific type numbers.  These are not currently guaranteed
>> diff --git a/include/uapi/linux/serial_reg.h b/include/uapi/linux/serial_reg.h
>> index b4c0484..0e72eeb 100644
>> --- a/include/uapi/linux/serial_reg.h
>> +++ b/include/uapi/linux/serial_reg.h
>> @@ -327,6 +327,14 @@
>>  #define SERIAL_RSA_BAUD_BASE (921600)
>>  #define SERIAL_RSA_BAUD_BASE_LO (SERIAL_RSA_BAUD_BASE / 8)
>>  
>> +/* Extra registers for TI DA8xx/OMAP13x/AM17xx/AM18xx */
>> +#define UART_DA830_PWREMU_MGMT	12
>> +
>> +/* PWREMU_MGMT register bits */
>> +#define UART_DA830_PWREMU_MGMT_FREE	(1 << 0)  /* Free-running mode */
>> +#define UART_DA830_PWREMU_MGMT_URRST	(1 << 13) /* Receiver reset/enable */
>> +#define UART_DA830_PWREMU_MGMT_UTRST	(1 << 14) /* Transmitter reset/enable */
>> +
>>  /*
>>   * Extra serial register definitions for the internal UARTs
>>   * in TI OMAP processors.
>>
David Lechner Dec. 22, 2016, 6:16 p.m. UTC | #3
On 12/22/2016 09:21 AM, Franklin S Cooper Jr wrote:
>
>
> On 12/20/2016 02:23 PM, David Lechner wrote:
>> This adds a new UART port type for TI DA8xx/OMAPL13x/AM17xx/AM18xx. These
>> SoCs have standard 8250 registers plus some extra non-standard registers.
>>
>> The UART will not function unless the non-standard Power and Emulation
>> Management Register (PWREMU_MGMT) is configured correctly. This is
>> currently handled in arch/arm/mach-davinci/serial.c for non-device-tree
>> boards. Making this part of the UART driver will allow UART to work on
>> device-tree boards as well and the mach code can eventually be removed.
>>
>> Signed-off-by: David Lechner <david@lechnology.com>
>> ---
>>  drivers/tty/serial/8250/8250_of.c   |  1 +
>>  drivers/tty/serial/8250/8250_port.c | 22 ++++++++++++++++++++++
>>  include/uapi/linux/serial_core.h    |  3 ++-
>>  include/uapi/linux/serial_reg.h     |  8 ++++++++
>>  4 files changed, 33 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/tty/serial/8250/8250_of.c b/drivers/tty/serial/8250/8250_of.c
>> index d25ab1c..5281252 100644
>> --- a/drivers/tty/serial/8250/8250_of.c
>> +++ b/drivers/tty/serial/8250/8250_of.c
>> @@ -332,6 +332,7 @@ static const struct of_device_id of_platform_serial_table[] = {
>>  		.data = (void *)PORT_ALTR_16550_F128, },
>>  	{ .compatible = "mrvl,mmp-uart",
>>  		.data = (void *)PORT_XSCALE, },
>> +	{ .compatible = "ti,da830-uart", .data = (void *)PORT_DA830, },
>>  	{ /* end of list */ },
>>  };
>>  MODULE_DEVICE_TABLE(of, of_platform_serial_table);
>> diff --git a/drivers/tty/serial/8250/8250_port.c b/drivers/tty/serial/8250/8250_port.c
>> index fe4399b..ea854054 100644
>> --- a/drivers/tty/serial/8250/8250_port.c
>> +++ b/drivers/tty/serial/8250/8250_port.c
>> @@ -273,6 +273,15 @@ static const struct serial8250_config uart_config[] = {
>>  		.rxtrig_bytes	= {1, 4, 8, 14},
>>  		.flags		= UART_CAP_FIFO,
>>  	},
>> +	[PORT_DA830] = {
>> +		.name		= "TI DA8xx/OMAPL13x/AM17xx/AM18xx",
>> +		.fifo_size	= 16,
>> +		.tx_loadsz	= 16,
>> +		.fcr		= UART_FCR_DMA_SELECT | UART_FCR_ENABLE_FIFO |
>> +				  UART_FCR_R_TRIG_10,
>> +		.rxtrig_bytes	= {1, 4, 8, 14},
>> +		.flags		= UART_CAP_FIFO | UART_CAP_AFE,
>> +	},
>>  };
>
>
> Any reason why the fcr and flags fields are changed when compared
> against PORT_16550A?

The AM1808 TRM says to "always enable" the DMA bit. I figured setting it 
now could save someone trouble later if they wanted to add DMA support. 
It does not matter if it is set even if you are not using DMA.

Since we are using the special reset register that resets the state 
machine, setting UART_FCR_CLEAR_RCVR and UART_FCR_CLEAR_XMIT seems 
redundant.

And in my testing with an AM1808, UART_CAP_AFE is not automatically 
detected even though the chip has this capability, so it needs to be 
manually specified.
diff mbox

Patch

diff --git a/drivers/tty/serial/8250/8250_of.c b/drivers/tty/serial/8250/8250_of.c
index d25ab1c..5281252 100644
--- a/drivers/tty/serial/8250/8250_of.c
+++ b/drivers/tty/serial/8250/8250_of.c
@@ -332,6 +332,7 @@  static const struct of_device_id of_platform_serial_table[] = {
 		.data = (void *)PORT_ALTR_16550_F128, },
 	{ .compatible = "mrvl,mmp-uart",
 		.data = (void *)PORT_XSCALE, },
+	{ .compatible = "ti,da830-uart", .data = (void *)PORT_DA830, },
 	{ /* end of list */ },
 };
 MODULE_DEVICE_TABLE(of, of_platform_serial_table);
diff --git a/drivers/tty/serial/8250/8250_port.c b/drivers/tty/serial/8250/8250_port.c
index fe4399b..ea854054 100644
--- a/drivers/tty/serial/8250/8250_port.c
+++ b/drivers/tty/serial/8250/8250_port.c
@@ -273,6 +273,15 @@  static const struct serial8250_config uart_config[] = {
 		.rxtrig_bytes	= {1, 4, 8, 14},
 		.flags		= UART_CAP_FIFO,
 	},
+	[PORT_DA830] = {
+		.name		= "TI DA8xx/OMAPL13x/AM17xx/AM18xx",
+		.fifo_size	= 16,
+		.tx_loadsz	= 16,
+		.fcr		= UART_FCR_DMA_SELECT | UART_FCR_ENABLE_FIFO |
+				  UART_FCR_R_TRIG_10,
+		.rxtrig_bytes	= {1, 4, 8, 14},
+		.flags		= UART_CAP_FIFO | UART_CAP_AFE,
+	},
 };
 
 /* Uart divisor latch read */
@@ -2118,6 +2127,19 @@  int serial8250_do_startup(struct uart_port *port)
 		serial_port_out(port, UART_LCR, 0);
 	}
 
+	if (port->type == PORT_DA830) {
+		/* Reset the port */
+		serial_port_out(port, UART_IER, 0);
+		serial_port_out(port, UART_DA830_PWREMU_MGMT, 0);
+		mdelay(10);
+
+		/* Enable Tx, Rx and free run mode */
+		serial_port_out(port, UART_DA830_PWREMU_MGMT,
+				UART_DA830_PWREMU_MGMT_UTRST |
+				UART_DA830_PWREMU_MGMT_URRST |
+				UART_DA830_PWREMU_MGMT_FREE);
+	}
+
 #ifdef CONFIG_SERIAL_8250_RSA
 	/*
 	 * If this is an RSA port, see if we can kick it up to the
diff --git a/include/uapi/linux/serial_core.h b/include/uapi/linux/serial_core.h
index 99dbed8..a126d05 100644
--- a/include/uapi/linux/serial_core.h
+++ b/include/uapi/linux/serial_core.h
@@ -56,7 +56,8 @@ 
 #define PORT_ALTR_16550_F128 28 /* Altera 16550 UART with 128 FIFOs */
 #define PORT_RT2880	29	/* Ralink RT2880 internal UART */
 #define PORT_16550A_FSL64 30	/* Freescale 16550 UART with 64 FIFOs */
-#define PORT_MAX_8250	30	/* max port ID */
+#define PORT_DA830	31	/* TI DA8xx/OMAP13x/AM17xx/AM18xx */
+#define PORT_MAX_8250	31	/* max port ID */
 
 /*
  * ARM specific type numbers.  These are not currently guaranteed
diff --git a/include/uapi/linux/serial_reg.h b/include/uapi/linux/serial_reg.h
index b4c0484..0e72eeb 100644
--- a/include/uapi/linux/serial_reg.h
+++ b/include/uapi/linux/serial_reg.h
@@ -327,6 +327,14 @@ 
 #define SERIAL_RSA_BAUD_BASE (921600)
 #define SERIAL_RSA_BAUD_BASE_LO (SERIAL_RSA_BAUD_BASE / 8)
 
+/* Extra registers for TI DA8xx/OMAP13x/AM17xx/AM18xx */
+#define UART_DA830_PWREMU_MGMT	12
+
+/* PWREMU_MGMT register bits */
+#define UART_DA830_PWREMU_MGMT_FREE	(1 << 0)  /* Free-running mode */
+#define UART_DA830_PWREMU_MGMT_URRST	(1 << 13) /* Receiver reset/enable */
+#define UART_DA830_PWREMU_MGMT_UTRST	(1 << 14) /* Transmitter reset/enable */
+
 /*
  * Extra serial register definitions for the internal UARTs
  * in TI OMAP processors.