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

Franklin S Cooper Jr
2016-12-22T16:18:26Z

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.
>>