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SubjectRe: [PATCH 05/15] tty: serial: Add 8250-core based omap driver
Hi,

On Fri, Aug 15, 2014 at 07:42:33PM +0200, Sebastian Andrzej Siewior wrote:
> diff --git a/drivers/tty/serial/8250/8250_core.c b/drivers/tty/serial/8250/8250_core.c
> index cc90c19..ab003b6 100644
> --- a/drivers/tty/serial/8250/8250_core.c
> +++ b/drivers/tty/serial/8250/8250_core.c
> @@ -264,6 +264,12 @@ static const struct serial8250_config uart_config[] = {
> .fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10,
> .flags = UART_CAP_FIFO | UART_CAP_AFE,
> },
> + [PORT_OMAP_16750] = {
> + .name = "OMAP",
> + .fifo_size = 64,
> + .tx_loadsz = 64,
> + .flags = UART_CAP_FIFO | UART_CAP_EFR | UART_CAP_SLEEP,
> + },

I don't think you need this. Reasons below...

> [PORT_TEGRA] = {
> .name = "Tegra",
> .fifo_size = 32,
> @@ -1390,6 +1396,8 @@ static void serial8250_stop_rx(struct uart_port *port)
> serial8250_rpm_get(up);
>
> up->ier &= ~UART_IER_RLSI;
> + if (port->type == PORT_OMAP_16750)
> + up->ier &= ~UART_IER_RDI;

I don't see any reason why this could not be always cleared regardless
of the type:

up->ier &= ~(UART_IER_RLSI | UART_IRE_RDI);

> up->port.read_status_mask &= ~UART_LSR_DR;
> serial_port_out(port, UART_IER, up->ier);
>
> diff --git a/drivers/tty/serial/8250/8250_omap.c b/drivers/tty/serial/8250/8250_omap.c
> new file mode 100644
> index 0000000..368e9d8
> --- /dev/null
> +++ b/drivers/tty/serial/8250/8250_omap.c
> @@ -0,0 +1,911 @@
> +/*
> + * 8250-core based driver for the OMAP internal UART
> + *
> + * Copyright (C) 2014 Sebastian Andrzej Siewior
> + *
> + */
[cut]

> +static int omap8250_probe(struct platform_device *pdev)
> +{
> + struct resource *regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> + struct resource *irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
> + struct omap8250_priv *priv;
> + struct uart_8250_port up;
> + int ret;
> + void __iomem *membase;
> +
> + if (!regs || !irq) {
> + dev_err(&pdev->dev, "missing registers or irq\n");
> + return -EINVAL;
> + }
> +
> + priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
> + if (!priv) {
> + dev_err(&pdev->dev, "unable to allocate private data\n");
> + return -ENOMEM;
> + }
> + membase = devm_ioremap_nocache(&pdev->dev, regs->start,
> + resource_size(regs));
> + if (!membase)
> + return -ENODEV;
> +
> + memset(&up, 0, sizeof(up));
> + up.port.dev = &pdev->dev;
> + up.port.mapbase = regs->start;
> + up.port.membase = membase;
> + up.port.irq = irq->start;
> + /*
> + * It claims to be 16C750 compatible however it is a little different.
> + * It has EFR and has no FCR7_64byte bit. The AFE which it claims to
> + * have is enabled via EFR instead of MCR.
> + */
> + up.port.type = PORT_OMAP_16750;

Since you are not calling serial8250_do_set_termios, 8250_core.c newer
overrides the FCR set in this driver. However, if the FCR is a
problem, since Yoshihiro added the member for it to struct
uart_8250_port (commit aef9a7bd9), just make it possible for the probe
drivers to provide also it's value:

--- a/drivers/tty/serial/8250/8250_core.c
+++ b/drivers/tty/serial/8250/8250_core.c
@@ -2829,7 +2829,9 @@ static void serial8250_config_port(struct uart_port *port, int flags)
port->handle_irq = exar_handle_irq;

register_dev_spec_attr_grp(up);
- up->fcr = uart_config[up->port.type].fcr;
+
+ if (!up->fcr)
+ up->fcr = uart_config[up->port.type].fcr;
}

static int
So instead of using PORT_OMAP_16750:
up.port.type = PORT_16750;
up.capabilities = UART_CAP_FIFO | UART_CAP_EFR | UART_CAP_SLEEP;
and the fcr if needed.
up.fcr = ...

> + up.port.iotype = UPIO_MEM32;
> + up.port.flags = UPF_BOOT_AUTOCONF | UPF_FIXED_PORT | UPF_FIXED_TYPE |
> + UPF_SOFT_FLOW | UPF_HARD_FLOW;
> + up.port.private_data = priv;
> +
> + up.port.regshift = 2;
> + up.port.fifosize = 64;

You don't need to set the fifosize unless you want to replace the
value you get from uart_config array.

> + up.port.set_termios = omap_8250_set_termios;
> + up.port.pm = omap_8250_pm;
> + up.port.startup = omap_8250_startup;
> + up.port.shutdown = omap_8250_shutdown;
> + up.port.throttle = omap_8250_throttle;
> + up.port.unthrottle = omap_8250_unthrottle;
> +
> + if (pdev->dev.of_node) {
> + up.port.line = of_alias_get_id(pdev->dev.of_node, "serial");
> + of_property_read_u32(pdev->dev.of_node, "clock-frequency",
> + &up.port.uartclk);
> + priv->wakeirq = irq_of_parse_and_map(pdev->dev.of_node, 1);
> + } else {
> + up.port.line = pdev->id;
> + }
> +
> + if (up.port.line < 0) {
> + dev_err(&pdev->dev, "failed to get alias/pdev id, errno %d\n",
> + up.port.line);
> + return -ENODEV;
> + }
> + if (!up.port.uartclk) {
> + up.port.uartclk = DEFAULT_CLK_SPEED;
> + dev_warn(&pdev->dev,
> + "No clock speed specified: using default: %d\n",
> + DEFAULT_CLK_SPEED);
> + }
> +
> +#ifdef CONFIG_PM_RUNTIME
> + up.capabilities |= UART_CAP_RPM;
> +#endif

By setting this here, you will not get the capabilities from the
uart_config[type].flags if runtime PM is enabled in any case, right?

[cut]

> diff --git a/drivers/tty/serial/8250/Makefile b/drivers/tty/serial/8250/Makefile
> index 36d68d0..4bac392 100644
> --- a/drivers/tty/serial/8250/Makefile
> +++ b/drivers/tty/serial/8250/Makefile
> @@ -20,3 +20,4 @@ obj-$(CONFIG_SERIAL_8250_HUB6) += 8250_hub6.o
> obj-$(CONFIG_SERIAL_8250_FSL) += 8250_fsl.o
> obj-$(CONFIG_SERIAL_8250_DW) += 8250_dw.o
> obj-$(CONFIG_SERIAL_8250_EM) += 8250_em.o
> +obj-$(CONFIG_SERIAL_8250_OMAP) += 8250_omap.o
> diff --git a/include/uapi/linux/serial_core.h b/include/uapi/linux/serial_core.h
> index 5820269..74f9b11 100644
> --- a/include/uapi/linux/serial_core.h
> +++ b/include/uapi/linux/serial_core.h
> @@ -54,7 +54,8 @@
> #define PORT_ALTR_16550_F32 26 /* Altera 16550 UART with 32 FIFOs */
> #define PORT_ALTR_16550_F64 27 /* Altera 16550 UART with 64 FIFOs */
> #define PORT_ALTR_16550_F128 28 /* Altera 16550 UART with 128 FIFOs */
> -#define PORT_MAX_8250 28 /* max port ID */
> +#define PORT_OMAP_16750 29 /* TI's OMAP internal 16C750 compatible UART */
> +#define PORT_MAX_8250 29 /* max port ID */

So in this case I see no reason for new type.

Cheers,

--
heikki


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