Re: [PATCH v2 3/3] serial: lantiq: Add support for Lightning Mountain SoC

From: Andy Shevchenko
Date: Thu Aug 08 2019 - 07:26:54 EST


On Thu, Aug 08, 2019 at 06:02:08PM +0800, Rahul Tanwar wrote:
> This patch adds IRQ & ISR support in the driver for Lightning Mountain SoC.
>

I dunno if DT binding should go first, otherwise, FWIW,
Reviewed-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxx>

> Signed-off-by: Rahul Tanwar <rahul.tanwar@xxxxxxxxxxxxxxx>
> ---
> drivers/tty/serial/lantiq.c | 71 +++++++++++++++++++++++++++++++++++++++++++++
> 1 file changed, 71 insertions(+)
>
> diff --git a/drivers/tty/serial/lantiq.c b/drivers/tty/serial/lantiq.c
> index b129531dfb9a..fcbea43dc334 100644
> --- a/drivers/tty/serial/lantiq.c
> +++ b/drivers/tty/serial/lantiq.c
> @@ -57,6 +57,7 @@
> #define ASC_IRNCR_TIR 0x1
> #define ASC_IRNCR_RIR 0x2
> #define ASC_IRNCR_EIR 0x4
> +#define ASC_IRNCR_MASK GENMASK(2, 0)
>
> #define ASCOPT_CSIZE 0x3
> #define TXFIFO_FL 1
> @@ -115,6 +116,7 @@ struct ltq_uart_port {
> unsigned int tx_irq;
> unsigned int rx_irq;
> unsigned int err_irq;
> + unsigned int common_irq;
> spinlock_t lock; /* exclusive access for multi core */
>
> const struct ltq_soc_data *soc;
> @@ -293,6 +295,31 @@ lqasc_rx_int(int irq, void *_port)
> return IRQ_HANDLED;
> }
>
> +static irqreturn_t lqasc_irq(int irq, void *p)
> +{
> + unsigned long flags;
> + u32 stat;
> + struct uart_port *port = p;
> + struct ltq_uart_port *ltq_port = to_ltq_uart_port(port);
> +
> + spin_lock_irqsave(&ltq_port->lock, flags);
> + stat = readl(port->membase + LTQ_ASC_IRNCR);
> + spin_unlock_irqrestore(&ltq_port->lock, flags);
> + if (!(stat & ASC_IRNCR_MASK))
> + return IRQ_NONE;
> +
> + if (stat & ASC_IRNCR_TIR)
> + lqasc_tx_int(irq, p);
> +
> + if (stat & ASC_IRNCR_RIR)
> + lqasc_rx_int(irq, p);
> +
> + if (stat & ASC_IRNCR_EIR)
> + lqasc_err_int(irq, p);
> +
> + return IRQ_HANDLED;
> +}
> +
> static unsigned int
> lqasc_tx_empty(struct uart_port *port)
> {
> @@ -677,6 +704,7 @@ lqasc_serial_early_console_setup(struct earlycon_device *device,
> return 0;
> }
> OF_EARLYCON_DECLARE(lantiq, "lantiq,asc", lqasc_serial_early_console_setup);
> +OF_EARLYCON_DECLARE(lantiq, "intel,lgm-asc", lqasc_serial_early_console_setup);
>
> static struct uart_driver lqasc_reg = {
> .owner = THIS_MODULE,
> @@ -751,6 +779,42 @@ static void free_irq_lantiq(struct uart_port *port)
> free_irq(ltq_port->err_irq, port);
> }
>
> +static int fetch_irq_intel(struct device *dev, struct ltq_uart_port *ltq_port)
> +{
> + struct uart_port *port = &ltq_port->port;
> + int ret;
> +
> + ret = of_irq_get(dev->of_node, 0);
> + if (ret < 0) {
> + dev_err(dev, "failed to fetch IRQ for serial port\n");
> + return ret;
> + }
> + ltq_port->common_irq = ret;
> + port->irq = ret;
> +
> + return 0;
> +}
> +
> +static int request_irq_intel(struct uart_port *port)
> +{
> + struct ltq_uart_port *ltq_port = to_ltq_uart_port(port);
> + int retval;
> +
> + retval = request_irq(ltq_port->common_irq, lqasc_irq, 0,
> + "asc_irq", port);
> + if (retval)
> + dev_err(port->dev, "failed to request asc_irq\n");
> +
> + return retval;
> +}
> +
> +static void free_irq_intel(struct uart_port *port)
> +{
> + struct ltq_uart_port *ltq_port = to_ltq_uart_port(port);
> +
> + free_irq(ltq_port->common_irq, port);
> +}
> +
> static int __init
> lqasc_probe(struct platform_device *pdev)
> {
> @@ -842,8 +906,15 @@ static const struct ltq_soc_data soc_data_lantiq = {
> .free_irq = free_irq_lantiq,
> };
>
> +static const struct ltq_soc_data soc_data_intel = {
> + .fetch_irq = fetch_irq_intel,
> + .request_irq = request_irq_intel,
> + .free_irq = free_irq_intel,
> +};
> +
> static const struct of_device_id ltq_asc_match[] = {
> { .compatible = "lantiq,asc", .data = &soc_data_lantiq },
> + { .compatible = "intel,lgm-asc", .data = &soc_data_intel },
> {},
> };
>
> --
> 2.11.0
>

--
With Best Regards,
Andy Shevchenko