Re: [PATCH v2 2/3] serial: lantiq: Make IRQ & ISR assignment dynamic

From: Andy Shevchenko
Date: Thu Aug 08 2019 - 07:24:07 EST

On Thu, Aug 08, 2019 at 06:02:07PM +0800, Rahul Tanwar wrote:
> This driver/IP is reused across multiple SoCs. Older SoCs supported three
> separate IRQs for tx, rx & err interrupts. Newer Lightning Mountain SoC
> supports single IRQ for all of tx/rx/err interrupts. This patch modifies
> the driver design to support dynamic assignment of IRQ resources & ISRs
> based on devicetree node compatible entries.

Reviewed-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxx>

>
> Suggested-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxx>
> Signed-off-by: Rahul Tanwar <rahul.tanwar@xxxxxxxxxxxxxxx>
> ---
> drivers/tty/serial/lantiq.c | 141 ++++++++++++++++++++++++++++++--------------
> 1 file changed, 96 insertions(+), 45 deletions(-)
>
> diff --git a/drivers/tty/serial/lantiq.c b/drivers/tty/serial/lantiq.c
> index 660d21db57dc..b129531dfb9a 100644
> --- a/drivers/tty/serial/lantiq.c
> +++ b/drivers/tty/serial/lantiq.c
> @@ -100,6 +100,12 @@ static void lqasc_tx_chars(struct uart_port *port);
> static struct ltq_uart_port *lqasc_port[MAXPORTS];
> static struct uart_driver lqasc_reg;
>
> +struct ltq_soc_data {
> + int (*fetch_irq)(struct device *dev, struct ltq_uart_port *ltq_port);
> + int (*request_irq)(struct uart_port *port);
> + void (*free_irq)(struct uart_port *port);
> +};
> +
> struct ltq_uart_port {
> struct uart_port port;
> /* clock used to derive divider */
> @@ -110,6 +116,8 @@ struct ltq_uart_port {
> unsigned int rx_irq;
> unsigned int err_irq;
> spinlock_t lock; /* exclusive access for multi core */
> +
> + const struct ltq_soc_data *soc;
> };
>
> static inline void asc_update_bits(u32 clear, u32 set, void __iomem *reg)
> @@ -343,35 +351,12 @@ lqasc_startup(struct uart_port *port)
>
> spin_unlock_irqrestore(&ltq_port->lock, flags);
>
> - retval = request_irq(ltq_port->tx_irq, lqasc_tx_int,
> - 0, "asc_tx", port);
> - if (retval) {
> - pr_err("failed to request lqasc_tx_int\n");
> + retval = ltq_port->soc->request_irq(port);
> + if (retval)
> return retval;
> - }
> -
> - retval = request_irq(ltq_port->rx_irq, lqasc_rx_int,
> - 0, "asc_rx", port);
> - if (retval) {
> - pr_err("failed to request lqasc_rx_int\n");
> - goto err1;
> - }
> -
> - retval = request_irq(ltq_port->err_irq, lqasc_err_int,
> - 0, "asc_err", port);
> - if (retval) {
> - pr_err("failed to request lqasc_err_int\n");
> - goto err2;
> - }
>
> __raw_writel(ASC_IRNREN_RX | ASC_IRNREN_ERR | ASC_IRNREN_TX,
> port->membase + LTQ_ASC_IRNREN);
> - return 0;
> -
> -err2:
> - free_irq(ltq_port->rx_irq, port);
> -err1:
> - free_irq(ltq_port->tx_irq, port);
> return retval;
> }
>
> @@ -381,9 +366,7 @@ lqasc_shutdown(struct uart_port *port)
> struct ltq_uart_port *ltq_port = to_ltq_uart_port(port);
> unsigned long flags;
>
> - free_irq(ltq_port->tx_irq, port);
> - free_irq(ltq_port->rx_irq, port);
> - free_irq(ltq_port->err_irq, port);
> + ltq_port->soc->free_irq(port);
>
> spin_lock_irqsave(&ltq_port->lock, flags);
> __raw_writel(0, port->membase + LTQ_ASC_CON);
> @@ -705,24 +688,98 @@ static struct uart_driver lqasc_reg = {
> .cons = &lqasc_console,
> };
>
> +static int fetch_irq_lantiq(struct device *dev, struct ltq_uart_port *ltq_port)
> +{
> + struct uart_port *port = &ltq_port->port;
> + struct resource irqres[3];
> + int ret;
> +
> + ret = of_irq_to_resource_table(dev->of_node, irqres, 3);
> + if (ret != 3) {
> + dev_err(dev,
> + "failed to get IRQs for serial port\n");
> + return -ENODEV;
> + }
> + ltq_port->tx_irq = irqres[0].start;
> + ltq_port->rx_irq = irqres[1].start;
> + ltq_port->err_irq = irqres[2].start;
> + port->irq = irqres[0].start;
> +
> + return 0;
> +}
> +
> +static int request_irq_lantiq(struct uart_port *port)
> +{
> + struct ltq_uart_port *ltq_port = to_ltq_uart_port(port);
> + int retval;
> +
> + retval = request_irq(ltq_port->tx_irq, lqasc_tx_int,
> + 0, "asc_tx", port);
> + if (retval) {
> + dev_err(port->dev, "failed to request asc_tx\n");
> + return retval;
> + }
> +
> + retval = request_irq(ltq_port->rx_irq, lqasc_rx_int,
> + 0, "asc_rx", port);
> + if (retval) {
> + dev_err(port->dev, "failed to request asc_rx\n");
> + goto err1;
> + }
> +
> + retval = request_irq(ltq_port->err_irq, lqasc_err_int,
> + 0, "asc_err", port);
> + if (retval) {
> + dev_err(port->dev, "failed to request asc_err\n");
> + goto err2;
> + }
> + return 0;
> +
> +err2:
> + free_irq(ltq_port->rx_irq, port);
> +err1:
> + free_irq(ltq_port->tx_irq, port);
> + return retval;
> +}
> +
> +static void free_irq_lantiq(struct uart_port *port)
> +{
> + struct ltq_uart_port *ltq_port = to_ltq_uart_port(port);
> +
> + free_irq(ltq_port->tx_irq, port);
> + free_irq(ltq_port->rx_irq, port);
> + free_irq(ltq_port->err_irq, port);
> +}
> +
> static int __init
> lqasc_probe(struct platform_device *pdev)
> {
> struct device_node *node = pdev->dev.of_node;
> struct ltq_uart_port *ltq_port;
> struct uart_port *port;
> - struct resource *mmres, irqres[3];
> + struct resource *mmres;
> int line;
> int ret;
>
> mmres = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> - ret = of_irq_to_resource_table(node, irqres, 3);
> - if (!mmres || (ret != 3)) {
> + if (!mmres) {
> dev_err(&pdev->dev,
> - "failed to get memory/irq for serial port\n");
> + "failed to get memory for serial port\n");
> return -ENODEV;
> }
>
> + ltq_port = devm_kzalloc(&pdev->dev, sizeof(struct ltq_uart_port),
> + GFP_KERNEL);
> + if (!ltq_port)
> + return -ENOMEM;
> +
> + port = &ltq_port->port;
> +
> + ltq_port->soc = of_device_get_match_data(&pdev->dev);
> + ret = ltq_port->soc->fetch_irq(&pdev->dev, ltq_port);
> + if (ret)
> + return ret;
> +
> /* get serial id */
> line = of_alias_get_id(node, "serial");
> if (line < 0) {
> @@ -743,13 +800,6 @@ lqasc_probe(struct platform_device *pdev)
> return -EBUSY;
> }
>
> - ltq_port = devm_kzalloc(&pdev->dev, sizeof(struct ltq_uart_port),
> - GFP_KERNEL);
> - if (!ltq_port)
> - return -ENOMEM;
> -
> - port = &ltq_port->port;
> -
> port->iotype = SERIAL_IO_MEM;
> port->flags = UPF_BOOT_AUTOCONF | UPF_IOREMAP;
> port->ops = &lqasc_pops;
> @@ -758,7 +808,6 @@ lqasc_probe(struct platform_device *pdev)
> port->line = line;
> port->dev = &pdev->dev;
> /* unused, just to be backward-compatible */
> - port->irq = irqres[0].start;
> port->mapbase = mmres->start;
>
> if (IS_ENABLED(CONFIG_LANTIQ) && !IS_ENABLED(CONFIG_COMMON_CLK))
> @@ -778,10 +827,6 @@ lqasc_probe(struct platform_device *pdev)
> else
> ltq_port->clk = devm_clk_get(&pdev->dev, "asc");
>
> - ltq_port->tx_irq = irqres[0].start;
> - ltq_port->rx_irq = irqres[1].start;
> - ltq_port->err_irq = irqres[2].start;
> -
> spin_lock_init(&ltq_port->lock);
> lqasc_port[line] = ltq_port;
> platform_set_drvdata(pdev, ltq_port);
> @@ -791,8 +836,14 @@ lqasc_probe(struct platform_device *pdev)
> return ret;
> }
>
> +static const struct ltq_soc_data soc_data_lantiq = {
> + .fetch_irq = fetch_irq_lantiq,
> + .request_irq = request_irq_lantiq,
> + .free_irq = free_irq_lantiq,
> +};
> +
> static const struct of_device_id ltq_asc_match[] = {
> - { .compatible = "lantiq,asc" },
> + { .compatible = "lantiq,asc", .data = &soc_data_lantiq },
> {},
> };
>
> --
> 2.11.0
>

--
With Best Regards,
Andy Shevchenko