serial: lantiq: Make IRQ & ISR assignment dynamic

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.

Suggested-by: Andy Shevchenko <andriy.shevchenko@intel.com>
Signed-off-by: Rahul Tanwar <rahul.tanwar@linux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@intel.com>
Link: https://lore.kernel.org/r/b166a0593bee191fcd77b5bdf8fedc6f6330a371.1565257887.git.rahul.tanwar@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/tty/serial/lantiq.c b/drivers/tty/serial/lantiq.c
index 660d21db57dc329f52685f2bb5c67724c75929ed..b129531dfb9a9296e4a1f4f4a6eb007f09d1b14e 100644 (file)
--- 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 },
        {},
 };