Commit 14208b38 authored by Rahul Tanwar's avatar Rahul Tanwar Committed by Greg Kroah-Hartman
Browse files

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: default avatarAndy Shevchenko <andriy.shevchenko@intel.com>
Signed-off-by: default avatarRahul Tanwar <rahul.tanwar@linux.intel.com>
Reviewed-by: default avatarAndy Shevchenko <andriy.shevchenko@intel.com>
Link: https://lore.kernel.org/r/b166a0593bee191fcd77b5bdf8fedc6f6330a371.1565257887.git.rahul.tanwar@linux.intel.com


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 0de2580f

drivers/tty/serial/lantiq.c

+96 −45
Original line number Diff line number Diff line
@@ -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 },

	{},

};

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