serial: lantiq: Update driver to support new SoC

Use explicit string instead of a macro for devicetree compatible string.

This series of patches is to add support for multiple SoCs which reuse the same serial controller IP. The following patches will add another compatible string to support new Lightning Mountain(LGM) SoC. So it makes sense to have the compatible strings explicitly mentioned instead of a fixed macro.

Suggested-by Andy Shevchenko <[email protected]>

Signed-off-by Rahul Tanwar <[email protected]>

---
 drivers/tty/serial/lantiq.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

drivers/tty/serial/lantiq.c +2 -2

index 42e27b48e9cc..660d21db57dc 100644
@@ -693,7 +693,7 @@ lqasc_serial_early_console_setup(struct earlycon_device *device,
 	device->con->write = lqasc_serial_early_console_write;
 	return 0;
 }
-OF_EARLYCON_DECLARE(lantiq, DRVNAME, lqasc_serial_early_console_setup);
+OF_EARLYCON_DECLARE(lantiq, "lantiq,asc", lqasc_serial_early_console_setup);
 
 static struct uart_driver lqasc_reg = {
 	.owner =	THIS_MODULE,

@@ -792,7 +792,7 @@ lqasc_probe(struct platform_device *pdev)
 }
 
 static const struct of_device_id ltq_asc_match[] = {
-	{ .compatible = DRVNAME },
+	{ .compatible = "lantiq,asc" },
 	{},
 };
 

Signature · 1 line

2.11.0

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 <[email protected]>

Signed-off-by Rahul Tanwar <[email protected]>

---
 drivers/tty/serial/lantiq.c | 141 ++++++++++++++++++++++++++++++--------------
 1 file changed, 96 insertions(+), 45 deletions(-)

drivers/tty/serial/lantiq.c +96 -45

index 660d21db57dc..b129531dfb9a 100644
@@ -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 },
 	{},
 };
 

Signature · 1 line

2.11.0

This patch adds IRQ & ISR support in the driver for Lightning Mountain SoC.

Signed-off-by Rahul Tanwar <[email protected]>

---
 drivers/tty/serial/lantiq.c | 71 +++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 71 insertions(+)

drivers/tty/serial/lantiq.c +71 -0

index b129531dfb9a..fcbea43dc334 100644
@@ -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 },
 	{},
 };
 

Signature · 1 line

2.11.0