[PATCHv5 0/4] tty: serial: uartlite: Driver updates

[PATCHv5 0/4] tty: serial: uartlite: Driver updates

[shubhrajyoti.datta]

From: Shubhrajyoti Datta <shubhrajyoti.datta@xilinx.com>

Add clock and suspend resume support

v2:
lowercase for hex values
interrupt description updated
v3:
squashed the clock changes
v4:
make dt binding single patch
v5:
resend as the earlier series got mixed up.

Shubhrajyoti Datta (4):
  tty: serial: uartlite: Add structure for private data
  tty: serial: uartlite: Add clock adaptation
  tty: serial: uartlite: Add support for suspend and resume
  dt-bindings: serial: Add binding for uartlite

 .../bindings/serial/xlnx,opb-uartlite.txt          |  23 +++++
 drivers/tty/serial/uartlite.c                      | 112 +++++++++++++++++++--
 2 files changed, 126 insertions(+), 9 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/serial/xlnx,opb-uartlite.txt

-- 
2.7.4

[PATCHv5 1/4] tty: serial: uartlite: Add structure for private data

[shubhrajyoti.datta]

From: Shubhrajyoti Datta <shubhrajyoti.datta@xilinx.com>

Add struct uartlite_data, to store the private data of the Uartlite
driver.

Signed-off-by: Tanvi Desai <tanvi.desai@xilinx.com>
Signed-off-by: Shubhrajyoti Datta <shubhrajyoti.datta@xilinx.com>
---
 drivers/tty/serial/uartlite.c | 29 +++++++++++++++++++++--------
 1 file changed, 21 insertions(+), 8 deletions(-)

diff --git a/drivers/tty/serial/uartlite.c b/drivers/tty/serial/uartlite.c
index c47db78..0f798f7 100644
--- a/drivers/tty/serial/uartlite.c
+++ b/drivers/tty/serial/uartlite.c
@@ -54,6 +54,10 @@
 #define ULITE_CONTROL_RST_RX	0x02
 #define ULITE_CONTROL_IE	0x10
 
+struct uartlite_data {
+	const struct uartlite_reg_ops *reg_ops;
+};
+
 struct uartlite_reg_ops {
 	u32 (*in)(void __iomem *addr);
 	void (*out)(u32 val, void __iomem *addr);
@@ -91,16 +95,16 @@ static const struct uartlite_reg_ops uartlite_le = {
 
 static inline u32 uart_in32(u32 offset, struct uart_port *port)
 {
-	const struct uartlite_reg_ops *reg_ops = port->private_data;
+	struct uartlite_data *pdata = port->private_data;
 
-	return reg_ops->in(port->membase + offset);
+	return pdata->reg_ops->in(port->membase + offset);
 }
 
 static inline void uart_out32(u32 val, u32 offset, struct uart_port *port)
 {
-	const struct uartlite_reg_ops *reg_ops = port->private_data;
+	struct uartlite_data *pdata = port->private_data;
 
-	reg_ops->out(val, port->membase + offset);
+	pdata->reg_ops->out(val, port->membase + offset);
 }
 
 static struct uart_port ulite_ports[ULITE_NR_UARTS];
@@ -325,6 +329,7 @@ static void ulite_release_port(struct uart_port *port)
 
 static int ulite_request_port(struct uart_port *port)
 {
+	struct uartlite_data *pdata = port->private_data;
 	int ret;
 
 	pr_debug("ulite console: port=%p; port->mapbase=%llx\n",
@@ -342,13 +347,13 @@ static int ulite_request_port(struct uart_port *port)
 		return -EBUSY;
 	}
 
-	port->private_data = (void *)&uartlite_be;
+	pdata->reg_ops = &uartlite_be;
 	ret = uart_in32(ULITE_CONTROL, port);
 	uart_out32(ULITE_CONTROL_RST_TX, ULITE_CONTROL, port);
 	ret = uart_in32(ULITE_STATUS, port);
 	/* Endianess detection */
 	if ((ret & ULITE_STATUS_TXEMPTY) != ULITE_STATUS_TXEMPTY)
-		port->private_data = (void *)&uartlite_le;
+		pdata->reg_ops = &uartlite_le;
 
 	return 0;
 }
@@ -585,10 +590,12 @@ static struct uart_driver ulite_uart_driver = {
  * @id: requested id number.  Pass -1 for automatic port assignment
  * @base: base address of uartlite registers
  * @irq: irq number for uartlite
+ * @pdata: private data for uartlite
  *
  * Returns: 0 on success, <0 otherwise
  */
-static int ulite_assign(struct device *dev, int id, u32 base, int irq)
+static int ulite_assign(struct device *dev, int id, u32 base, int irq,
+			struct uartlite_data *pdata)
 {
 	struct uart_port *port;
 	int rc;
@@ -625,6 +632,7 @@ static int ulite_assign(struct device *dev, int id, u32 base, int irq)
 	port->dev = dev;
 	port->type = PORT_UNKNOWN;
 	port->line = id;
+	port->private_data = pdata;
 
 	dev_set_drvdata(dev, port);
 
@@ -675,6 +683,7 @@ MODULE_DEVICE_TABLE(of, ulite_of_match);
 static int ulite_probe(struct platform_device *pdev)
 {
 	struct resource *res;
+	struct uartlite_data *pdata;
 	int irq;
 	int id = pdev->id;
 #ifdef CONFIG_OF
@@ -684,6 +693,10 @@ static int ulite_probe(struct platform_device *pdev)
 	if (prop)
 		id = be32_to_cpup(prop);
 #endif
+	pdata = devm_kzalloc(&pdev->dev, sizeof(struct uartlite_data),
+			     GFP_KERNEL);
+	if (!pdata)
+		return -ENOMEM;
 
 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	if (!res)
@@ -693,7 +706,7 @@ static int ulite_probe(struct platform_device *pdev)
 	if (irq <= 0)
 		return -ENXIO;
 
-	return ulite_assign(&pdev->dev, id, res->start, irq);
+	return ulite_assign(&pdev->dev, id, res->start, irq, pdata);
 }
 
 static int ulite_remove(struct platform_device *pdev)
-- 
2.7.4

[PATCHv5 2/4] tty: serial: uartlite: Add clock adaptation

[shubhrajyoti.datta]

From: Shubhrajyoti Datta <shubhrajyoti.datta@xilinx.com>

Add support of Common Clock Framework for Uartlite driver.

Signed-off-by: Shubhrajyoti Datta <shubhrajyoti.datta@xilinx.com>
---
v2:
removed the suspend resume changes to separate driver
v3-v5:
No change

 drivers/tty/serial/uartlite.c | 49 +++++++++++++++++++++++++++++++++++++++++--
 1 file changed, 47 insertions(+), 2 deletions(-)

diff --git a/drivers/tty/serial/uartlite.c b/drivers/tty/serial/uartlite.c
index 0f798f7..b3a12be 100644
--- a/drivers/tty/serial/uartlite.c
+++ b/drivers/tty/serial/uartlite.c
@@ -21,6 +21,7 @@
 #include <linux/of_address.h>
 #include <linux/of_device.h>
 #include <linux/of_platform.h>
+#include <linux/clk.h>
 
 #define ULITE_NAME		"ttyUL"
 #define ULITE_MAJOR		204
@@ -56,6 +57,7 @@
 
 struct uartlite_data {
 	const struct uartlite_reg_ops *reg_ops;
+	struct clk *clk;
 };
 
 struct uartlite_reg_ops {
@@ -261,8 +263,15 @@ static void ulite_break_ctl(struct uart_port *port, int ctl)
 
 static int ulite_startup(struct uart_port *port)
 {
+	struct uartlite_data *pdata = port->private_data;
 	int ret;
 
+	ret = clk_enable(pdata->clk);
+	if (ret) {
+		dev_err(port->dev, "Failed to enable clock\n");
+		return ret;
+	}
+
 	ret = request_irq(port->irq, ulite_isr, IRQF_SHARED | IRQF_TRIGGER_RISING,
 			  "uartlite", port);
 	if (ret)
@@ -277,9 +286,12 @@ static int ulite_startup(struct uart_port *port)
 
 static void ulite_shutdown(struct uart_port *port)
 {
+	struct uartlite_data *pdata = port->private_data;
+
 	uart_out32(0, ULITE_CONTROL, port);
 	uart_in32(ULITE_CONTROL, port); /* dummy */
 	free_irq(port->irq, port);
+	clk_disable(pdata->clk);
 }
 
 static void ulite_set_termios(struct uart_port *port, struct ktermios *termios,
@@ -370,6 +382,17 @@ static int ulite_verify_port(struct uart_port *port, struct serial_struct *ser)
 	return -EINVAL;
 }
 
+static void ulite_pm(struct uart_port *port, unsigned int state,
+		     unsigned int oldstate)
+{
+	struct uartlite_data *pdata = port->private_data;
+
+	if (!state)
+		clk_enable(pdata->clk);
+	else
+		clk_disable(pdata->clk);
+}
+
 #ifdef CONFIG_CONSOLE_POLL
 static int ulite_get_poll_char(struct uart_port *port)
 {
@@ -405,6 +428,7 @@ static const struct uart_ops ulite_ops = {
 	.request_port	= ulite_request_port,
 	.config_port	= ulite_config_port,
 	.verify_port	= ulite_verify_port,
+	.pm		= ulite_pm,
 #ifdef CONFIG_CONSOLE_POLL
 	.poll_get_char	= ulite_get_poll_char,
 	.poll_put_char	= ulite_put_poll_char,
@@ -669,7 +693,6 @@ static int ulite_release(struct device *dev)
 /* ---------------------------------------------------------------------
  * Platform bus binding
  */
-
 #if defined(CONFIG_OF)
 /* Match table for of_platform binding */
 static const struct of_device_id ulite_of_match[] = {
@@ -684,7 +707,7 @@ static int ulite_probe(struct platform_device *pdev)
 {
 	struct resource *res;
 	struct uartlite_data *pdata;
-	int irq;
+	int irq, ret;
 	int id = pdev->id;
 #ifdef CONFIG_OF
 	const __be32 *prop;
@@ -706,11 +729,33 @@ static int ulite_probe(struct platform_device *pdev)
 	if (irq <= 0)
 		return -ENXIO;
 
+	pdata->clk = devm_clk_get(&pdev->dev, "s_axi_aclk");
+	if (IS_ERR(pdata->clk)) {
+		if (PTR_ERR(pdata->clk) != -ENOENT)
+			return PTR_ERR(pdata->clk);
+
+		/*
+		 * Clock framework support is optional, continue on
+		 * anyways if we don't find a matching clock.
+		 */
+		pdata->clk = NULL;
+	}
+
+	ret = clk_prepare(pdata->clk);
+	if (ret) {
+		dev_err(&pdev->dev, "Failed to prepare clock\n");
+		return ret;
+	}
+
 	return ulite_assign(&pdev->dev, id, res->start, irq, pdata);
 }
 
 static int ulite_remove(struct platform_device *pdev)
 {
+	struct uart_port *port = dev_get_drvdata(&pdev->dev);
+	struct uartlite_data *pdata = port->private_data;
+
+	clk_disable_unprepare(pdata->clk);
 	return ulite_release(&pdev->dev);
 }
 
-- 
2.7.4

[PATCHv5 3/4] tty: serial: uartlite: Add support for suspend and resume

[shubhrajyoti.datta]

From: Shubhrajyoti Datta <shubhrajyoti.datta@xilinx.com>

Add suspend and resume handlers for uartlite

Signed-off-by: Shubhrajyoti Datta <shubhrajyoti.datta@xilinx.com>
---
v2:
patch added
v3- v5:
No change

 drivers/tty/serial/uartlite.c | 36 ++++++++++++++++++++++++++++++++++++
 1 file changed, 36 insertions(+)

diff --git a/drivers/tty/serial/uartlite.c b/drivers/tty/serial/uartlite.c
index b3a12be..98d3ead 100644
--- a/drivers/tty/serial/uartlite.c
+++ b/drivers/tty/serial/uartlite.c
@@ -690,9 +690,44 @@ static int ulite_release(struct device *dev)
 	return rc;
 }
 
+/**
+ * ulite_suspend - Stop the device.
+ *
+ * @dev: handle to the device structure.
+ * Return: 0 always.
+ */
+static int __maybe_unused ulite_suspend(struct device *dev)
+{
+	struct uart_port *port = dev_get_drvdata(dev);
+
+	if (port)
+		uart_suspend_port(&ulite_uart_driver, port);
+
+	return 0;
+}
+
+/**
+ * ulite_resume - Resume the device.
+ *
+ * @dev: handle to the device structure.
+ * Return: 0 on success, errno otherwise.
+ */
+static int __maybe_unused ulite_resume(struct device *dev)
+{
+	struct uart_port *port = dev_get_drvdata(dev);
+
+	if (port)
+		uart_resume_port(&ulite_uart_driver, port);
+
+	return 0;
+}
+
 /* ---------------------------------------------------------------------
  * Platform bus binding
  */
+
+static SIMPLE_DEV_PM_OPS(ulite_pm_ops, ulite_suspend, ulite_resume);
+
 #if defined(CONFIG_OF)
 /* Match table for of_platform binding */
 static const struct of_device_id ulite_of_match[] = {
@@ -768,6 +803,7 @@ static struct platform_driver ulite_platform_driver = {
 	.driver = {
 		.name  = "uartlite",
 		.of_match_table = of_match_ptr(ulite_of_match),
+		.pm = &ulite_pm_ops,
 	},
 };
 
-- 
2.7.4

[PATCHv5 4/4] dt-bindings: serial: Add binding for uartlite

[shubhrajyoti.datta]

From: Shubhrajyoti Datta <shubhrajyoti.datta@xilinx.com>

The uartlite devicetree binding was missed out.
Add the binding documentation for uartlite that is already in use.

Signed-off-by: Shubhrajyoti Datta <shubhrajyoti.datta@xilinx.com>
---
v2:
lowercase for hex values
interrupt description updated
v3:
squashed the clock changes
v4:
Updated the patch description
and the interrupt description

 .../bindings/serial/xlnx,opb-uartlite.txt          | 23 ++++++++++++++++++++++
 1 file changed, 23 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/serial/xlnx,opb-uartlite.txt

diff --git a/Documentation/devicetree/bindings/serial/xlnx,opb-uartlite.txt b/Documentation/devicetree/bindings/serial/xlnx,opb-uartlite.txt
new file mode 100644
index 0000000..c37deb4
--- /dev/null
+++ b/Documentation/devicetree/bindings/serial/xlnx,opb-uartlite.txt
@@ -0,0 +1,23 @@
+Xilinx Axi Uartlite controller Device Tree Bindings
+---------------------------------------------------------
+
+Required properties:
+- compatible		: Can be either of
+				"xlnx,xps-uartlite-1.00.a"
+				"xlnx,opb-uartlite-1.00.b"
+- reg			: Physical base address and size of the Axi Uartlite
+			  registers map.
+- interrupts		: Should contain the UART controller interrupt.
+
+Optional properties:
+- port-number		: Set Uart port number
+- clock-names		: Should be "s_axi_aclk"
+- clocks		: Input clock specifier. Refer to common clock bindings.
+
+Example:
+serial@800c0000 {
+	compatible = "xlnx,xps-uartlite-1.00.a";
+	reg = <0x0 0x800c0000 0x10000>;
+	interrupts = <0x0 0x6e 0x1>;
+	port-number = <0>;
+};
-- 
2.7.4

Re: [PATCHv5 4/4] dt-bindings: serial: Add binding for uartlite

[Rob Herring]

On Sat, Jul 21, 2018 at 05:19:07PM +0530, shubhrajyoti.datta@gmail.com wrote:
> From: Shubhrajyoti Datta <shubhrajyoti.datta@xilinx.com>
> 
> The uartlite devicetree binding was missed out.
> Add the binding documentation for uartlite that is already in use.
> 
> Signed-off-by: Shubhrajyoti Datta <shubhrajyoti.datta@xilinx.com>
> ---
> v2:
> lowercase for hex values
> interrupt description updated
> v3:
> squashed the clock changes
> v4:
> Updated the patch description
> and the interrupt description
> 
>  .../bindings/serial/xlnx,opb-uartlite.txt          | 23 ++++++++++++++++++++++
>  1 file changed, 23 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/serial/xlnx,opb-uartlite.txt

Reviewed-by: Rob Herring <robh@kernel.org>