[PATCH] SUNIX SDC serial port driver

[PATCH] SUNIX SDC serial port driver

[Moriis Ku]

From: Morris Ku <saumah@gmail.com>

Add support for SUNIX SDC serial port

Cc: Taian Chen <taian.chen@sunix.com>
Cc: Morris Ku <morris_ku@sunix.com>
Cc: Edward Lee <Edward.lee@sunix.com>
Signed-off-by: Morris Ku <saumah@gmail.com>
---
 8250_sdc.c | 410 +++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 410 insertions(+)
 create mode 100644 8250_sdc.c

diff --git a/8250_sdc.c b/8250_sdc.c
new file mode 100644
index 0000000..3ec9ce7
--- /dev/null
+++ b/8250_sdc.c
@@ -0,0 +1,410 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * SUNIX SDC serial port driver.
+ *
+ * Copyright (C) 2021, SUNIX Co., Ltd.
+ *
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/pm_runtime.h>
+#include <linux/of_platform.h>
+#include <linux/io.h>
+#include <linux/debugfs.h>
+#include <linux/serial_8250.h>
+
+#define DRIVER_NAME		"8250_sdc"
+
+struct sdc8250_port_data {
+	u32 board_id;
+	u8 chl_number;
+	u8 version;
+	u16 tx_fifo_size;
+	u16 rx_fifo_size;
+	u32 significand;
+	u8 exponent;
+	u32 capability;
+
+	int line;
+};
+
+#define SDC_UART_UMR				0x0e
+
+#define SDC_UART_RS232				BIT(0)
+#define SDC_UART_RS422				BIT(1)
+#define SDC_UART_RS485				BIT(2)
+#define SDC_UART_MODE_MASK			GENMASK(2, 0)
+#define SDC_UART_AHDC				BIT(3)
+#define SDC_UART_CS					BIT(4)
+#define SDC_UART_AUTO_RS422485		BIT(5)
+#define SDC_UART_RS422_TERMINATION	BIT(6)
+#define SDC_UART_RS485_TERMINATION	BIT(7)
+
+struct sdc8250_data {
+	struct sdc8250_port_data data;
+	struct uart_8250_port uart;
+	struct device *dev;
+	struct resource *res;
+	int fifosize;
+	unsigned long long clk_rate;
+	u8 umr_suspend;
+};
+
+static inline struct sdc8250_data *to_sdc8250_data(
+				struct sdc8250_port_data *data)
+{
+	return container_of(data, struct sdc8250_data, data);
+}
+
+static void sdc8250_do_pm(struct uart_port *p, unsigned int state,
+				unsigned int old)
+{
+	if (!state)
+		pm_runtime_get_sync(p->dev);
+
+	serial8250_do_pm(p, state, old);
+
+	if (state)
+		pm_runtime_put_sync_suspend(p->dev);
+}
+
+static int sdc8250_rs485_config(struct uart_port *p,
+				struct serial_rs485 *rs485)
+{
+	struct sdc8250_data *data = to_sdc8250_data(p->private_data);
+	u32 flags = rs485->flags;
+	int ret;
+	u8 umr;
+
+	if (!(flags & SER_RS485_ENABLED)) {
+		if (!(data->data.capability & SDC_UART_RS232)) {
+			dev_err(data->dev, "no RS232 cap.\n");
+			ret = -EINVAL;
+			goto err_out;
+		}
+		umr = SDC_UART_RS232;
+
+	} else if ((flags & SER_RS485_ENABLED) &&
+				(flags & SER_RS485_RX_DURING_TX)) {
+		if (!(data->data.capability & SDC_UART_RS422)) {
+			dev_err(data->dev, "no RS422 cap.\n");
+			ret = -EINVAL;
+			goto err_out;
+		}
+		umr = SDC_UART_RS422;
+
+		if (flags & SER_RS485_TERMINATE_BUS) {
+			if (!(data->data.capability &
+					SDC_UART_RS422_TERMINATION)) {
+				dev_err(data->dev, "no RS422 termination cap.\n");
+				ret = -EINVAL;
+				goto err_out;
+			}
+			umr |= SDC_UART_RS422_TERMINATION;
+		}
+
+	} else if (flags & SER_RS485_ENABLED) {
+		if (!(data->data.capability & SDC_UART_RS485)) {
+			dev_err(data->dev, "no RS485 cap.\n");
+			ret = -EINVAL;
+			goto err_out;
+		}
+		umr = SDC_UART_RS485;
+
+		if (data->data.capability & SDC_UART_AHDC)
+			umr |= SDC_UART_AHDC;
+
+		if (data->data.capability & SDC_UART_CS)
+			umr |= SDC_UART_CS;
+
+		if (flags & SER_RS485_TERMINATE_BUS) {
+			if (!(data->data.capability &
+					SDC_UART_RS485_TERMINATION)) {
+				dev_err(data->dev, "no RS485 termination cap.\n");
+				ret = -EINVAL;
+				goto err_out;
+			}
+			umr |= SDC_UART_RS485_TERMINATION;
+		}
+
+	} else {
+		ret = -EINVAL;
+		goto err_out;
+	}
+
+	outb(umr, p->iobase + SDC_UART_UMR);
+	p->rs485 = *rs485;
+	return 0;
+
+err_out:
+	return ret;
+}
+
+static int sdc8250_read_property(struct sdc8250_port_data *data,
+				struct device *dev)
+{
+	int ret;
+
+	ret = device_property_read_u32(dev, "board_id", &data->board_id);
+	if (ret < 0)
+		return -EINVAL;
+	ret = device_property_read_u8(dev, "chl_number", &data->chl_number);
+	if (ret < 0)
+		return -EINVAL;
+	ret = device_property_read_u8(dev, "version", &data->version);
+	if (ret < 0)
+		return -EINVAL;
+	ret = device_property_read_u16(dev, "tx_fifo_size",
+			&data->tx_fifo_size);
+	if (ret < 0)
+		return -EINVAL;
+	ret = device_property_read_u16(dev, "rx_fifo_size",
+			&data->rx_fifo_size);
+	if (ret < 0)
+		return -EINVAL;
+	ret = device_property_read_u32(dev, "significand", &data->significand);
+	if (ret < 0)
+		return -EINVAL;
+	ret = device_property_read_u8(dev, "exponent", &data->exponent);
+	if (ret < 0)
+		return -EINVAL;
+	ret = device_property_read_u32(dev, "capability", &data->capability);
+	if (ret < 0)
+		return -EINVAL;
+
+	return 0;
+}
+
+static int sdc8250_rs485_init(struct sdc8250_data *data,
+				struct serial_rs485 *rs485)
+{
+	int ret = 0;
+	u8 umr;
+
+	if (data->data.version != 0)
+		return -EINVAL;
+
+	memset(rs485, 0, sizeof(struct serial_rs485));
+	umr = inb(data->res->start + SDC_UART_UMR);
+	if ((umr & SDC_UART_MODE_MASK) == SDC_UART_RS232) {
+		/* RS232 mode */
+
+	} else if ((umr & SDC_UART_MODE_MASK) == SDC_UART_RS422) {
+		/* RS422 mode */
+		rs485->flags = SER_RS485_ENABLED | SER_RS485_RX_DURING_TX;
+
+		if (umr & SDC_UART_RS422_TERMINATION)
+			rs485->flags |= SER_RS485_TERMINATE_BUS;
+
+	} else if ((umr & SDC_UART_MODE_MASK) == SDC_UART_RS485) {
+		/* RS485 mode */
+		rs485->flags = SER_RS485_ENABLED;
+
+		if (umr & SDC_UART_RS485_TERMINATION)
+			rs485->flags |= SER_RS485_TERMINATE_BUS;
+
+		if (data->data.capability & SDC_UART_AHDC)
+			umr |= SDC_UART_AHDC;
+
+		if (data->data.capability & SDC_UART_CS)
+			umr |= SDC_UART_CS;
+
+		outb(umr, data->res->start + SDC_UART_UMR);
+
+	} else {
+		ret = -EINVAL;
+	}
+
+	return ret;
+}
+
+#ifdef CONFIG_DEBUG_FS
+
+static struct dentry *sdc8250_debugfs;
+#define SDC8250_DEBUGFS_FORMAT		"b%d:uart%d"
+
+static void sdc8250_debugfs_add(struct sdc8250_data *data)
+{
+	struct dentry *dir;
+	char name[32];
+
+	snprintf(name, sizeof(name), SDC8250_DEBUGFS_FORMAT,
+		data->data.board_id, data->data.chl_number);
+	dir = debugfs_create_dir(name, sdc8250_debugfs);
+	debugfs_create_x8("version", 0444, dir, &data->data.version);
+	debugfs_create_x32("capability", 0444, dir, &data->data.capability);
+	debugfs_create_u32("line", 0444, dir, &data->data.line);
+}
+
+static void sdc8250_debugfs_remove(struct sdc8250_data *data)
+{
+	struct dentry *dir;
+	char name[32];
+
+	snprintf(name, sizeof(name), SDC8250_DEBUGFS_FORMAT,
+		data->data.board_id, data->data.chl_number);
+	dir = debugfs_lookup(name, sdc8250_debugfs);
+	debugfs_remove_recursive(dir);
+}
+
+static void sdc8250_debugfs_init(void)
+{
+	sdc8250_debugfs = debugfs_create_dir(DRIVER_NAME, NULL);
+}
+
+static void sdc8250_debugfs_exit(void)
+{
+	debugfs_remove(sdc8250_debugfs);
+}
+#else
+static void sdc8250_debugfs_add(struct sdc8250_data *data) {}
+static void sdc8250_debugfs_remove(struct sdc8250_data *data) {}
+static void sdc8250_debugfs_init(void) {}
+static void sdc8250_debugfs_exit(void) {}
+#endif
+
+static int sdc8250_probe(struct platform_device *pdev)
+{
+	unsigned long long exponent;
+	struct uart_8250_port *up;
+	struct sdc8250_data *data;
+	struct serial_rs485 rs485;
+	struct uart_port *p;
+	struct resource *res;
+	struct device *dev;
+	int irq;
+	int ret;
+	int i;
+
+	dev = &pdev->dev;
+
+	res = platform_get_resource(pdev, IORESOURCE_IO, 0);
+	if (!res) {
+		dev_err(dev, "no resource defined\n");
+		return -EINVAL;
+	}
+
+	irq = platform_get_irq(pdev, 0);
+	if (irq < 0)
+		return irq;
+
+	data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
+	if (!data)
+		return -ENOMEM;
+
+	ret = sdc8250_read_property(&data->data, dev);
+	if (ret < 0) {
+		dev_err(dev, "failed to read property\n");
+		return ret;
+	}
+	data->dev = dev;
+	data->res = res;
+	up = &data->uart;
+	p = &up->port;
+
+	data->fifosize = data->data.rx_fifo_size;
+	if (data->fifosize > data->data.tx_fifo_size)
+		data->fifosize = data->data.tx_fifo_size;
+
+	exponent = 1;
+	for (i = 0; i < data->data.exponent; i++)
+		exponent *= 10;
+	data->clk_rate = data->data.significand * exponent;
+
+	ret = sdc8250_rs485_init(data, &rs485);
+	if (ret < 0)
+		goto err_out;
+
+	spin_lock_init(&p->lock);
+	p->iotype       = UPIO_PORT;
+	p->iobase       = res->start;
+	p->regshift     = 0;
+	p->irq          = irq;
+	p->type         = PORT_SUNIX;
+	p->flags        = UPF_SHARE_IRQ | UPF_FIXED_PORT | UPF_FIXED_TYPE;
+	p->fifosize     = data->fifosize;
+	p->uartclk      = data->clk_rate;
+	p->private_data = &data->data;
+	p->pm           = sdc8250_do_pm;
+	p->rs485_config = sdc8250_rs485_config;
+	memcpy(&p->rs485, &rs485, sizeof(rs485));
+
+	data->data.line = serial8250_register_8250_port(up);
+	if (data->data.line < 0) {
+		ret = data->data.line;
+		goto err_out;
+	}
+	platform_set_drvdata(pdev, data);
+
+	sdc8250_debugfs_add(data);
+	return 0;
+
+err_out:
+	dev_err(dev, "failed to probe, err %d\n", ret);
+	return ret;
+}
+
+static int sdc8250_remove(struct platform_device *pdev)
+{
+	struct sdc8250_data *data = platform_get_drvdata(pdev);
+
+	sdc8250_debugfs_remove(data);
+	serial8250_unregister_port(data->data.line);
+	return 0;
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int sdc8250_suspend(struct device *dev)
+{
+	struct sdc8250_data *data = dev_get_drvdata(dev);
+
+	/* Save umr */
+	data->umr_suspend = inb(data->uart.port.iobase + SDC_UART_UMR);
+	serial8250_suspend_port(data->data.line);
+	return 0;
+}
+
+static int sdc8250_resume(struct device *dev)
+{
+	struct sdc8250_data *data = dev_get_drvdata(dev);
+
+	/* Restore umr */
+	outb(data->umr_suspend, data->uart.port.iobase + SDC_UART_UMR);
+	serial8250_resume_port(data->data.line);
+	return 0;
+}
+#endif
+
+static const struct dev_pm_ops sdc8250_pm_ops = {
+	SET_SYSTEM_SLEEP_PM_OPS(sdc8250_suspend, sdc8250_resume)
+};
+
+static struct platform_driver sdc8250_platform_driver = {
+	.driver = {
+		.name = DRIVER_NAME,
+		.pm = &sdc8250_pm_ops,
+	},
+	.probe = sdc8250_probe,
+	.remove = sdc8250_remove,
+};
+
+static int __init sdc8250_init(void)
+{
+	sdc8250_debugfs_init();
+	platform_driver_register(&sdc8250_platform_driver);
+	return 0;
+}
+module_init(sdc8250_init);
+
+static void __exit sdc8250_exit(void)
+{
+	platform_driver_unregister(&sdc8250_platform_driver);
+	sdc8250_debugfs_exit();
+}
+module_exit(sdc8250_exit);
+
+MODULE_AUTHOR("Jason Lee <jason_lee@sunix.com>");
+MODULE_DESCRIPTION("SUNIX SDC serial port driver");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:" DRIVER_NAME);
-- 
2.20.1

Re: [PATCH] SUNIX SDC serial port driver

[Greg KH]

On Fri, Jun 25, 2021 at 05:30:11PM +0800, Moriis Ku wrote:
> From: Morris Ku <saumah@gmail.com>
> 
> Add support for SUNIX SDC serial port
> 
> Cc: Taian Chen <taian.chen@sunix.com>
> Cc: Morris Ku <morris_ku@sunix.com>
> Cc: Edward Lee <Edward.lee@sunix.com>
> Signed-off-by: Morris Ku <saumah@gmail.com>
> ---
>  8250_sdc.c | 410 +++++++++++++++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 410 insertions(+)
>  create mode 100644 8250_sdc.c
> 
> diff --git a/8250_sdc.c b/8250_sdc.c
> new file mode 100644
> index 0000000..3ec9ce7
> --- /dev/null
> +++ b/8250_sdc.c

Hi,

This is the friendly patch-bot of Greg Kroah-Hartman.  You have sent him
a patch that has triggered this response.  He used to manually respond
to these common problems, but in order to save his sanity (he kept
writing the same thing over and over, yet to different people), I was
created.  Hopefully you will not take offence and will fix the problem
in your patch and resubmit it so that it can be accepted into the Linux
kernel tree.

You are receiving this message because of the following common error(s)
as indicated below:

- Your patch is malformed (tabs converted to spaces, linewrapped, etc.)
  and can not be applied.  Please read the file,
  Documentation/email-clients.txt in order to fix this.

- You sent multiple patches, yet no indication of which ones should be
  applied in which order.  Greg could just guess, but if you are
  receiving this email, he guessed wrong and the patches didn't apply.
  Please read the section entitled "The canonical patch format" in the
  kernel file, Documentation/SubmittingPatches for a description of how
  to do this so that Greg has a chance to apply these correctly.

- You did not specify a description of why the patch is needed, or
  possibly, any description at all, in the email body.  Please read the
  section entitled "The canonical patch format" in the kernel file,
  Documentation/SubmittingPatches for what is needed in order to
  properly describe the change.

- You did not write a descriptive Subject: for the patch, allowing Greg,
  and everyone else, to know what this patch is all about.  Please read
  the section entitled "The canonical patch format" in the kernel file,
  Documentation/SubmittingPatches for what a proper Subject: line should
  look like.

- This looks like a new version of a previously submitted patch, but you
  did not list below the --- line any changes from the previous version.
  Please read the section entitled "The canonical patch format" in the
  kernel file, Documentation/SubmittingPatches for what needs to be done
  here to properly describe this.

If you wish to discuss this problem further, or you have questions about
how to resolve this issue, please feel free to respond to this email and
Greg will reply once he has dug out from the pending patches received
from other developers.

thanks,

greg k-h's patch email bot

Re: [PATCH] SUNIX SDC serial port driver

[Greg KH]

On Fri, Jun 25, 2021 at 05:29:52PM +0800, Moriis Ku wrote:
> From: Morris Ku <saumah@gmail.com>
> 
> Add support for SUNIX SDC serial port
> 
> Cc: Jason Lee <jason_lee@sunix.com>
> Cc: Taian Chen <taian.chen@sunix.com>
> Cc: Morris Ku <morris_ku@sunix.com>
> Cc: Edward Lee <Edward.lee@sunix.com>
> Signed-off-by: Morris Ku <saumah@gmail.com>
> ---
>  Kconfig | 15 +++++++++++++++
>  1 file changed, 15 insertions(+)
> 
> diff --git a/Kconfig b/Kconfig
> index 603137d..e440760 100644
> --- a/Kconfig
> +++ b/Kconfig
> @@ -518,3 +518,18 @@ config SERIAL_OF_PLATFORM
>  	  are probed through devicetree, including Open Firmware based
>  	  PowerPC systems and embedded systems on architectures using the
>  	  flattened device tree format.
> +
> +config SERIAL_8250_SDC
> +	tristate "SUNIX SDC serial port support"
> +	depends on SERIAL_8250 && MFD_SUNIX_SDC
> +	help
> +	  Support for SUNIX SDC serial port.
> +
> +config SERIAL_OF_PLATFORM
> +	tristate "Devicetree based probing for 8250 ports"
> +	depends on SERIAL_8250 && OF
> +	help
> +	  This option is used for all 8250 compatible serial ports that
> +	  are probed through devicetree, including Open Firmware based
> +	  PowerPC systems and embedded systems on architectures using the
> +	  flattened device tree format.

Why did you duplicate this last entry again?

Did you test this?

thanks,

greg k-h

Re: [PATCH] SUNIX SDC serial port driver

[Greg KH]

On Fri, Jun 25, 2021 at 05:29:16PM +0800, Moriis Ku wrote:
> From: Morris Ku <saumah@gmail.com>
> 
> Add support for SUNIX SDC serial port
> 
> Cc: Jason Lee <jason_lee@sunix.com>
> Cc: Taian Chen <taian.chen@sunix.com>
> Cc: Morris Ku <morris_ku@sunix.com>
> Cc: Edward Lee <Edward.lee@sunix.com>
> Signed-off-by: Morris Ku <saumah@gmail.com>
> ---
>  Makefile | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/Makefile b/Makefile
> index a8bfb65..4dbe94c 100644
> --- a/Makefile
> +++ b/Makefile
> @@ -39,5 +39,7 @@ obj-$(CONFIG_SERIAL_8250_MID)		+= 8250_mid.o
>  obj-$(CONFIG_SERIAL_8250_PXA)		+= 8250_pxa.o
>  obj-$(CONFIG_SERIAL_8250_TEGRA)		+= 8250_tegra.o
>  obj-$(CONFIG_SERIAL_OF_PLATFORM)	+= 8250_of.o
> +obj-$(CONFIG_SERIAL_8250_SDC)		+= 8250_sdc.o
> +obj-$(CONFIG_SERIAL_OF_PLATFORM)	+= 8250_of.o

Why did you add this last line again?

And you sent multiple emails with identical subject lines, yet they did
totally different things.

Please fix up and properly send a patch series that is numbered as is
documented.

thanks,

greg k-h

[PATCH] SUNIX SDC serial port driver

[Moriis Ku]

From: Morris Ku <saumah@gmail.com>

Add support for SUNIX SDC serial port

Cc: Jason Lee <jason_lee@sunix.com>
Cc: Taian Chen <taian.chen@sunix.com>
Cc: Morris Ku <morris_ku@sunix.com>
Cc: Edward Lee <Edward.lee@sunix.com>
Signed-off-by: Morris Ku <saumah@gmail.com>
---
 Kconfig | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/Kconfig b/Kconfig
index 603137d..e440760 100644
--- a/Kconfig
+++ b/Kconfig
@@ -518,3 +518,18 @@ config SERIAL_OF_PLATFORM
 	  are probed through devicetree, including Open Firmware based
 	  PowerPC systems and embedded systems on architectures using the
 	  flattened device tree format.
+
+config SERIAL_8250_SDC
+	tristate "SUNIX SDC serial port support"
+	depends on SERIAL_8250 && MFD_SUNIX_SDC
+	help
+	  Support for SUNIX SDC serial port.
+
+config SERIAL_OF_PLATFORM
+	tristate "Devicetree based probing for 8250 ports"
+	depends on SERIAL_8250 && OF
+	help
+	  This option is used for all 8250 compatible serial ports that
+	  are probed through devicetree, including Open Firmware based
+	  PowerPC systems and embedded systems on architectures using the
+	  flattened device tree format.
-- 
2.20.1

[PATCH] SUNIX SDC serial port driver

[Moriis Ku]

From: Morris Ku <saumah@gmail.com>

Add support for SUNIX SDC serial port

Cc: Jason Lee <jason_lee@sunix.com>
Cc: Taian Chen <taian.chen@sunix.com>
Cc: Morris Ku <morris_ku@sunix.com>
Cc: Edward Lee <Edward.lee@sunix.com>
Signed-off-by: Morris Ku <saumah@gmail.com>
---
 Makefile | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/Makefile b/Makefile
index a8bfb65..4dbe94c 100644
--- a/Makefile
+++ b/Makefile
@@ -39,5 +39,7 @@ obj-$(CONFIG_SERIAL_8250_MID)		+= 8250_mid.o
 obj-$(CONFIG_SERIAL_8250_PXA)		+= 8250_pxa.o
 obj-$(CONFIG_SERIAL_8250_TEGRA)		+= 8250_tegra.o
 obj-$(CONFIG_SERIAL_OF_PLATFORM)	+= 8250_of.o
+obj-$(CONFIG_SERIAL_8250_SDC)		+= 8250_sdc.o
+obj-$(CONFIG_SERIAL_OF_PLATFORM)	+= 8250_of.o
 
 CFLAGS_8250_ingenic.o += -I$(srctree)/scripts/dtc/libfdt
-- 
2.20.1