[PATCH v5 00/11] serial/gpio: exar: Fixes and support for IOT2000

[PATCH v5 00/11] serial/gpio: exar: Fixes and support for IOT2000

[Jan Kiszka]

This makes the gpio-exar driver usable, which was prevented by a number
of fatal bugs, and adds support for the SIMATIC IOT2040 to the 8250-exar
driver and, indirectly, to gpio-exar as well. It's a cross-subsystem
series, so I'm also cross-posting to the serial and gpio lists.

Changes in v5:
 - factor out exar8250_platform hook setup as separate patch
 - pass properties to __xr17v35x_register_gpio
 - constant property support for platform_device_add_properties

Jan

Jan Kiszka (11):
  serial: exar: Leave MPIOs as output for Commtech adapters
  gpio-exar/8250-exar: Do not even instantiate a GPIO device for
    Commtech cards
  gpio-exar/8250-exar: Fix passing in of parent PCI device
  gpio: exar: Allocate resources on behalf of the platform device
  gpio: exar: Fix iomap request
  gpio: exar: Fix reading of directions and values
  gpio-exar/8250-exar: Rearrange gpiochip parenthood
  serial: exar: Factor out platform hooks
  platform: Accept const properties
  gpio-exar/8250-exar: Make set of exported GPIOs configurable
  serial: exar: Add support for IOT2040 device

 drivers/base/platform.c             |   2 +-
 drivers/gpio/gpio-exar.c            |  75 +++++++-------
 drivers/tty/serial/8250/8250_exar.c | 188 ++++++++++++++++++++++++++++++++++--
 include/linux/platform_device.h     |   2 +-
 4 files changed, 218 insertions(+), 49 deletions(-)

-- 
2.12.3

[PATCH v5 01/11] serial: exar: Leave MPIOs as output for Commtech adapters

[Jan Kiszka]

Commtech adapters apparently need the original setting as outputs, see
https://marc.info/?l=linux-gpio&m=149557425201323&w=2. Account for that.

Fixes: 7dea8165f1d6 ("serial: exar: Preconfigure xr17v35x MPIOs as output")
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
---
 drivers/tty/serial/8250/8250_exar.c | 15 +++++++++++----
 1 file changed, 11 insertions(+), 4 deletions(-)

diff --git a/drivers/tty/serial/8250/8250_exar.c b/drivers/tty/serial/8250/8250_exar.c
index b4fa585156c7..8984e8b2d524 100644
--- a/drivers/tty/serial/8250/8250_exar.c
+++ b/drivers/tty/serial/8250/8250_exar.c
@@ -171,19 +171,26 @@ pci_xr17c154_setup(struct exar8250 *priv, struct pci_dev *pcidev,
 	return default_setup(priv, pcidev, idx, offset, port);
 }
 
-static void setup_gpio(u8 __iomem *p)
+static void setup_gpio(struct pci_dev *pcidev, u8 __iomem *p)
 {
+	/*
+	 * The Commtech adapters required the MPIOs to be driven low. The Exar
+	 * devices will export them as GPIOs, so we pre-configure them safely
+	 * as inputs.
+	 */
+	u8 dir = pcidev->vendor == PCI_VENDOR_ID_EXAR ? 0xff : 0x00;
+
 	writeb(0x00, p + UART_EXAR_MPIOINT_7_0);
 	writeb(0x00, p + UART_EXAR_MPIOLVL_7_0);
 	writeb(0x00, p + UART_EXAR_MPIO3T_7_0);
 	writeb(0x00, p + UART_EXAR_MPIOINV_7_0);
-	writeb(0xff, p + UART_EXAR_MPIOSEL_7_0);
+	writeb(dir,  p + UART_EXAR_MPIOSEL_7_0);
 	writeb(0x00, p + UART_EXAR_MPIOOD_7_0);
 	writeb(0x00, p + UART_EXAR_MPIOINT_15_8);
 	writeb(0x00, p + UART_EXAR_MPIOLVL_15_8);
 	writeb(0x00, p + UART_EXAR_MPIO3T_15_8);
 	writeb(0x00, p + UART_EXAR_MPIOINV_15_8);
-	writeb(0xff, p + UART_EXAR_MPIOSEL_15_8);
+	writeb(dir,  p + UART_EXAR_MPIOSEL_15_8);
 	writeb(0x00, p + UART_EXAR_MPIOOD_15_8);
 }
 
@@ -236,7 +243,7 @@ pci_xr17v35x_setup(struct exar8250 *priv, struct pci_dev *pcidev,
 
 	if (idx == 0) {
 		/* Setup Multipurpose Input/Output pins. */
-		setup_gpio(p);
+		setup_gpio(pcidev, p);
 
 		port->port.private_data = xr17v35x_register_gpio(pcidev);
 	}
-- 
2.12.3

[PATCH v5 02/11] gpio-exar/8250-exar: Do not even instantiate a GPIO device for Commtech cards

[Jan Kiszka]

Commtech adapters need the MPIOs for internal purposes, and the
gpio-exar driver already refused to pick them up. But there is actually
no point in even creating the underlying platform device.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
---
 drivers/gpio/gpio-exar.c            | 3 ---
 drivers/tty/serial/8250/8250_exar.c | 4 +++-
 2 files changed, 3 insertions(+), 4 deletions(-)

diff --git a/drivers/gpio/gpio-exar.c b/drivers/gpio/gpio-exar.c
index 081076771217..006a9a67c2a4 100644
--- a/drivers/gpio/gpio-exar.c
+++ b/drivers/gpio/gpio-exar.c
@@ -124,9 +124,6 @@ static int gpio_exar_probe(struct platform_device *pdev)
 	void __iomem *p;
 	int index, ret;
 
-	if (pcidev->vendor != PCI_VENDOR_ID_EXAR)
-		return -ENODEV;
-
 	/*
 	 * Map the pci device to get the register addresses.
 	 * We will need to read and write those registers to control
diff --git a/drivers/tty/serial/8250/8250_exar.c b/drivers/tty/serial/8250/8250_exar.c
index 8984e8b2d524..c29c7e675890 100644
--- a/drivers/tty/serial/8250/8250_exar.c
+++ b/drivers/tty/serial/8250/8250_exar.c
@@ -245,7 +245,9 @@ pci_xr17v35x_setup(struct exar8250 *priv, struct pci_dev *pcidev,
 		/* Setup Multipurpose Input/Output pins. */
 		setup_gpio(pcidev, p);
 
-		port->port.private_data = xr17v35x_register_gpio(pcidev);
+		if (pcidev->vendor == PCI_VENDOR_ID_EXAR)
+			port->port.private_data =
+				xr17v35x_register_gpio(pcidev);
 	}
 
 	return 0;
-- 
2.12.3

[PATCH v5 03/11] gpio-exar/8250-exar: Fix passing in of parent PCI device

[Jan Kiszka]

This fixes reloading of the GPIO driver for the same platform device
instance as created by the exar UART driver: First of all, the driver
sets drvdata to its own value during probing and does not restore the
original value on exit. But this won't help anyway as the core clears
drvdata after the driver left.

Set the platform device parent instead.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
---
 drivers/gpio/gpio-exar.c            | 2 +-
 drivers/tty/serial/8250/8250_exar.c | 3 ++-
 2 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/gpio/gpio-exar.c b/drivers/gpio/gpio-exar.c
index 006a9a67c2a4..da4550bb9939 100644
--- a/drivers/gpio/gpio-exar.c
+++ b/drivers/gpio/gpio-exar.c
@@ -119,7 +119,7 @@ static int exar_direction_input(struct gpio_chip *chip, unsigned int offset)
 
 static int gpio_exar_probe(struct platform_device *pdev)
 {
-	struct pci_dev *pcidev = platform_get_drvdata(pdev);
+	struct pci_dev *pcidev = to_pci_dev(pdev->dev.parent);
 	struct exar_gpio_chip *exar_gpio;
 	void __iomem *p;
 	int index, ret;
diff --git a/drivers/tty/serial/8250/8250_exar.c b/drivers/tty/serial/8250/8250_exar.c
index c29c7e675890..0f4b236d7e68 100644
--- a/drivers/tty/serial/8250/8250_exar.c
+++ b/drivers/tty/serial/8250/8250_exar.c
@@ -203,7 +203,8 @@ xr17v35x_register_gpio(struct pci_dev *pcidev)
 	if (!pdev)
 		return NULL;
 
-	platform_set_drvdata(pdev, pcidev);
+	pdev->dev.parent = &pcidev->dev;
+
 	if (platform_device_add(pdev) < 0) {
 		platform_device_put(pdev);
 		return NULL;
-- 
2.12.3

[PATCH v5 04/11] gpio: exar: Allocate resources on behalf of the platform device

[Jan Kiszka]

Do not allocate resources on behalf of the parent device but on our own.
Otherwise, cleanup does not properly work if gpio-exar is removed but
not the parent device.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
---
 drivers/gpio/gpio-exar.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/gpio/gpio-exar.c b/drivers/gpio/gpio-exar.c
index da4550bb9939..65126fa1e512 100644
--- a/drivers/gpio/gpio-exar.c
+++ b/drivers/gpio/gpio-exar.c
@@ -136,7 +136,7 @@ static int gpio_exar_probe(struct platform_device *pdev)
 	if (!p)
 		return -ENOMEM;
 
-	exar_gpio = devm_kzalloc(&pcidev->dev, sizeof(*exar_gpio), GFP_KERNEL);
+	exar_gpio = devm_kzalloc(&pdev->dev, sizeof(*exar_gpio), GFP_KERNEL);
 	if (!exar_gpio)
 		return -ENOMEM;
 
@@ -157,7 +157,7 @@ static int gpio_exar_probe(struct platform_device *pdev)
 	exar_gpio->regs = p;
 	exar_gpio->index = index;
 
-	ret = devm_gpiochip_add_data(&pcidev->dev,
+	ret = devm_gpiochip_add_data(&pdev->dev,
 				     &exar_gpio->gpio_chip, exar_gpio);
 	if (ret)
 		goto err_destroy;
-- 
2.12.3

[PATCH v5 05/11] gpio: exar: Fix iomap request

[Jan Kiszka]

The UART driver already maps the resource for us. Trying to do this here
only fails and leaves us with a non-working device.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
---
 drivers/gpio/gpio-exar.c | 10 +++-------
 1 file changed, 3 insertions(+), 7 deletions(-)

diff --git a/drivers/gpio/gpio-exar.c b/drivers/gpio/gpio-exar.c
index 65126fa1e512..b29890b143ce 100644
--- a/drivers/gpio/gpio-exar.c
+++ b/drivers/gpio/gpio-exar.c
@@ -125,14 +125,10 @@ static int gpio_exar_probe(struct platform_device *pdev)
 	int index, ret;
 
 	/*
-	 * Map the pci device to get the register addresses.
-	 * We will need to read and write those registers to control
-	 * the GPIO pins.
-	 * Using managed functions will save us from unmaping on exit.
-	 * As the device is enabled using managed functions by the
-	 * UART driver we can also use managed functions here.
+	 * The UART driver must have mapped region 0 prior to registering this
+	 * device - use it.
 	 */
-	p = pcim_iomap(pcidev, 0, 0);
+	p = pcim_iomap_table(pcidev)[0];
 	if (!p)
 		return -ENOMEM;
 
-- 
2.12.3

[PATCH v5 06/11] gpio: exar: Fix reading of directions and values

[Jan Kiszka]

First, the logic for translating a register bit to the return code of
exar_get_direction and exar_get_value were wrong. And second, there was
a flip regarding the register bank in exar_get_direction.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
---
 drivers/gpio/gpio-exar.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/gpio/gpio-exar.c b/drivers/gpio/gpio-exar.c
index b29890b143ce..f3585a184f39 100644
--- a/drivers/gpio/gpio-exar.c
+++ b/drivers/gpio/gpio-exar.c
@@ -68,7 +68,7 @@ static int exar_get(struct gpio_chip *chip, unsigned int reg)
 	value = readb(exar_gpio->regs + reg);
 	mutex_unlock(&exar_gpio->lock);
 
-	return !!value;
+	return value;
 }
 
 static int exar_get_direction(struct gpio_chip *chip, unsigned int offset)
@@ -78,7 +78,7 @@ static int exar_get_direction(struct gpio_chip *chip, unsigned int offset)
 	int val;
 
 	addr = bank ? EXAR_OFFSET_MPIOSEL_HI : EXAR_OFFSET_MPIOSEL_LO;
-	val = exar_get(chip, addr) >> (offset % 8);
+	val = exar_get(chip, addr) & BIT(offset % 8);
 
 	return !!val;
 }
@@ -89,8 +89,8 @@ static int exar_get_value(struct gpio_chip *chip, unsigned int offset)
 	unsigned int addr;
 	int val;
 
-	addr = bank ? EXAR_OFFSET_MPIOLVL_LO : EXAR_OFFSET_MPIOLVL_HI;
-	val = exar_get(chip, addr) >> (offset % 8);
+	addr = bank ? EXAR_OFFSET_MPIOLVL_HI : EXAR_OFFSET_MPIOLVL_LO;
+	val = exar_get(chip, addr) & BIT(offset % 8);
 
 	return !!val;
 }
-- 
2.12.3

[PATCH v5 07/11] gpio-exar/8250-exar: Rearrange gpiochip parenthood

[Jan Kiszka]

Set the parent of the exar gpiochip to its platform device, like other
gpiochips are doing it. In order to keep the relationship discoverable
for ACPI systems, set the platform device companion to the PCI device.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
---
 drivers/gpio/gpio-exar.c            | 2 +-
 drivers/tty/serial/8250/8250_exar.c | 2 ++
 2 files changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/gpio/gpio-exar.c b/drivers/gpio/gpio-exar.c
index f3585a184f39..1a629831d45b 100644
--- a/drivers/gpio/gpio-exar.c
+++ b/drivers/gpio/gpio-exar.c
@@ -142,7 +142,7 @@ static int gpio_exar_probe(struct platform_device *pdev)
 
 	sprintf(exar_gpio->name, "exar_gpio%d", index);
 	exar_gpio->gpio_chip.label = exar_gpio->name;
-	exar_gpio->gpio_chip.parent = &pcidev->dev;
+	exar_gpio->gpio_chip.parent = &pdev->dev;
 	exar_gpio->gpio_chip.direction_output = exar_direction_output;
 	exar_gpio->gpio_chip.direction_input = exar_direction_input;
 	exar_gpio->gpio_chip.get_direction = exar_get_direction;
diff --git a/drivers/tty/serial/8250/8250_exar.c b/drivers/tty/serial/8250/8250_exar.c
index 0f4b236d7e68..ee4b142f3ed0 100644
--- a/drivers/tty/serial/8250/8250_exar.c
+++ b/drivers/tty/serial/8250/8250_exar.c
@@ -9,6 +9,7 @@
  * it under the terms of the GNU General Public License as published by
  * the Free Software Foundation; either version 2 of the License.
  */
+#include <linux/acpi.h>
 #include <linux/io.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
@@ -204,6 +205,7 @@ xr17v35x_register_gpio(struct pci_dev *pcidev)
 		return NULL;
 
 	pdev->dev.parent = &pcidev->dev;
+	ACPI_COMPANION_SET(&pdev->dev, ACPI_COMPANION(&pcidev->dev));
 
 	if (platform_device_add(pdev) < 0) {
 		platform_device_put(pdev);
-- 
2.12.3

[PATCH v5 08/11] serial: exar: Factor out platform hooks

[Jan Kiszka]

This prepares the addition of IOT2040 platform support by preparing the
needed setup and rs485_config hooks.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
---
 drivers/tty/serial/8250/8250_exar.c | 32 +++++++++++++++++++++++++++-----
 1 file changed, 27 insertions(+), 5 deletions(-)

diff --git a/drivers/tty/serial/8250/8250_exar.c b/drivers/tty/serial/8250/8250_exar.c
index ee4b142f3ed0..1106f1f58c77 100644
--- a/drivers/tty/serial/8250/8250_exar.c
+++ b/drivers/tty/serial/8250/8250_exar.c
@@ -63,6 +63,11 @@
 
 struct exar8250;
 
+struct exar8250_platform {
+	int (*rs485_config)(struct uart_port *, struct serial_rs485 *);
+	int (*register_gpio)(struct pci_dev *, struct uart_8250_port *);
+};
+
 /**
  * struct exar8250_board - board information
  * @num_ports: number of serial ports
@@ -196,7 +201,7 @@ static void setup_gpio(struct pci_dev *pcidev, u8 __iomem *p)
 }
 
 static void *
-xr17v35x_register_gpio(struct pci_dev *pcidev)
+__xr17v35x_register_gpio(struct pci_dev *pcidev)
 {
 	struct platform_device *pdev;
 
@@ -215,17 +220,36 @@ xr17v35x_register_gpio(struct pci_dev *pcidev)
 	return pdev;
 }
 
+static int xr17v35x_register_gpio(struct pci_dev *pcidev,
+				  struct uart_8250_port *port)
+{
+	if (pcidev->vendor == PCI_VENDOR_ID_EXAR)
+		port->port.private_data =
+			__xr17v35x_register_gpio(pcidev);
+
+	return 0;
+}
+
+static const struct exar8250_platform exar8250_default_platform = {
+	.register_gpio = xr17v35x_register_gpio,
+};
+
 static int
 pci_xr17v35x_setup(struct exar8250 *priv, struct pci_dev *pcidev,
 		   struct uart_8250_port *port, int idx)
 {
 	const struct exar8250_board *board = priv->board;
+	const struct exar8250_platform *platform;
 	unsigned int offset = idx * 0x400;
 	unsigned int baud = 7812500;
 	u8 __iomem *p;
 	int ret;
 
+	platform = &exar8250_default_platform;
+
 	port->port.uartclk = baud * 16;
+	port->port.rs485_config = platform->rs485_config;
+
 	/*
 	 * Setup the uart clock for the devices on expansion slot to
 	 * half the clock speed of the main chip (which is 125MHz)
@@ -248,12 +272,10 @@ pci_xr17v35x_setup(struct exar8250 *priv, struct pci_dev *pcidev,
 		/* Setup Multipurpose Input/Output pins. */
 		setup_gpio(pcidev, p);
 
-		if (pcidev->vendor == PCI_VENDOR_ID_EXAR)
-			port->port.private_data =
-				xr17v35x_register_gpio(pcidev);
+		ret = platform->register_gpio(pcidev, port);
 	}
 
-	return 0;
+	return ret;
 }
 
 static void pci_xr17v35x_exit(struct pci_dev *pcidev)
-- 
2.12.3

[PATCH v5 09/11] platform: Accept const properties

[Jan Kiszka]

Aligns us with device_add_properties, the function we call.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
---
 drivers/base/platform.c         | 2 +-
 include/linux/platform_device.h | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/base/platform.c b/drivers/base/platform.c
index a102152301c8..71ea6f4d33c2 100644
--- a/drivers/base/platform.c
+++ b/drivers/base/platform.c
@@ -344,7 +344,7 @@ EXPORT_SYMBOL_GPL(platform_device_add_data);
  * platform device is released.
  */
 int platform_device_add_properties(struct platform_device *pdev,
-				   struct property_entry *properties)
+				   const struct property_entry *properties)
 {
 	return device_add_properties(&pdev->dev, properties);
 }
diff --git a/include/linux/platform_device.h b/include/linux/platform_device.h
index 98c2a7c7108e..49f634d96118 100644
--- a/include/linux/platform_device.h
+++ b/include/linux/platform_device.h
@@ -172,7 +172,7 @@ extern int platform_device_add_resources(struct platform_device *pdev,
 extern int platform_device_add_data(struct platform_device *pdev,
 				    const void *data, size_t size);
 extern int platform_device_add_properties(struct platform_device *pdev,
-					  struct property_entry *properties);
+				const struct property_entry *properties);
 extern int platform_device_add(struct platform_device *pdev);
 extern void platform_device_del(struct platform_device *pdev);
 extern void platform_device_put(struct platform_device *pdev);
-- 
2.12.3

[PATCH v5 10/11] gpio-exar/8250-exar: Make set of exported GPIOs configurable

[Jan Kiszka]

On the SIMATIC, IOT2040 only a single pin is exportable as GPIO, the
rest is required to operate the UART. To allow modeling this case,
expand the platform device data structure to specify a (consecutive) pin
subset for exporting by the gpio-exar driver.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
---
 drivers/gpio/gpio-exar.c            | 52 +++++++++++++++++++++----------------
 drivers/tty/serial/8250/8250_exar.c | 15 ++++++++---
 2 files changed, 41 insertions(+), 26 deletions(-)

diff --git a/drivers/gpio/gpio-exar.c b/drivers/gpio/gpio-exar.c
index 1a629831d45b..220e93ed9111 100644
--- a/drivers/gpio/gpio-exar.c
+++ b/drivers/gpio/gpio-exar.c
@@ -31,6 +31,7 @@ struct exar_gpio_chip {
 	int index;
 	void __iomem *regs;
 	char name[20];
+	unsigned int first_pin;
 };
 
 static void exar_update(struct gpio_chip *chip, unsigned int reg, int val,
@@ -51,11 +52,12 @@ static void exar_update(struct gpio_chip *chip, unsigned int reg, int val,
 static int exar_set_direction(struct gpio_chip *chip, int direction,
 			      unsigned int offset)
 {
-	unsigned int bank = offset / 8;
-	unsigned int addr;
+	struct exar_gpio_chip *exar_gpio = gpiochip_get_data(chip);
+	unsigned int addr = (offset + exar_gpio->first_pin) / 8 ?
+		EXAR_OFFSET_MPIOSEL_HI : EXAR_OFFSET_MPIOSEL_LO;
+	unsigned int bit  = (offset + exar_gpio->first_pin) % 8;
 
-	addr = bank ? EXAR_OFFSET_MPIOSEL_HI : EXAR_OFFSET_MPIOSEL_LO;
-	exar_update(chip, addr, direction, offset % 8);
+	exar_update(chip, addr, direction, bit);
 	return 0;
 }
 
@@ -73,36 +75,33 @@ static int exar_get(struct gpio_chip *chip, unsigned int reg)
 
 static int exar_get_direction(struct gpio_chip *chip, unsigned int offset)
 {
-	unsigned int bank = offset / 8;
-	unsigned int addr;
-	int val;
-
-	addr = bank ? EXAR_OFFSET_MPIOSEL_HI : EXAR_OFFSET_MPIOSEL_LO;
-	val = exar_get(chip, addr) & BIT(offset % 8);
+	struct exar_gpio_chip *exar_gpio = gpiochip_get_data(chip);
+	unsigned int addr = (offset + exar_gpio->first_pin) / 8 ?
+		EXAR_OFFSET_MPIOSEL_HI : EXAR_OFFSET_MPIOSEL_LO;
+	unsigned int bit  = (offset + exar_gpio->first_pin) % 8;
 
-	return !!val;
+	return !!(exar_get(chip, addr) & BIT(bit));
 }
 
 static int exar_get_value(struct gpio_chip *chip, unsigned int offset)
 {
-	unsigned int bank = offset / 8;
-	unsigned int addr;
-	int val;
-
-	addr = bank ? EXAR_OFFSET_MPIOLVL_HI : EXAR_OFFSET_MPIOLVL_LO;
-	val = exar_get(chip, addr) & BIT(offset % 8);
+	struct exar_gpio_chip *exar_gpio = gpiochip_get_data(chip);
+	unsigned int addr = (offset + exar_gpio->first_pin) / 8 ?
+		EXAR_OFFSET_MPIOLVL_HI : EXAR_OFFSET_MPIOLVL_LO;
+	unsigned int bit  = (offset + exar_gpio->first_pin) % 8;
 
-	return !!val;
+	return !!(exar_get(chip, addr) & BIT(bit));
 }
 
 static void exar_set_value(struct gpio_chip *chip, unsigned int offset,
 			   int value)
 {
-	unsigned int bank = offset / 8;
-	unsigned int addr;
+	struct exar_gpio_chip *exar_gpio = gpiochip_get_data(chip);
+	unsigned int addr = (offset + exar_gpio->first_pin) / 8 ?
+		EXAR_OFFSET_MPIOLVL_HI : EXAR_OFFSET_MPIOLVL_LO;
+	unsigned int bit  = (offset + exar_gpio->first_pin) % 8;
 
-	addr = bank ? EXAR_OFFSET_MPIOLVL_HI : EXAR_OFFSET_MPIOLVL_LO;
-	exar_update(chip, addr, value, offset % 8);
+	exar_update(chip, addr, value, bit);
 }
 
 static int exar_direction_output(struct gpio_chip *chip, unsigned int offset,
@@ -121,6 +120,7 @@ static int gpio_exar_probe(struct platform_device *pdev)
 {
 	struct pci_dev *pcidev = to_pci_dev(pdev->dev.parent);
 	struct exar_gpio_chip *exar_gpio;
+	u32 first_pin, ngpios;
 	void __iomem *p;
 	int index, ret;
 
@@ -132,6 +132,11 @@ static int gpio_exar_probe(struct platform_device *pdev)
 	if (!p)
 		return -ENOMEM;
 
+	if (device_property_read_u32(&pdev->dev, "gpio-exar,first-pin",
+				     &first_pin) < 0 ||
+	    device_property_read_u32(&pdev->dev, "ngpios", &ngpios) < 0)
+		return -EINVAL;
+
 	exar_gpio = devm_kzalloc(&pdev->dev, sizeof(*exar_gpio), GFP_KERNEL);
 	if (!exar_gpio)
 		return -ENOMEM;
@@ -149,9 +154,10 @@ static int gpio_exar_probe(struct platform_device *pdev)
 	exar_gpio->gpio_chip.get = exar_get_value;
 	exar_gpio->gpio_chip.set = exar_set_value;
 	exar_gpio->gpio_chip.base = -1;
-	exar_gpio->gpio_chip.ngpio = 16;
+	exar_gpio->gpio_chip.ngpio = ngpios;
 	exar_gpio->regs = p;
 	exar_gpio->index = index;
+	exar_gpio->first_pin = first_pin;
 
 	ret = devm_gpiochip_add_data(&pdev->dev,
 				     &exar_gpio->gpio_chip, exar_gpio);
diff --git a/drivers/tty/serial/8250/8250_exar.c b/drivers/tty/serial/8250/8250_exar.c
index 1106f1f58c77..bd0e40e869b8 100644
--- a/drivers/tty/serial/8250/8250_exar.c
+++ b/drivers/tty/serial/8250/8250_exar.c
@@ -14,6 +14,7 @@
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/pci.h>
+#include <linux/property.h>
 #include <linux/serial_core.h>
 #include <linux/serial_reg.h>
 #include <linux/slab.h>
@@ -201,7 +202,8 @@ static void setup_gpio(struct pci_dev *pcidev, u8 __iomem *p)
 }
 
 static void *
-__xr17v35x_register_gpio(struct pci_dev *pcidev)
+__xr17v35x_register_gpio(struct pci_dev *pcidev,
+			 const struct property_entry *properties)
 {
 	struct platform_device *pdev;
 
@@ -212,7 +214,8 @@ __xr17v35x_register_gpio(struct pci_dev *pcidev)
 	pdev->dev.parent = &pcidev->dev;
 	ACPI_COMPANION_SET(&pdev->dev, ACPI_COMPANION(&pcidev->dev));
 
-	if (platform_device_add(pdev) < 0) {
+	if (platform_device_add_properties(pdev, properties) < 0 ||
+	    platform_device_add(pdev) < 0) {
 		platform_device_put(pdev);
 		return NULL;
 	}
@@ -220,12 +223,18 @@ __xr17v35x_register_gpio(struct pci_dev *pcidev)
 	return pdev;
 }
 
+static const struct property_entry exar_gpio_properties[] = {
+	PROPERTY_ENTRY_U32("gpio-exar,first-pin", 0),
+	PROPERTY_ENTRY_U32("ngpios", 16),
+	{ }
+};
+
 static int xr17v35x_register_gpio(struct pci_dev *pcidev,
 				  struct uart_8250_port *port)
 {
 	if (pcidev->vendor == PCI_VENDOR_ID_EXAR)
 		port->port.private_data =
-			__xr17v35x_register_gpio(pcidev);
+			__xr17v35x_register_gpio(pcidev, exar_gpio_properties);
 
 	return 0;
 }
-- 
2.12.3

[PATCH v5 11/11] serial: exar: Add support for IOT2040 device

[Jan Kiszka]

This implements the setup of RS232 and the switch-over to RS485 or RS422
for the Siemens IOT2040. That uses an EXAR XR17V352 with external logic
to switch between the different modes. The external logic is controlled
via MPIO pins of the EXAR controller.

Only pin 10 can be exported as GPIO on the IOT2040. It is connected to
an LED.

As the XR17V352 used on the IOT2040 is not equipped with an external
EEPROM, it cannot present itself as IOT2040-variant via subvendor/
subdevice IDs. Thus, we have to check via DMI for the target platform.

Co-developed with Sascha Weisenberger.

Signed-off-by: Sascha Weisenberger <sascha.weisenberger@siemens.com>
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
---
 drivers/tty/serial/8250/8250_exar.c | 129 +++++++++++++++++++++++++++++++++++-
 1 file changed, 128 insertions(+), 1 deletion(-)

diff --git a/drivers/tty/serial/8250/8250_exar.c b/drivers/tty/serial/8250/8250_exar.c
index bd0e40e869b8..4154601b1d03 100644
--- a/drivers/tty/serial/8250/8250_exar.c
+++ b/drivers/tty/serial/8250/8250_exar.c
@@ -10,6 +10,7 @@
  * the Free Software Foundation; either version 2 of the License.
  */
 #include <linux/acpi.h>
+#include <linux/dmi.h>
 #include <linux/io.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
@@ -62,6 +63,43 @@
 #define UART_EXAR_MPIOSEL_15_8	0x99	/* MPIOSEL[15:8] */
 #define UART_EXAR_MPIOOD_15_8	0x9a	/* MPIOOD[15:8] */
 
+#define UART_EXAR_RS485_DLY(x)	((x) << 4)
+
+/*
+ * IOT2040 MPIO wiring semantics:
+ *
+ * MPIO		Port	Function
+ * ----		----	--------
+ * 0		2 	Mode bit 0
+ * 1		2	Mode bit 1
+ * 2		2	Terminate bus
+ * 3		-	<reserved>
+ * 4		3	Mode bit 0
+ * 5		3	Mode bit 1
+ * 6		3	Terminate bus
+ * 7		-	<reserved>
+ * 8		2	Enable
+ * 9		3	Enable
+ * 10		-	Red LED
+ * 11..15	-	<unused>
+ */
+
+/* IOT2040 MPIOs 0..7 */
+#define IOT2040_UART_MODE_RS232		0x01
+#define IOT2040_UART_MODE_RS485		0x02
+#define IOT2040_UART_MODE_RS422		0x03
+#define IOT2040_UART_TERMINATE_BUS	0x04
+
+#define IOT2040_UART1_MASK		0x0f
+#define IOT2040_UART2_SHIFT		4
+
+#define IOT2040_UARTS_DEFAULT_MODE	0x11	/* both RS232 */
+#define IOT2040_UARTS_GPIO_LO_MODE	0x88	/* reserved pins as input */
+
+/* IOT2040 MPIOs 8..15 */
+#define IOT2040_UARTS_ENABLE		0x03
+#define IOT2040_UARTS_GPIO_HI_MODE	0xF8	/* enable & LED as outputs */
+
 struct exar8250;
 
 struct exar8250_platform {
@@ -243,18 +281,107 @@ static const struct exar8250_platform exar8250_default_platform = {
 	.register_gpio = xr17v35x_register_gpio,
 };
 
+static int iot2040_rs485_config(struct uart_port *port,
+				struct serial_rs485 *rs485)
+{
+	bool is_rs485 = !!(rs485->flags & SER_RS485_ENABLED);
+	u8 __iomem *p = port->membase;
+	u8 mask = IOT2040_UART1_MASK;
+	u8 mode, value;
+
+	if (is_rs485) {
+		if (rs485->flags & SER_RS485_RX_DURING_TX)
+			mode = IOT2040_UART_MODE_RS422;
+		else
+			mode = IOT2040_UART_MODE_RS485;
+
+		if (rs485->flags & SER_RS485_TERMINATE_BUS)
+			mode |= IOT2040_UART_TERMINATE_BUS;
+	} else {
+		mode = IOT2040_UART_MODE_RS232;
+	}
+
+	if (port->line == 3) {
+		mask <<= IOT2040_UART2_SHIFT;
+		mode <<= IOT2040_UART2_SHIFT;
+	}
+
+	value = readb(p + UART_EXAR_MPIOLVL_7_0);
+	value &= ~mask;
+	value |= mode;
+	writeb(value, p + UART_EXAR_MPIOLVL_7_0);
+
+	value = readb(p + UART_EXAR_FCTR);
+	if (is_rs485)
+		value |= UART_FCTR_EXAR_485;
+	else
+		value &= ~UART_FCTR_EXAR_485;
+	writeb(value, p + UART_EXAR_FCTR);
+
+	if (is_rs485)
+		writeb(UART_EXAR_RS485_DLY(4), p + UART_MSR);
+
+	port->rs485 = *rs485;
+
+	return 0;
+}
+
+static const struct property_entry iot2040_gpio_properties[] = {
+	PROPERTY_ENTRY_U32("gpio-exar,first-pin", 10),
+	PROPERTY_ENTRY_U32("ngpios", 1),
+	{ }
+};
+
+static int iot2040_register_gpio(struct pci_dev *pcidev,
+			      struct uart_8250_port *port)
+{
+	u8 __iomem *p = port->port.membase;
+
+	writeb(IOT2040_UARTS_DEFAULT_MODE, p + UART_EXAR_MPIOLVL_7_0);
+	writeb(IOT2040_UARTS_GPIO_LO_MODE, p + UART_EXAR_MPIOSEL_7_0);
+	writeb(IOT2040_UARTS_ENABLE, p + UART_EXAR_MPIOLVL_15_8);
+	writeb(IOT2040_UARTS_GPIO_HI_MODE, p + UART_EXAR_MPIOSEL_15_8);
+
+	port->port.private_data =
+		__xr17v35x_register_gpio(pcidev, iot2040_gpio_properties);
+
+	return 0;
+}
+
+static const struct exar8250_platform iot2040_platform = {
+	.rs485_config = iot2040_rs485_config,
+	.register_gpio = iot2040_register_gpio,
+};
+
+static const struct dmi_system_id exar_platforms[] = {
+	{
+		.matches = {
+			DMI_EXACT_MATCH(DMI_BOARD_NAME, "SIMATIC IOT2000"),
+			DMI_EXACT_MATCH(DMI_BOARD_ASSET_TAG,
+					"6ES7647-0AA00-1YA2"),
+		},
+		.driver_data = (void *)&iot2040_platform,
+	},
+	{}
+};
+
 static int
 pci_xr17v35x_setup(struct exar8250 *priv, struct pci_dev *pcidev,
 		   struct uart_8250_port *port, int idx)
 {
 	const struct exar8250_board *board = priv->board;
 	const struct exar8250_platform *platform;
+	const struct dmi_system_id *dmi_match;
 	unsigned int offset = idx * 0x400;
 	unsigned int baud = 7812500;
 	u8 __iomem *p;
 	int ret;
 
-	platform = &exar8250_default_platform;
+	dmi_match = dmi_first_match(exar_platforms);
+	if (dmi_match)
+		platform = dmi_match->driver_data;
+	else
+		platform = &exar8250_default_platform;
 
 	port->port.uartclk = baud * 16;
 	port->port.rs485_config = platform->rs485_config;
-- 
2.12.3

Re: [PATCH v5 10/11] gpio-exar/8250-exar: Make set of exported GPIOs configurable

[Andy Shevchenko]

On Fri, Jun 2, 2017 at 10:28 AM, Jan Kiszka <jan.kiszka@siemens.com> wrote:
> On the SIMATIC, IOT2040 only a single pin is exportable as GPIO, the
> rest is required to operate the UART. To allow modeling this case,
> expand the platform device data structure to specify a (consecutive) pin
> subset for exporting by the gpio-exar driver.

> +       if (device_property_read_u32(&pdev->dev, "gpio-exar,first-pin",
> +                                    &first_pin) < 0 ||
> +           device_property_read_u32(&pdev->dev, "ngpios", &ngpios) < 0)
> +               return -EINVAL;

You shadow an error.

Please use
ret = device_property_...;
if (ret)
 return ret;

ret = ...
...

Moreover, I missed how you named first property, I would go rather
with "linux," prefix to show that is _internal_ / Linux only property.

Perhaps something like "linux,first-pin" ?

-- 
With Best Regards,
Andy Shevchenko

Re: [PATCH v5 01/11] serial: exar: Leave MPIOs as output for Commtech adapters

[Linus Walleij]

On Fri, Jun 2, 2017 at 9:28 AM, Jan Kiszka <jan.kiszka@siemens.com> wrote:

> Commtech adapters apparently need the original setting as outputs, see
> https://marc.info/?l=linux-gpio&m=149557425201323&w=2. Account for that.
>
> Fixes: 7dea8165f1d6 ("serial: exar: Preconfigure xr17v35x MPIOs as output")
> Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
> Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>

Reviewed-by: Linus Walleij <linus.walleij@linaro.org>

Greg can you pick this up for fixes?

Yours,
Linus Walleij

Re: [PATCH v5 03/11] gpio-exar/8250-exar: Fix passing in of parent PCI device

[Linus Walleij]

On Fri, Jun 2, 2017 at 9:28 AM, Jan Kiszka <jan.kiszka@siemens.com> wrote:

> This fixes reloading of the GPIO driver for the same platform device
> instance as created by the exar UART driver: First of all, the driver
> sets drvdata to its own value during probing and does not restore the
> original value on exit. But this won't help anyway as the core clears
> drvdata after the driver left.
>
> Set the platform device parent instead.
>
> Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
> Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
> Acked-by: Linus Walleij <linus.walleij@linaro.org>

If I get Gregs ACK on this I can merge patches 2-11 through the
GPIO tree.

Yours,
Linus Walleij

Re: [PATCH v5 03/11] gpio-exar/8250-exar: Fix passing in of parent PCI device

[Jan Kiszka]

On 2017-06-09 09:21, Linus Walleij wrote:
> On Fri, Jun 2, 2017 at 9:28 AM, Jan Kiszka <jan.kiszka@siemens.com> wrote:
> 
>> This fixes reloading of the GPIO driver for the same platform device
>> instance as created by the exar UART driver: First of all, the driver
>> sets drvdata to its own value during probing and does not restore the
>> original value on exit. But this won't help anyway as the core clears
>> drvdata after the driver left.
>>
>> Set the platform device parent instead.
>>
>> Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
>> Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
>> Acked-by: Linus Walleij <linus.walleij@linaro.org>
> 
> If I get Gregs ACK on this I can merge patches 2-11 through the
> GPIO tree.
> 

Patch 10 needs an update, Andy had remarks. I need to resync and send it
- there will be v6 soon.

Thanks,
Jan

-- 
Siemens AG, Corporate Technology, CT RDA ITP SES-DE
Corporate Competence Center Embedded Linux

Re: [PATCH v5 03/11] gpio-exar/8250-exar: Fix passing in of parent PCI device

[Greg Kroah-Hartman]

On Fri, Jun 02, 2017 at 09:28:46AM +0200, Jan Kiszka wrote:
> This fixes reloading of the GPIO driver for the same platform device
> instance as created by the exar UART driver: First of all, the driver
> sets drvdata to its own value during probing and does not restore the
> original value on exit. But this won't help anyway as the core clears
> drvdata after the driver left.
> 
> Set the platform device parent instead.
> 
> Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
> Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
> Acked-by: Linus Walleij <linus.walleij@linaro.org>

Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Re: [PATCH v5 01/11] serial: exar: Leave MPIOs as output for Commtech adapters

[Greg Kroah-Hartman]

On Fri, Jun 09, 2017 at 09:20:43AM +0200, Linus Walleij wrote:
> On Fri, Jun 2, 2017 at 9:28 AM, Jan Kiszka <jan.kiszka@siemens.com> wrote:
> 
> > Commtech adapters apparently need the original setting as outputs, see
> > https://marc.info/?l=linux-gpio&m=149557425201323&w=2. Account for that.
> >
> > Fixes: 7dea8165f1d6 ("serial: exar: Preconfigure xr17v35x MPIOs as output")
> > Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
> > Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
> 
> Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
> 
> Greg can you pick this up for fixes?

Ok, will do, thanks.

greg k-h