gpio: add sl28cpld driver

The gpio block is part of the sl28cpld sl28cpld management controller.
There are three different flavors: the usual input and output where the
direction is configurable, but also input only and output only variants.

Signed-off-by: Michael Walle <michael@walle.cc>
[Rebased]
Signed-off-by: Priyanka Jain <priyanka.jain@nxp.com>

diff --git a/MAINTAINERS b/MAINTAINERS
index 989ea41..0f39bc6 100644 (file)
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -1164,6 +1164,7 @@ F:        arch/sh/
 SL28CLPD
 M:     Michael Walle <michael@walle.cc>
 S:     Maintained
+F:     drivers/gpio/sl28cpld-gpio.c
 F:     drivers/misc/sl28cpld.c
 F:     drivers/watchdog/sl28cpld-wdt.c
 

diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index 8d0e47c..522dfc1 100644 (file)
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -544,4 +544,10 @@ config ZYNQMP_GPIO_MODEPIN
          are accessed using xilinx firmware. In modepin register, [3:0] bits
          set direction, [7:4] bits read IO, [11:8] bits set/clear IO.
 
+config SL28CPLD_GPIO
+       bool "Kontron sl28cpld GPIO driver"
+       depends on DM_GPIO && SL28CPLD
+       help
+         Support GPIO access on Kontron sl28cpld board management controllers.
+
 endif

diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
index 63e9be6..33f7d41 100644 (file)
--- a/drivers/gpio/Makefile
+++ b/drivers/gpio/Makefile
@@ -70,4 +70,5 @@ obj-$(CONFIG_NX_GPIO)         += nx_gpio.o
 obj-$(CONFIG_SIFIVE_GPIO)      += sifive-gpio.o
 obj-$(CONFIG_NOMADIK_GPIO)     += nmk_gpio.o
 obj-$(CONFIG_MAX7320_GPIO)     += max7320_gpio.o
+obj-$(CONFIG_SL28CPLD_GPIO)    += sl28cpld-gpio.o
 obj-$(CONFIG_ZYNQMP_GPIO_MODEPIN)      += zynqmp_gpio_modepin.o

diff --git a/drivers/gpio/sl28cpld-gpio.c b/drivers/gpio/sl28cpld-gpio.c
new file mode 100644 (file)
index 0000000..700fc3d
--- /dev/null
+++ b/drivers/gpio/sl28cpld-gpio.c
@@ -0,0 +1,165 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * GPIO driver for the sl28cpld
+ *
+ * Copyright (c) 2021 Michael Walle <michael@walle.cc>
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <asm/gpio.h>
+#include <sl28cpld.h>
+
+/* GPIO flavor */
+#define SL28CPLD_GPIO_DIR      0x00
+#define SL28CPLD_GPIO_OUT      0x01
+#define SL28CPLD_GPIO_IN       0x02
+
+/* input-only flavor */
+#define SL28CPLD_GPI_IN                0x00
+
+/* output-only flavor */
+#define SL28CPLD_GPO_OUT       0x00
+
+enum {
+       SL28CPLD_GPIO,
+       SL28CPLD_GPI,
+       SL28CPLD_GPO,
+};
+
+static int sl28cpld_gpio_get_value(struct udevice *dev, unsigned int gpio)
+{
+       ulong type = dev_get_driver_data(dev);
+       int val, reg;
+
+       switch (type) {
+       case SL28CPLD_GPIO:
+               reg = SL28CPLD_GPIO_IN;
+               break;
+       case SL28CPLD_GPI:
+               reg = SL28CPLD_GPI_IN;
+               break;
+       case SL28CPLD_GPO:
+               /* we are output only, thus just return the output value */
+               reg = SL28CPLD_GPO_OUT;
+               break;
+       default:
+               return -EINVAL;
+       }
+
+       val = sl28cpld_read(dev, reg);
+
+       return val < 0 ? val : !!(val & BIT(gpio));
+}
+
+static int sl28cpld_gpio_set_value(struct udevice *dev, unsigned int gpio,
+                                  int value)
+{
+       ulong type = dev_get_driver_data(dev);
+       uint reg;
+
+       switch (type) {
+       case SL28CPLD_GPIO:
+               reg = SL28CPLD_GPIO_OUT;
+               break;
+       case SL28CPLD_GPO:
+               reg = SL28CPLD_GPO_OUT;
+               break;
+       case SL28CPLD_GPI:
+       default:
+               return -EINVAL;
+       }
+
+       if (value)
+               return sl28cpld_update(dev, reg, 0, BIT(gpio));
+       else
+               return sl28cpld_update(dev, reg, BIT(gpio), 0);
+}
+
+static int sl28cpld_gpio_direction_input(struct udevice *dev, unsigned int gpio)
+{
+       ulong type = dev_get_driver_data(dev);
+
+       switch (type) {
+       case SL28CPLD_GPI:
+               return 0;
+       case SL28CPLD_GPIO:
+               return sl28cpld_update(dev, SL28CPLD_GPIO_DIR, BIT(gpio), 0);
+       case SL28CPLD_GPO:
+       default:
+               return -EINVAL;
+       }
+}
+
+static int sl28cpld_gpio_direction_output(struct udevice *dev,
+                                         unsigned int gpio, int value)
+{
+       ulong type = dev_get_driver_data(dev);
+       int ret;
+
+       /* set_value() will report an error if we are input-only */
+       ret = sl28cpld_gpio_set_value(dev, gpio, value);
+       if (ret)
+               return ret;
+
+       if (type == SL28CPLD_GPIO)
+               return sl28cpld_update(dev, SL28CPLD_GPIO_DIR, 0, BIT(gpio));
+
+       return 0;
+}
+
+static int sl28cpld_gpio_get_function(struct udevice *dev, unsigned int gpio)
+{
+       ulong type = dev_get_driver_data(dev);
+       int val;
+
+       switch (type) {
+       case SL28CPLD_GPIO:
+               val = sl28cpld_read(dev, SL28CPLD_GPIO_DIR);
+               if (val < 0)
+                       return val;
+               if (val & BIT(gpio))
+                       return GPIOF_OUTPUT;
+               else
+                       return GPIOF_INPUT;
+       case SL28CPLD_GPI:
+               return GPIOF_INPUT;
+       case SL28CPLD_GPO:
+               return GPIOF_OUTPUT;
+       default:
+               return -EINVAL;
+       }
+}
+
+static const struct dm_gpio_ops sl28cpld_gpio_ops = {
+       .direction_input = sl28cpld_gpio_direction_input,
+       .direction_output = sl28cpld_gpio_direction_output,
+       .get_value = sl28cpld_gpio_get_value,
+       .set_value = sl28cpld_gpio_set_value,
+       .get_function = sl28cpld_gpio_get_function,
+};
+
+static int sl28cpld_gpio_probe(struct udevice *dev)
+{
+       struct gpio_dev_priv *uc_priv = dev_get_uclass_priv(dev);
+
+       uc_priv->gpio_count = 8;
+       uc_priv->bank_name = dev_read_name(dev);
+
+       return 0;
+}
+
+static const struct udevice_id sl28cpld_gpio_ids[] = {
+       { .compatible = "kontron,sl28cpld-gpio", .data = SL28CPLD_GPIO},
+       { .compatible = "kontron,sl28cpld-gpo", .data = SL28CPLD_GPO},
+       { .compatible = "kontron,sl28cpld-gpi", .data = SL28CPLD_GPI},
+       { }
+};
+
+U_BOOT_DRIVER(sl28cpld_gpio) = {
+       .name   = "sl28cpld_gpio",
+       .id     = UCLASS_GPIO,
+       .of_match = sl28cpld_gpio_ids,
+       .probe  = sl28cpld_gpio_probe,
+       .ops    = &sl28cpld_gpio_ops,
+};