This driver allows to use the CBUS pins, e.g. CBUS 0-3 on FT232R
type of devices. Note that the pins need to be configured first
by using I/O mode signal option in the EEPROM. This is _not_ the
factory default configuration of any of the four pins.
See also FTDI's Application Note AN_232R-01.
Signed-off-by: Stefan Agner ste...@agner.ch
---
drivers/gpio/Kconfig | 10 +++
drivers/gpio/Makefile | 1 +
drivers/gpio/gpio-ftdi-cbus.c | 167 ++
drivers/usb/serial/ftdi_sio.c | 16
4 files changed, 194 insertions(+)
create mode 100644 drivers/gpio/gpio-ftdi-cbus.c
diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index caefe80..450ba9f 100644
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -975,6 +975,16 @@ endmenu
menu USB GPIO expanders
depends on USB
+config GPIO_FTDI_CBUS
+ tristate FTDI FT232R CBUS bitmode GPIO support
+ depends on USB_SERIAL_FTDI_SIO
+ help
+ Say yes to use up to four CBUS pins on FT232R type of devices
+ Note that the pins need to be configured in EEPROM using to
+ I/O mode signal option first. The factory configuration
+ does not ship with this signal option set for any of the four
+ supported CBUS pins.
+
config GPIO_VIPERBOARD
tristate Viperboard GPIO a b support
depends on MFD_VIPERBOARD USB
diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
index f71bb97..a5d661b4 100644
--- a/drivers/gpio/Makefile
+++ b/drivers/gpio/Makefile
@@ -33,6 +33,7 @@ obj-$(CONFIG_GPIO_DWAPB) += gpio-dwapb.o
obj-$(CONFIG_GPIO_EM) += gpio-em.o
obj-$(CONFIG_GPIO_EP93XX) += gpio-ep93xx.o
obj-$(CONFIG_GPIO_F7188X) += gpio-f7188x.o
+obj-$(CONFIG_GPIO_FTDI_CBUS) += gpio-ftdi-cbus.o
obj-$(CONFIG_GPIO_GE_FPGA) += gpio-ge.o
obj-$(CONFIG_GPIO_GRGPIO) += gpio-grgpio.o
obj-$(CONFIG_GPIO_ICH) += gpio-ich.o
diff --git a/drivers/gpio/gpio-ftdi-cbus.c b/drivers/gpio/gpio-ftdi-cbus.c
new file mode 100644
index 000..3a4dc46
--- /dev/null
+++ b/drivers/gpio/gpio-ftdi-cbus.c
@@ -0,0 +1,167 @@
+/*
+ * gpiolib support for FTDI SIO chips supporting CBUS GPIO's (FT232R class)
+ *
+ * Copyright 2015 Stefan Agner
+ *
+ * Author: Stefan Agner ste...@agner.ch
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2 of the License, or (at your
+ * option) any later version.
+ *
+ * Note: To use the GPIOs on CBUS the signal option need to be set to
+ * I/O mode in EEPROM!
+ */
+
+#include linux/kernel.h
+#include linux/slab.h
+#include linux/module.h
+#include linux/gpio.h
+#include linux/platform_device.h
+#include linux/seq_file.h
+#include linux/regmap.h
+
+#include linux/usb/ftdi_sio.h
+
+struct ftdi_cbus_gpio {
+ struct usb_serial_port *port;
+ struct gpio_chip gpio_chip;
+ u8 cbus_mask;
+};
+
+static inline struct ftdi_cbus_gpio *to_ftdi_cbus_gpio(struct gpio_chip *chip)
+{
+ return container_of(chip, struct ftdi_cbus_gpio, gpio_chip);
+}
+
+static int ftdi_cbus_gpio_direction_input(struct gpio_chip *chip,
+ unsigned offset)
+{
+ struct ftdi_cbus_gpio *fcg = to_ftdi_cbus_gpio(chip);
+
+ fcg-cbus_mask = ~((1 offset) 4);
+
+ return ftdi_sio_set_bitmode(fcg-port, fcg-cbus_mask, BITMODE_CBUS);
+}
+
+static int ftdi_cbus_gpio_direction_output(struct gpio_chip *chip,
+ unsigned offset, int value)
+{
+ struct ftdi_cbus_gpio *fcg = to_ftdi_cbus_gpio(chip);
+
+ fcg-cbus_mask |= ((1 offset) 4);
+ if (value)
+ fcg-cbus_mask |= (1 offset);
+ else
+ fcg-cbus_mask = ~(1 offset);
+
+ return ftdi_sio_set_bitmode(fcg-port, fcg-cbus_mask, BITMODE_CBUS);
+}
+
+static void ftdi_cbus_gpio_set(struct gpio_chip *chip, unsigned offset,
+ int value)
+{
+ struct ftdi_cbus_gpio *fcg = to_ftdi_cbus_gpio(chip);
+ int ret;
+
+ if (value)
+ fcg-cbus_mask |= (1 offset);
+ else
+ fcg-cbus_mask = ~(1 offset);
+
+ ret = ftdi_sio_set_bitmode(fcg-port, fcg-cbus_mask, 0x20);
+ if (ret 0)
+ dev_warn(chip-dev, error setting pin value, %d\n, ret);
+}
+
+static int ftdi_cbus_gpio_get(struct gpio_chip *chip, unsigned offset)
+{
+ struct ftdi_cbus_gpio *fcg = to_ftdi_cbus_gpio(chip);
+ u8 val;
+ int ret;
+
+ ret = ftdi_sio_read_pins(fcg-port, val);
+
+ if (ret 0) {
+ dev_warn(chip-dev, error getting pin value, %d\n, ret);
+ return 0;
+ }
+
+ if (val (1 offset))
+ return 1;
+ else
+ return 0;
+}
+
+static struct gpio_chip ftdi_cbus_gpio_chip = {
+ .label = ftdi-cbus-gpio,
+
