This patch lets you set the RS485 cappabilites of the device through
TIOCSRS485 and TIOCGRS485 as defined on Documentation/serial/serial-rs485.txt
In order to probe the device, the PNP id and the device id is used.
There is only one device per system, therefore a static mutex is used to
avoid race conditions due to the indirect addressing.
Signed-off-by: Ricardo Ribalda Delgado <ricardo.ribalda@xxxxxxxxx>
---
drivers/tty/serial/8250/8250_fintek.c | 231 ++++++++++++++++++++++++++++++++++
drivers/tty/serial/8250/Kconfig | 9 ++
drivers/tty/serial/8250/Makefile | 1 +
3 files changed, 241 insertions(+)
create mode 100644 drivers/tty/serial/8250/8250_fintek.c
diff --git a/drivers/tty/serial/8250/8250_fintek.c b/drivers/tty/serial/8250/8250_fintek.c
new file mode 100644
index 0000000..97e7349
--- /dev/null
+++ b/drivers/tty/serial/8250/8250_fintek.c
@@ -0,0 +1,231 @@
+/*
+ * Probe for F81216A LPC to 4 UART
+ *
+ * Based on drivers/tty/serial/8250_pnp.c, by Russell King, et al
+ *
+ * Copyright (C) 2014 Ricardo Ribalda, Qtechnology A/S
+ *
+ *
+ * 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.
+ */
+#include <linux/module.h>
+#include <linux/pci.h>
+#include <linux/pnp.h>
+#include <linux/kernel.h>
+#include <linux/serial_core.h>
+#include "8250.h"
+
+#define ADDR_PORT 0x4E
+#define DATA_PORT 0x4F
+#define ENTRY_KEY 0x77
+#define CHIP_ID1 0x20
+#define CHIP_ID1_VAL 0x02
+#define CHIP_ID2 0x21
+#define CHIP_ID2_VAL 0x16
+#define VENDOR_ID1 0x23
+#define VENDOR_ID1_VAL 0x19
+#define VENDOR_ID2 0x24
+#define VENDOR_ID2_VAL 0x34
+#define LDN 0x7
+
+#define RS485 0xF0
+#define RTS_INVERT BIT(5)
+#define RS485_URA BIT(4)
+#define RXW4C_IRA BIT(3)
+#define TXW4C_IRA BIT(3)
+
+static DEFINE_MUTEX(fintek_mutex);
+
+static int fintek_8250_get_index(resource_size_t base_addr)
+{
+ resource_size_t base[] = {0x3f8, 0x2f8, 0x3e8, 0x2e8};
+ int i;
+
+ for (i = 0; i < ARRAY_SIZE(base); i++)
+ if (base_addr == base[i])
+ return i;
+
+ return -ENODEV;
+}
+
+static int fintek_8250_check_id(void)
+{
+
+ outb(CHIP_ID1, ADDR_PORT);
+ if (inb(DATA_PORT) != CHIP_ID1_VAL)
+ return -ENODEV;
+
+ outb(CHIP_ID2, ADDR_PORT);
+ if (inb(DATA_PORT) != CHIP_ID2_VAL)
+ return -ENODEV;
+
+ outb(VENDOR_ID1, ADDR_PORT);
+ if (inb(DATA_PORT) != VENDOR_ID1_VAL)
+ return -ENODEV;
+
+ outb(VENDOR_ID2, ADDR_PORT);
+ if (inb(DATA_PORT) != VENDOR_ID2_VAL)
+ return -ENODEV;
+
+ return 0;
+}
+
+int fintek_8250_rs4850_config(struct uart_8250_port *uart,
+ struct serial_rs485 *rs485)
+{
+ uint8_t config = 0;
+ int index = fintek_8250_get_index(uart->port.iobase);
+
+ if (index < 0)
+ return -EINVAL;
+
+ if (!rs485->flags & SER_RS485_ENABLED)
+ memset(rs485, 0, sizeof(*rs485));
+ else
+ memset(rs485->padding, 0, sizeof(rs485->padding));
+
+ rs485->flags &= SER_RS485_ENABLED | SER_RS485_RTS_ON_SEND |
+ SER_RS485_RTS_AFTER_SEND;
+
+ if (rs485->delay_rts_before_send) {
+ rs485->delay_rts_before_send = 1;
+ config |= TXW4C_IRA;
+ }
+
+ if (rs485->delay_rts_after_send) {
+ rs485->delay_rts_after_send = 1;
+ config |= RXW4C_IRA;
+ }
+
+ if ((!!(rs485->flags & SER_RS485_RTS_ON_SEND)) ==
+ (!!(rs485->flags & SER_RS485_RTS_AFTER_SEND)))
+ rs485->flags &= SER_RS485_ENABLED;
+ else
+ config |= RS485_URA;
+
+ if (rs485->flags & SER_RS485_RTS_ON_SEND)
+ config |= RTS_INVERT;
+
+ mutex_lock(&fintek_mutex);
+ outb(LDN, ADDR_PORT);
+ outb(index, DATA_PORT);
+ outb(RS485, ADDR_PORT);
+ outb(config, DATA_PORT);
+ mutex_unlock(&fintek_mutex);
+
+ return 0;
+}
+
+static int
+fintek_8250_probe(struct pnp_dev *dev, const struct pnp_device_id *dev_id)
+{
+ int line;
+ struct uart_8250_port uart;
+ int ret;
+
+ if (!pnp_port_valid(dev, 0))
+ return -ENODEV;
+
+ if (fintek_8250_get_index(pnp_port_start(dev, 0)) < 0)
+ return -ENODEV;
+
+ /* Enable configuration registers*/
+ mutex_lock(&fintek_mutex);
+ outb(ENTRY_KEY, ADDR_PORT);
+ outb(ENTRY_KEY, ADDR_PORT);
+
+ /*Check ID*/
+ ret = fintek_8250_check_id();
+ mutex_unlock(&fintek_mutex);
+ if (ret)
+ return ret;
+
+ memset(&uart, 0, sizeof(uart));
+ if (!pnp_irq_valid(dev, 0))
+ return -ENODEV;
+ uart.port.irq = pnp_irq(dev, 0);
+ uart.port.iobase = pnp_port_start(dev, 0);
+ uart.port.iotype = UPIO_PORT;
+ uart.rs485_config = fintek_8250_rs4850_config;
+
+ uart.port.flags |= UPF_SKIP_TEST | UPF_BOOT_AUTOCONF;
+ if (pnp_irq_flags(dev, 0) & IORESOURCE_IRQ_SHAREABLE)
+ uart.port.flags |= UPF_SHARE_IRQ;
+ uart.port.uartclk = 1843200;
+ uart.port.dev = &dev->dev;
+
+ line = serial8250_register_8250_port(&uart);
+ if (line < 0)
+ return -ENODEV;
+
+ pnp_set_drvdata(dev, (void *)((long)line + 1));
+ return 0;
+}
+
+static void fintek_8250_remove(struct pnp_dev *dev)
+{
+ long line = (long)pnp_get_drvdata(dev);
+
+ if (line)
+ serial8250_unregister_port(line - 1);
+}
+
+#ifdef CONFIG_PM
+static int fintek_8250_suspend(struct pnp_dev *dev, pm_message_t state)
+{
+ long line = (long)pnp_get_drvdata(dev);
+
+ if (!line)
+ return -ENODEV;
+ serial8250_suspend_port(line - 1);
+ return 0;
+}
+
+static int fintek_8250_resume(struct pnp_dev *dev)
+{
+ long line = (long)pnp_get_drvdata(dev);
+
+ if (!line)
+ return -ENODEV;
+ serial8250_resume_port(line - 1);
+ return 0;
+}
+#else
+#define fintek_8250_suspend NULL
+#define fintek_8250_resume NULL
+#endif /* CONFIG_PM */
+
+static const struct pnp_device_id fintek_dev_table[] = {
+ /* Qtechnology Panel PC / IO1000 */
+ { "PNP0501"},
+ {}
+};
+
+MODULE_DEVICE_TABLE(pnp, fintek_dev_table);
+
+static struct pnp_driver fintek_8250_driver = {
+ .name = "8250_fintek",
+ .probe = fintek_8250_probe,
+ .remove = fintek_8250_remove,
+ .suspend = fintek_8250_suspend,
+ .resume = fintek_8250_resume,
+ .id_table = fintek_dev_table,
+};
+
+int fintek_8250_init(void)
+{
+ return pnp_register_driver(&fintek_8250_driver);
+}
+module_init(fintek_8250_init);
+
+void fintek_8250_exit(void)
+{
+ pnp_unregister_driver(&fintek_8250_driver);
+}
+module_exit(fintek_8250_exit);
+
+MODULE_DESCRIPTION("Fintek F812164 module");
+MODULE_AUTHOR("Ricardo Ribalda <ricardo.ribalda@xxxxxxxxx>");
+MODULE_LICENSE("GPL");
diff --git a/drivers/tty/serial/8250/Kconfig b/drivers/tty/serial/8250/Kconfig
index 349ee59..8b5c40a 100644
--- a/drivers/tty/serial/8250/Kconfig
+++ b/drivers/tty/serial/8250/Kconfig
@@ -298,3 +298,12 @@ config SERIAL_8250_RT288X
If you have a Ralink RT288x/RT305x SoC based board and want to use the
serial port, say Y to this option. The driver can handle up to 2 serial
ports. If unsure, say N.
+
+config SERIAL_8250_FINTEK
+ tristate "Support for Fintek F81216A LPC to 4 UART"
+ depends on SERIAL_8250 && PNP
+ help
+ Selecting this option will add support for the Fintek F81216A
+ LPC to 4 UART. This device has some RS485 functionality not available
+ through the PNP driver. If unsure, say N.
+
diff --git a/drivers/tty/serial/8250/Makefile b/drivers/tty/serial/8250/Makefile
index 36d68d0..e08407d 100644
--- a/drivers/tty/serial/8250/Makefile
+++ b/drivers/tty/serial/8250/Makefile
@@ -20,3 +20,4 @@ obj-$(CONFIG_SERIAL_8250_HUB6) += 8250_hub6.o
obj-$(CONFIG_SERIAL_8250_FSL) += 8250_fsl.o
obj-$(CONFIG_SERIAL_8250_DW) += 8250_dw.o
obj-$(CONFIG_SERIAL_8250_EM) += 8250_em.o
+obj-$(CONFIG_SERIAL_8250_FINTEK) += 8250_fintek.o
--
2.0.1
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