[PATCH V4 3/4] 8250: 8250_f81504: Add Fintek F81504/508/512 PCIE-to-UART/GPIO UART support
From: Peter Hung
Date: Tue Feb 23 2016 - 01:30:46 EST
This driver is 8250 driver for F81504/508/512, it'll handle the serial
port operation of this device. This module will depend on
MFD_FINTEK_F81504_CORE.
The serial ports support from 50bps to 1.5Mbps with Linux baudrate
define excluding 1.0Mbps due to not support 16MHz clock source.
PCI Configuration Space Registers, set:0~11(Max):
40h + 8 * set:
bit7~6: Clock source selector
00: 1.8432MHz
01: 18.432MHz
10: 24MHz
11: 14.769MHz
bit0: UART enable
41h + 8 * set:
bit5~4: RX trigger multiple
00: 1x * trigger level
01: 2x * trigger level
10: 4x * trigger level
11: 8x * trigger level
bit1~0: FIFO Size
11: 128Bytes
44h + 8 * set: UART IO address (LSB)
45h + 8 * set: UART IO address (MSB)
47h + 8 * set:
bit5: RTS invert (bit4 must enable)
bit4: RTS auto direction enable
0: RTS control by MCR
1: RTS driven high when TX, otherwise low
Suggested-by: One Thousand Gnomes <gnomes@xxxxxxxxxxxxxxxxxxx>
Suggested-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
Signed-off-by: Peter Hung <hpeter+linux_kernel@xxxxxxxxx>
---
drivers/tty/serial/8250/8250_f81504.c | 250 ++++++++++++++++++++++++++++++++++
drivers/tty/serial/8250/Kconfig | 10 ++
drivers/tty/serial/8250/Makefile | 1 +
3 files changed, 261 insertions(+)
create mode 100644 drivers/tty/serial/8250/8250_f81504.c
diff --git a/drivers/tty/serial/8250/8250_f81504.c b/drivers/tty/serial/8250/8250_f81504.c
new file mode 100644
index 0000000..2b6c3d3
--- /dev/null
+++ b/drivers/tty/serial/8250/8250_f81504.c
@@ -0,0 +1,250 @@
+#include <linux/pci.h>
+#include <linux/serial_8250.h>
+#include <linux/module.h>
+#include <linux/version.h>
+#include <linux/mfd/f81504.h>
+
+#include "8250.h"
+
+static u32 baudrate_table[] = { 1500000, 1152000, 921600 };
+static u8 clock_table[] = { F81504_CLKSEL_24_MHZ, F81504_CLKSEL_18_46_MHZ,
+ F81504_CLKSEL_14_77_MHZ };
+
+/* We should do proper H/W transceiver setting before change to RS485 mode */
+static int f81504_rs485_config(struct uart_port *port,
+ struct serial_rs485 *rs485)
+{
+ u8 setting;
+ u8 *index = port->private_data;
+ struct platform_device *pdev = container_of(port->dev,
+ struct platform_device, dev);
+ struct pci_dev *pci_dev = to_pci_dev(pdev->dev.parent);
+
+ pci_read_config_byte(pci_dev, F81504_UART_START_ADDR +
+ F81504_UART_OFFSET * *index + F81504_UART_MODE_OFFSET,
+ &setting);
+
+ if (!rs485)
+ rs485 = &port->rs485;
+ else if (rs485->flags & SER_RS485_ENABLED)
+ memset(rs485->padding, 0, sizeof(rs485->padding));
+ else
+ memset(rs485, 0, sizeof(*rs485));
+
+ /* F81504/508/512 not support RTS delay before or after send */
+ rs485->flags &= SER_RS485_ENABLED | SER_RS485_RTS_ON_SEND;
+
+ if (rs485->flags & SER_RS485_ENABLED) {
+ /* Enable RTS H/W control mode */
+ setting |= F81504_RTS_CONTROL_BY_HW;
+
+ if (rs485->flags & SER_RS485_RTS_ON_SEND) {
+ /* RTS driving high on TX */
+ setting &= ~F81504_RTS_INVERT;
+ } else {
+ /* RTS driving low on TX */
+ setting |= F81504_RTS_INVERT;
+ }
+
+ rs485->delay_rts_after_send = 0;
+ rs485->delay_rts_before_send = 0;
+ } else {
+ /* Disable RTS H/W control mode */
+ setting &= ~(F81504_RTS_CONTROL_BY_HW | F81504_RTS_INVERT);
+ }
+
+ pci_write_config_byte(pci_dev, F81504_UART_START_ADDR +
+ F81504_UART_OFFSET * *index + F81504_UART_MODE_OFFSET,
+ setting);
+
+ if (rs485 != &port->rs485)
+ port->rs485 = *rs485;
+
+ return 0;
+}
+
+static int f81504_check_baudrate(u32 baud, size_t *idx)
+{
+ size_t index;
+
+ for (index = 0; index < ARRAY_SIZE(baudrate_table); ++index) {
+ /* Clock source must larger than desire baud rate */
+ if (baud > baudrate_table[index])
+ continue;
+
+ /* Find divisible clock source */
+ if (!(baudrate_table[index] % baud)) {
+ if (idx)
+ *idx = index;
+ return 0;
+ }
+ }
+
+ return -EINVAL;
+}
+
+static void f81504_set_termios(struct uart_port *port,
+ struct ktermios *termios, struct ktermios *old)
+{
+ struct platform_device *pdev = container_of(port->dev,
+ struct platform_device, dev);
+ struct pci_dev *dev = to_pci_dev(pdev->dev.parent);
+ unsigned int baud = tty_termios_baud_rate(termios);
+ u8 tmp, *offset = port->private_data;
+ size_t i;
+
+ /* Not support for B1000000 due to haven't 16MHz clock source */
+ do {
+ /* Read current clock source (masked with CLOCK_RATE_MASK) */
+ pci_read_config_byte(dev, F81504_UART_START_ADDR + *offset *
+ F81504_UART_OFFSET, &tmp);
+
+ if (baud <= 115200) {
+ /*
+ * Direct use 1.8432MHz when baud rate smaller then or
+ * equal 115200bps.
+ */
+ port->uartclk = 115200 * 16;
+ pci_write_config_byte(dev, F81504_UART_START_ADDR +
+ *offset * F81504_UART_OFFSET,
+ tmp & ~F81504_CLOCK_RATE_MASK);
+ break;
+ }
+
+ if (!f81504_check_baudrate(baud, &i)) {
+ /* Had optimize value */
+ port->uartclk = baudrate_table[i] * 16;
+ tmp = (tmp & ~F81504_CLOCK_RATE_MASK) | clock_table[i];
+ pci_write_config_byte(dev, F81504_UART_START_ADDR +
+ *offset * F81504_UART_OFFSET, tmp);
+ break;
+ }
+
+ if (old && !f81504_check_baudrate(tty_termios_baud_rate(old),
+ NULL)) {
+ /*
+ * If it can't found suitable clock source but had old
+ * acceptable baud rate, we'll use it.
+ */
+ baud = tty_termios_baud_rate(old);
+ } else {
+ /*
+ * If it can't found suitable clock source and not old
+ * config, we'll direct set 115200bps for future use.
+ */
+ baud = 115200;
+ }
+
+ if (tty_termios_baud_rate(termios))
+ tty_termios_encode_baud_rate(termios, baud, baud);
+ } while (1);
+
+ serial8250_do_set_termios(port, termios, old);
+}
+
+static int f81504_register_port(struct platform_device *dev,
+ unsigned long address, int idx)
+{
+ struct pci_dev *pci_dev = to_pci_dev(dev->dev.parent);
+ struct uart_8250_port port;
+ u8 *data;
+
+ memset(&port, 0, sizeof(port));
+ data = devm_kzalloc(&dev->dev, sizeof(u8), GFP_KERNEL);
+ if (!data)
+ return -ENOMEM;
+
+ *data = idx;
+ port.port.iotype = UPIO_PORT;
+ port.port.irq = pci_dev->irq;
+ port.port.flags = UPF_SKIP_TEST | UPF_FIXED_TYPE | UPF_BOOT_AUTOCONF |
+ UPF_SHARE_IRQ;
+ port.port.uartclk = 1843200;
+ port.port.dev = &dev->dev;
+ port.port.iobase = address;
+ port.port.type = PORT_16550A;
+ port.port.fifosize = 128;
+ port.port.rs485_config = f81504_rs485_config;
+ port.port.set_termios = f81504_set_termios;
+ port.tx_loadsz = 32;
+ port.port.private_data = data; /* Save current idx */
+
+ return serial8250_register_8250_port(&port);
+}
+
+static int f81504_serial_probe(struct platform_device *pdev)
+{
+ int line;
+ size_t *index = (size_t *)dev_get_platdata(&pdev->dev);
+ struct resource *io = platform_get_resource(pdev, IORESOURCE_IO, 0);
+
+ line = f81504_register_port(pdev, io->start, *index);
+ if (line < 0)
+ return line;
+
+ /*
+ * Re-assign line to replace old port PCIE configuration space idx,
+ * port idx is saved in per-port private data.
+ */
+ *index = line;
+ return 0;
+}
+
+static int f81504_serial_remove(struct platform_device *pdev)
+{
+ size_t *line = (size_t *)dev_get_platdata(&pdev->dev);
+
+ serial8250_unregister_port(*line);
+ return 0;
+}
+
+
+#ifdef CONFIG_PM_SLEEP
+static int f81504_serial_suspend(struct device *dev)
+{
+ struct platform_device *pdev = to_platform_device(dev);
+ size_t *line = (size_t *)dev_get_platdata(&pdev->dev);
+
+ serial8250_suspend_port(*line);
+ return 0;
+}
+
+static int f81504_serial_resume(struct device *dev)
+{
+ struct platform_device *pdev = to_platform_device(dev);
+ size_t *line = (size_t *)dev_get_platdata(&pdev->dev);
+ struct uart_8250_port *port = serial8250_get_port(*line);
+
+ f81504_rs485_config(&port->port, NULL);
+ serial8250_resume_port(*line);
+ return 0;
+}
+#endif
+
+static SIMPLE_DEV_PM_OPS(f81504_serial_pm_ops, f81504_serial_suspend,
+ f81504_serial_resume);
+
+static struct platform_driver f81504_serial_driver = {
+ .driver = {
+ .name = F81504_SERIAL_NAME,
+ .pm = &f81504_serial_pm_ops,
+ },
+ .probe = f81504_serial_probe,
+ .remove = f81504_serial_remove,
+};
+
+static int __init f81504_serial_init(void)
+{
+ return platform_driver_register(&f81504_serial_driver);
+}
+subsys_initcall(f81504_serial_init);
+
+static void __exit f81504_serial_exit(void)
+{
+ platform_driver_unregister(&f81504_serial_driver);
+}
+module_exit(f81504_serial_exit);
+
+MODULE_AUTHOR("Peter Hong <Peter_Hong@xxxxxxxxxxxxx>");
+MODULE_DESCRIPTION("Fintek F81504/508/512 PCIE 16550A serial port driver");
+MODULE_LICENSE("GPL");
diff --git a/drivers/tty/serial/8250/Kconfig b/drivers/tty/serial/8250/Kconfig
index b03cb517..03586af 100644
--- a/drivers/tty/serial/8250/Kconfig
+++ b/drivers/tty/serial/8250/Kconfig
@@ -116,6 +116,16 @@ config SERIAL_8250_PCI
Note that serial ports on NetMos 9835 Multi-I/O cards are handled
by the parport_serial driver, enabled with CONFIG_PARPORT_SERIAL.
+config SERIAL_8250_F81504
+ tristate "Fintek F81504/508/512 16550 PCIE device support" if EXPERT
+ depends on SERIAL_8250 && MFD_FINTEK_F81504_CORE
+ default SERIAL_8250
+ help
+ This builds Fintek F81504/508/512 PCIE serial ports support.
+ You may be able to enable GPIO_F81504 to get GPIOLIB support if
+ the devices supported. Please enable MFD_FINTEK_F81504_CORE &
+ this with Y if you need a early console.
+
config SERIAL_8250_HP300
tristate
depends on SERIAL_8250 && HP300
diff --git a/drivers/tty/serial/8250/Makefile b/drivers/tty/serial/8250/Makefile
index b9b9bca..c84245e 100644
--- a/drivers/tty/serial/8250/Makefile
+++ b/drivers/tty/serial/8250/Makefile
@@ -9,6 +9,7 @@ obj-$(CONFIG_SERIAL_8250) += 8250.o 8250_base.o
8250_base-$(CONFIG_SERIAL_8250_DMA) += 8250_dma.o
obj-$(CONFIG_SERIAL_8250_GSC) += 8250_gsc.o
obj-$(CONFIG_SERIAL_8250_PCI) += 8250_pci.o
+obj-$(CONFIG_SERIAL_8250_F81504) += 8250_f81504.o
obj-$(CONFIG_SERIAL_8250_HP300) += 8250_hp300.o
obj-$(CONFIG_SERIAL_8250_CS) += serial_cs.o
obj-$(CONFIG_SERIAL_8250_ACORN) += 8250_acorn.o
--
1.9.1