diff options
| -rw-r--r-- | drivers/tty/serial/8250/8250_exar.c | 129 |
1 files changed, 128 insertions, 1 deletions
diff --git a/drivers/tty/serial/8250/8250_exar.c b/drivers/tty/serial/8250/8250_exar.c index 9931e26ca061..b105f4cb51aa 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 { @@ -236,18 +274,107 @@ 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("linux,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; |