From 562e6ef81f9b3dadeb7d05a6055e502d43caa830 Mon Sep 17 00:00:00 2001 From: Michael Moese Date: Wed, 2 Aug 2017 09:58:53 +0200 Subject: [PATCH] Introduce 8250_men_mcb This patch introduces the 8250_men_mcb driver for the MEN 16Z125 IP-Core. This is a 16550-type UART with a 60 byte FIFO. Due to strange old hardware, every board using this IP core requires different values for uartclk. A reasonable default is included in addition to the support of three boards. Additional values for other boards will be added later. This v2 has some whitespace fixes, I screwed this up yesterday. Signed-off-by: Michael Moese Reviewed-by: Johannes Thumshirn Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serial/8250/8250_men_mcb.c | 118 +++++++++++++++++++++++++ drivers/tty/serial/8250/Kconfig | 11 +++ drivers/tty/serial/8250/Makefile | 1 + 3 files changed, 130 insertions(+) create mode 100644 drivers/tty/serial/8250/8250_men_mcb.c diff --git a/drivers/tty/serial/8250/8250_men_mcb.c b/drivers/tty/serial/8250/8250_men_mcb.c new file mode 100644 index 000000000000..308977807994 --- /dev/null +++ b/drivers/tty/serial/8250/8250_men_mcb.c @@ -0,0 +1,118 @@ +#include +#include +#include +#include +#include +#include +#include +#include + +struct serial_8250_men_mcb_data { + struct uart_8250_port uart; + int line; +}; + +/* + * The Z125 16550-compatible UART has no fixed base clock assigned + * So, depending on the board we're on, we need to adjust the + * parameter in order to really set the correct baudrate, and + * do so if possible without user interaction + */ +static u32 men_z125_lookup_uartclk(struct mcb_device *mdev) +{ + /* use default value if board is not available below */ + u32 clkval = 1041666; + + dev_info(&mdev->dev, "%s on board %s\n", + dev_name(&mdev->dev), + mdev->bus->name); + if (strncmp(mdev->bus->name, "F075", 4) == 0) + clkval = 1041666; + else if (strncmp(mdev->bus->name, "F216", 4) == 0) + clkval = 1843200; + else if (strncmp(mdev->bus->name, "G215", 4) == 0) + clkval = 1843200; + else + dev_info(&mdev->dev, + "board not detected, using default uartclk\n"); + + clkval = clkval << 4; + + return clkval; +} + +static int serial_8250_men_mcb_probe(struct mcb_device *mdev, + const struct mcb_device_id *id) +{ + struct serial_8250_men_mcb_data *data; + struct resource *mem; + + data = devm_kzalloc(&mdev->dev, + sizeof(struct serial_8250_men_mcb_data), + GFP_KERNEL); + if (!data) + return -ENOMEM; + + mcb_set_drvdata(mdev, data); + data->uart.port.dev = mdev->dma_dev; + spin_lock_init(&data->uart.port.lock); + + data->uart.port.type = PORT_16550; + data->uart.port.flags = UPF_SKIP_TEST | UPF_SHARE_IRQ | UPF_FIXED_TYPE; + data->uart.port.iotype = UPIO_MEM; + data->uart.port.uartclk = men_z125_lookup_uartclk(mdev); + data->uart.port.regshift = 0; + data->uart.port.fifosize = 60; + + mem = mcb_get_resource(mdev, IORESOURCE_MEM); + if (mem == NULL) + return -ENXIO; + + data->uart.port.irq = mcb_get_irq(mdev); + + data->uart.port.membase = devm_ioremap_resource(&mdev->dev, mem); + if (IS_ERR(data->uart.port.membase)) + return PTR_ERR_OR_ZERO(data->uart.port.membase); + + data->uart.port.mapbase = (unsigned long) mem->start; + data->uart.port.iobase = data->uart.port.mapbase; + + /* ok, register the port */ + data->line = serial8250_register_8250_port(&data->uart); + if (data->line < 0) + return data->line; + + dev_info(&mdev->dev, "found 16Z125 UART: ttyS%d\n", data->line); + + return 0; +} + +static void serial_8250_men_mcb_remove(struct mcb_device *mdev) +{ + struct serial_8250_men_mcb_data *data = mcb_get_drvdata(mdev); + + if (data) + serial8250_unregister_port(data->line); +} + +static const struct mcb_device_id serial_8250_men_mcb_ids[] = { + { .device = 0x7d }, + { } +}; +MODULE_DEVICE_TABLE(mcb, serial_8250_men_mcb_ids); + +static struct mcb_driver mcb_driver = { + .driver = { + .name = "8250_men_mcb", + .owner = THIS_MODULE, + }, + .probe = serial_8250_men_mcb_probe, + .remove = serial_8250_men_mcb_remove, + .id_table = serial_8250_men_mcb_ids, +}; +module_mcb_driver(mcb_driver); + +MODULE_LICENSE("GPL v2"); +MODULE_DESCRIPTION("MEN 16z125 8250 UART driver"); +MODULE_AUTHOR("Michael Moese