diff options
Diffstat (limited to 'drivers/tty/serial/8250/8250_men_mcb.c')
| -rw-r--r-- | drivers/tty/serial/8250/8250_men_mcb.c | 176 |
1 files changed, 176 insertions, 0 deletions
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 000000000..f46ca13ff --- /dev/null +++ b/drivers/tty/serial/8250/8250_men_mcb.c @@ -0,0 +1,176 @@ +// SPDX-License-Identifier: GPL-2.0 +#include <linux/device.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/io.h> +#include <linux/mcb.h> +#include <linux/serial.h> +#include <linux/serial_core.h> +#include <linux/serial_8250.h> + +#define MEN_UART_ID_Z025 0x19 +#define MEN_UART_ID_Z057 0x39 +#define MEN_UART_ID_Z125 0x7d + +#define MEN_UART_MEM_SIZE 0x10 + +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_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 if (strncmp(mdev->bus->name, "F210", 4) == 0) + clkval = 115200; + else + dev_info(&mdev->dev, + "board not detected, using default uartclk\n"); + + clkval = clkval << 4; + + return clkval; +} + +static int get_num_ports(struct mcb_device *mdev, + void __iomem *membase) +{ + switch (mdev->id) { + case MEN_UART_ID_Z125: + return 1U; + case MEN_UART_ID_Z025: + return readb(membase) >> 4; + case MEN_UART_ID_Z057: + return 4U; + default: + dev_err(&mdev->dev, "no supported device!\n"); + return -ENODEV; + } +} + +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; + int num_ports; + int i; + void __iomem *membase; + + mem = mcb_get_resource(mdev, IORESOURCE_MEM); + if (mem == NULL) + return -ENXIO; + membase = devm_ioremap_resource(&mdev->dev, mem); + if (IS_ERR(membase)) + return PTR_ERR_OR_ZERO(membase); + + num_ports = get_num_ports(mdev, membase); + + dev_dbg(&mdev->dev, "found a 16z%03u with %u ports\n", + mdev->id, num_ports); + + if (num_ports <= 0 || num_ports > 4) { + dev_err(&mdev->dev, "unexpected number of ports: %u\n", + num_ports); + return -ENODEV; + } + + data = devm_kcalloc(&mdev->dev, num_ports, + sizeof(struct serial_8250_men_mcb_data), + GFP_KERNEL); + if (!data) + return -ENOMEM; + + mcb_set_drvdata(mdev, data); + + for (i = 0; i < num_ports; i++) { + data[i].uart.port.dev = mdev->dma_dev; + spin_lock_init(&data[i].uart.port.lock); + + data[i].uart.port.type = PORT_16550; + data[i].uart.port.flags = UPF_SKIP_TEST | UPF_SHARE_IRQ + | UPF_FIXED_TYPE; + data[i].uart.port.iotype = UPIO_MEM; + data[i].uart.port.uartclk = men_lookup_uartclk(mdev); + data[i].uart.port.regshift = 0; + data[i].uart.port.irq = mcb_get_irq(mdev); + data[i].uart.port.membase = membase; + data[i].uart.port.fifosize = 60; + data[i].uart.port.mapbase = (unsigned long) mem->start + + i * MEN_UART_MEM_SIZE; + data[i].uart.port.iobase = data[i].uart.port.mapbase; + + /* ok, register the port */ + data[i].line = serial8250_register_8250_port(&data[i].uart); + if (data[i].line < 0) { + dev_err(&mdev->dev, "unable to register UART port\n"); + return data[i].line; + } + dev_info(&mdev->dev, "found MCB UART: ttyS%d\n", data[i].line); + } + + return 0; +} + +static void serial_8250_men_mcb_remove(struct mcb_device *mdev) +{ + int num_ports, i; + struct serial_8250_men_mcb_data *data = mcb_get_drvdata(mdev); + + if (!data) + return; + + num_ports = get_num_ports(mdev, data[0].uart.port.membase); + if (num_ports <= 0 || num_ports > 4) { + dev_err(&mdev->dev, "error retrieving number of ports!\n"); + return; + } + + for (i = 0; i < num_ports; i++) + serial8250_unregister_port(data[i].line); +} + +static const struct mcb_device_id serial_8250_men_mcb_ids[] = { + { .device = MEN_UART_ID_Z025 }, + { .device = MEN_UART_ID_Z057 }, + { .device = MEN_UART_ID_Z125 }, + { } +}; +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 8250 UART driver"); +MODULE_AUTHOR("Michael Moese <michael.moese@men.de"); +MODULE_ALIAS("mcb:16z125"); +MODULE_ALIAS("mcb:16z025"); +MODULE_ALIAS("mcb:16z057"); +MODULE_IMPORT_NS(MCB); |