drivers/tty/serial/8250/8250_men_mcb.c

   1 #include <linux/device.h>
   2 #include <linux/kernel.h>
   3 #include <linux/module.h>
   4 #include <linux/mcb.h>
   5 #include <linux/serial.h>
   6 #include <linux/serial_core.h>
   7 #include <linux/serial_8250.h>
   8 #include <uapi/linux/serial_core.h>
   9
  10 struct serial_8250_men_mcb_data {
  11         struct uart_8250_port uart;
  12         int line;
  13 };
  14
  15 /*
  16  * The Z125 16550-compatible UART has no fixed base clock assigned
  17  * So, depending on the board we're on, we need to adjust the
  18  * parameter in order to really set the correct baudrate, and
  19  * do so if possible without user interaction
  20  */
  21 static u32 men_z125_lookup_uartclk(struct mcb_device *mdev)
  22 {
  23         /* use default value if board is not available below */
  24         u32 clkval = 1041666;
  25
  26         dev_info(&mdev->dev, "%s on board %s\n",
  27                 dev_name(&mdev->dev),
  28                 mdev->bus->name);
  29         if  (strncmp(mdev->bus->name, "F075", 4) == 0)
  30                 clkval = 1041666;
  31         else if  (strncmp(mdev->bus->name, "F216", 4) == 0)
  32                 clkval = 1843200;
  33         else if (strncmp(mdev->bus->name, "G215", 4) == 0)
  34                 clkval = 1843200;
  35         else
  36                 dev_info(&mdev->dev,
  37                          "board not detected, using default uartclk\n");
  38
  39         clkval = clkval  << 4;
  40
  41         return clkval;
  42 }
  43
  44 static int serial_8250_men_mcb_probe(struct mcb_device *mdev,
  45                                      const struct mcb_device_id *id)
  46 {
  47         struct serial_8250_men_mcb_data *data;
  48         struct resource *mem;
  49
  50         data = devm_kzalloc(&mdev->dev,
  51                             sizeof(struct serial_8250_men_mcb_data),
  52                             GFP_KERNEL);
  53         if (!data)
  54                 return -ENOMEM;
  55
  56         mcb_set_drvdata(mdev, data);
  57         data->uart.port.dev = mdev->dma_dev;
  58         spin_lock_init(&data->uart.port.lock);
  59
  60         data->uart.port.type = PORT_16550;
  61         data->uart.port.flags = UPF_SKIP_TEST | UPF_SHARE_IRQ | UPF_FIXED_TYPE;
  62         data->uart.port.iotype = UPIO_MEM;
  63         data->uart.port.uartclk = men_z125_lookup_uartclk(mdev);
  64         data->uart.port.regshift = 0;
  65         data->uart.port.fifosize = 60;
  66
  67         mem = mcb_get_resource(mdev, IORESOURCE_MEM);
  68         if (mem == NULL)
  69                 return -ENXIO;
  70
  71         data->uart.port.irq = mcb_get_irq(mdev);
  72
  73         data->uart.port.membase = devm_ioremap_resource(&mdev->dev, mem);
  74         if (IS_ERR(data->uart.port.membase))
  75                 return PTR_ERR_OR_ZERO(data->uart.port.membase);
  76
  77         data->uart.port.mapbase = (unsigned long) mem->start;
  78         data->uart.port.iobase = data->uart.port.mapbase;
  79
  80         /* ok, register the port */
  81         data->line = serial8250_register_8250_port(&data->uart);
  82         if (data->line < 0)
  83                 return data->line;
  84
  85         dev_info(&mdev->dev, "found 16Z125 UART: ttyS%d\n", data->line);
  86
  87         return 0;
  88 }
  89
  90 static void serial_8250_men_mcb_remove(struct mcb_device *mdev)
  91 {
  92         struct serial_8250_men_mcb_data *data = mcb_get_drvdata(mdev);
  93
  94         if (data)
  95                 serial8250_unregister_port(data->line);
  96 }
  97
  98 static const struct mcb_device_id serial_8250_men_mcb_ids[] = {
  99         { .device = 0x7d },
 100         { }
 101 };
 102 MODULE_DEVICE_TABLE(mcb, serial_8250_men_mcb_ids);
 103
 104 static struct mcb_driver mcb_driver = {
 105         .driver = {
 106                 .name = "8250_men_mcb",
 107                 .owner = THIS_MODULE,
 108         },
 109         .probe = serial_8250_men_mcb_probe,
 110         .remove = serial_8250_men_mcb_remove,
 111         .id_table = serial_8250_men_mcb_ids,
 112 };
 113 module_mcb_driver(mcb_driver);
 114
 115 MODULE_LICENSE("GPL v2");
 116 MODULE_DESCRIPTION("MEN 16z125 8250 UART driver");
 117 MODULE_AUTHOR("Michael Moese <michael.moese@men.de");
 118 MODULE_ALIAS("mcb:16z125");