8250_men_mcb.c (4584B)
1// SPDX-License-Identifier: GPL-2.0 2#include <linux/device.h> 3#include <linux/kernel.h> 4#include <linux/module.h> 5#include <linux/io.h> 6#include <linux/mcb.h> 7#include <linux/serial.h> 8#include <linux/serial_core.h> 9#include <linux/serial_8250.h> 10#include <uapi/linux/serial_core.h> 11 12#define MEN_UART_ID_Z025 0x19 13#define MEN_UART_ID_Z057 0x39 14#define MEN_UART_ID_Z125 0x7d 15 16#define MEN_UART_MEM_SIZE 0x10 17 18struct serial_8250_men_mcb_data { 19 struct uart_8250_port uart; 20 int line; 21}; 22 23/* 24 * The Z125 16550-compatible UART has no fixed base clock assigned 25 * So, depending on the board we're on, we need to adjust the 26 * parameter in order to really set the correct baudrate, and 27 * do so if possible without user interaction 28 */ 29static u32 men_lookup_uartclk(struct mcb_device *mdev) 30{ 31 /* use default value if board is not available below */ 32 u32 clkval = 1041666; 33 34 dev_info(&mdev->dev, "%s on board %s\n", 35 dev_name(&mdev->dev), 36 mdev->bus->name); 37 if (strncmp(mdev->bus->name, "F075", 4) == 0) 38 clkval = 1041666; 39 else if (strncmp(mdev->bus->name, "F216", 4) == 0) 40 clkval = 1843200; 41 else if (strncmp(mdev->bus->name, "G215", 4) == 0) 42 clkval = 1843200; 43 else if (strncmp(mdev->bus->name, "F210", 4) == 0) 44 clkval = 115200; 45 else 46 dev_info(&mdev->dev, 47 "board not detected, using default uartclk\n"); 48 49 clkval = clkval << 4; 50 51 return clkval; 52} 53 54static int get_num_ports(struct mcb_device *mdev, 55 void __iomem *membase) 56{ 57 switch (mdev->id) { 58 case MEN_UART_ID_Z125: 59 return 1U; 60 case MEN_UART_ID_Z025: 61 return readb(membase) >> 4; 62 case MEN_UART_ID_Z057: 63 return 4U; 64 default: 65 dev_err(&mdev->dev, "no supported device!\n"); 66 return -ENODEV; 67 } 68} 69 70static int serial_8250_men_mcb_probe(struct mcb_device *mdev, 71 const struct mcb_device_id *id) 72{ 73 struct serial_8250_men_mcb_data *data; 74 struct resource *mem; 75 int num_ports; 76 int i; 77 void __iomem *membase; 78 79 mem = mcb_get_resource(mdev, IORESOURCE_MEM); 80 if (mem == NULL) 81 return -ENXIO; 82 membase = devm_ioremap_resource(&mdev->dev, mem); 83 if (IS_ERR(membase)) 84 return PTR_ERR_OR_ZERO(membase); 85 86 num_ports = get_num_ports(mdev, membase); 87 88 dev_dbg(&mdev->dev, "found a 16z%03u with %u ports\n", 89 mdev->id, num_ports); 90 91 if (num_ports <= 0 || num_ports > 4) { 92 dev_err(&mdev->dev, "unexpected number of ports: %u\n", 93 num_ports); 94 return -ENODEV; 95 } 96 97 data = devm_kcalloc(&mdev->dev, num_ports, 98 sizeof(struct serial_8250_men_mcb_data), 99 GFP_KERNEL); 100 if (!data) 101 return -ENOMEM; 102 103 mcb_set_drvdata(mdev, data); 104 105 for (i = 0; i < num_ports; i++) { 106 data[i].uart.port.dev = mdev->dma_dev; 107 spin_lock_init(&data[i].uart.port.lock); 108 109 data[i].uart.port.type = PORT_16550; 110 data[i].uart.port.flags = UPF_SKIP_TEST | UPF_SHARE_IRQ 111 | UPF_FIXED_TYPE; 112 data[i].uart.port.iotype = UPIO_MEM; 113 data[i].uart.port.uartclk = men_lookup_uartclk(mdev); 114 data[i].uart.port.regshift = 0; 115 data[i].uart.port.irq = mcb_get_irq(mdev); 116 data[i].uart.port.membase = membase; 117 data[i].uart.port.fifosize = 60; 118 data[i].uart.port.mapbase = (unsigned long) mem->start 119 + i * MEN_UART_MEM_SIZE; 120 data[i].uart.port.iobase = data[i].uart.port.mapbase; 121 122 /* ok, register the port */ 123 data[i].line = serial8250_register_8250_port(&data[i].uart); 124 if (data[i].line < 0) { 125 dev_err(&mdev->dev, "unable to register UART port\n"); 126 return data[i].line; 127 } 128 dev_info(&mdev->dev, "found MCB UART: ttyS%d\n", data[i].line); 129 } 130 131 return 0; 132} 133 134static void serial_8250_men_mcb_remove(struct mcb_device *mdev) 135{ 136 int num_ports, i; 137 struct serial_8250_men_mcb_data *data = mcb_get_drvdata(mdev); 138 139 if (!data) 140 return; 141 142 num_ports = get_num_ports(mdev, data[0].uart.port.membase); 143 if (num_ports <= 0 || num_ports > 4) { 144 dev_err(&mdev->dev, "error retrieving number of ports!\n"); 145 return; 146 } 147 148 for (i = 0; i < num_ports; i++) 149 serial8250_unregister_port(data[i].line); 150} 151 152static const struct mcb_device_id serial_8250_men_mcb_ids[] = { 153 { .device = MEN_UART_ID_Z025 }, 154 { .device = MEN_UART_ID_Z057 }, 155 { .device = MEN_UART_ID_Z125 }, 156 { } 157}; 158MODULE_DEVICE_TABLE(mcb, serial_8250_men_mcb_ids); 159 160static struct mcb_driver mcb_driver = { 161 .driver = { 162 .name = "8250_men_mcb", 163 .owner = THIS_MODULE, 164 }, 165 .probe = serial_8250_men_mcb_probe, 166 .remove = serial_8250_men_mcb_remove, 167 .id_table = serial_8250_men_mcb_ids, 168}; 169module_mcb_driver(mcb_driver); 170 171MODULE_LICENSE("GPL v2"); 172MODULE_DESCRIPTION("MEN 8250 UART driver"); 173MODULE_AUTHOR("Michael Moese <michael.moese@men.de"); 174MODULE_ALIAS("mcb:16z125"); 175MODULE_ALIAS("mcb:16z025"); 176MODULE_ALIAS("mcb:16z057"); 177MODULE_IMPORT_NS(MCB);