xref: /linux/drivers/tty/serial/8250/8250_men_mcb.c (revision a8b70ccf10e38775785d9cb12ead916474549f99)
1 #include <linux/device.h>
2 #include <linux/kernel.h>
3 #include <linux/module.h>
4 #include <linux/io.h>
5 #include <linux/mcb.h>
6 #include <linux/serial.h>
7 #include <linux/serial_core.h>
8 #include <linux/serial_8250.h>
9 #include <uapi/linux/serial_core.h>
10 
11 #define MEN_UART_ID_Z025 0x19
12 #define MEN_UART_ID_Z057 0x39
13 #define MEN_UART_ID_Z125 0x7d
14 
15 #define MEN_UART_MEM_SIZE 0x10
16 
17 struct serial_8250_men_mcb_data {
18 	struct uart_8250_port uart;
19 	int line;
20 };
21 
22 /*
23  * The Z125 16550-compatible UART has no fixed base clock assigned
24  * So, depending on the board we're on, we need to adjust the
25  * parameter in order to really set the correct baudrate, and
26  * do so if possible without user interaction
27  */
28 static u32 men_lookup_uartclk(struct mcb_device *mdev)
29 {
30 	/* use default value if board is not available below */
31 	u32 clkval = 1041666;
32 
33 	dev_info(&mdev->dev, "%s on board %s\n",
34 		dev_name(&mdev->dev),
35 		mdev->bus->name);
36 	if  (strncmp(mdev->bus->name, "F075", 4) == 0)
37 		clkval = 1041666;
38 	else if (strncmp(mdev->bus->name, "F216", 4) == 0)
39 		clkval = 1843200;
40 	else if (strncmp(mdev->bus->name, "G215", 4) == 0)
41 		clkval = 1843200;
42 	else if (strncmp(mdev->bus->name, "F210", 4) == 0)
43 		clkval = 115200;
44 	else
45 		dev_info(&mdev->dev,
46 			 "board not detected, using default uartclk\n");
47 
48 	clkval = clkval  << 4;
49 
50 	return clkval;
51 }
52 
53 static unsigned int get_num_ports(struct mcb_device *mdev,
54 				  void __iomem *membase)
55 {
56 	switch (mdev->id) {
57 	case MEN_UART_ID_Z125:
58 		return 1U;
59 	case MEN_UART_ID_Z025:
60 		return readb(membase) >> 4;
61 	case MEN_UART_ID_Z057:
62 		return 4U;
63 	default:
64 		dev_err(&mdev->dev, "no supported device!\n");
65 		return -ENODEV;
66 	}
67 }
68 
69 static int serial_8250_men_mcb_probe(struct mcb_device *mdev,
70 				     const struct mcb_device_id *id)
71 {
72 	struct serial_8250_men_mcb_data *data;
73 	struct resource *mem;
74 	unsigned int num_ports;
75 	unsigned int i;
76 	void __iomem *membase;
77 
78 	mem = mcb_get_resource(mdev, IORESOURCE_MEM);
79 	if (mem == NULL)
80 		return -ENXIO;
81 	membase = devm_ioremap_resource(&mdev->dev, mem);
82 	if (IS_ERR(membase))
83 		return PTR_ERR_OR_ZERO(membase);
84 
85 	num_ports = get_num_ports(mdev, membase);
86 
87 	dev_dbg(&mdev->dev, "found a 16z%03u with %u ports\n",
88 		mdev->id, num_ports);
89 
90 	if (num_ports == 0 || num_ports > 4) {
91 		dev_err(&mdev->dev, "unexpected number of ports: %u\n",
92 			num_ports);
93 		return -ENODEV;
94 	}
95 
96 	data = devm_kcalloc(&mdev->dev, num_ports,
97 			    sizeof(struct serial_8250_men_mcb_data),
98 			    GFP_KERNEL);
99 	if (!data)
100 		return -ENOMEM;
101 
102 	mcb_set_drvdata(mdev, data);
103 
104 	for (i = 0; i < num_ports; i++) {
105 		data[i].uart.port.dev = mdev->dma_dev;
106 		spin_lock_init(&data[i].uart.port.lock);
107 
108 		data[i].uart.port.type = PORT_16550;
109 		data[i].uart.port.flags = UPF_SKIP_TEST | UPF_SHARE_IRQ
110 					  | UPF_FIXED_TYPE;
111 		data[i].uart.port.iotype = UPIO_MEM;
112 		data[i].uart.port.uartclk = men_lookup_uartclk(mdev);
113 		data[i].uart.port.regshift = 0;
114 		data[i].uart.port.irq = mcb_get_irq(mdev);
115 		data[i].uart.port.membase = membase;
116 		data[i].uart.port.fifosize = 60;
117 		data[i].uart.port.mapbase = (unsigned long) mem->start
118 					    + i * MEN_UART_MEM_SIZE;
119 		data[i].uart.port.iobase = data[i].uart.port.mapbase;
120 
121 		/* ok, register the port */
122 		data[i].line = serial8250_register_8250_port(&data[i].uart);
123 		if (data[i].line < 0) {
124 			dev_err(&mdev->dev, "unable to register UART port\n");
125 			return data[i].line;
126 		}
127 		dev_info(&mdev->dev, "found MCB UART: ttyS%d\n", data[i].line);
128 	}
129 
130 	return 0;
131 }
132 
133 static void serial_8250_men_mcb_remove(struct mcb_device *mdev)
134 {
135 	unsigned int num_ports, i;
136 	struct serial_8250_men_mcb_data *data = mcb_get_drvdata(mdev);
137 
138 	if (!data)
139 		return;
140 
141 	num_ports = get_num_ports(mdev, data[0].uart.port.membase);
142 	if (num_ports < 0 || num_ports > 4) {
143 		dev_err(&mdev->dev, "error retrieving number of ports!\n");
144 		return;
145 	}
146 
147 	for (i = 0; i < num_ports; i++)
148 		serial8250_unregister_port(data[i].line);
149 }
150 
151 static const struct mcb_device_id serial_8250_men_mcb_ids[] = {
152 	{ .device = MEN_UART_ID_Z025 },
153 	{ .device = MEN_UART_ID_Z057 },
154 	{ .device = MEN_UART_ID_Z125 },
155 	{ }
156 };
157 MODULE_DEVICE_TABLE(mcb, serial_8250_men_mcb_ids);
158 
159 static struct mcb_driver mcb_driver = {
160 	.driver = {
161 		.name = "8250_men_mcb",
162 		.owner = THIS_MODULE,
163 	},
164 	.probe = serial_8250_men_mcb_probe,
165 	.remove = serial_8250_men_mcb_remove,
166 	.id_table = serial_8250_men_mcb_ids,
167 };
168 module_mcb_driver(mcb_driver);
169 
170 MODULE_LICENSE("GPL v2");
171 MODULE_DESCRIPTION("MEN 8250 UART driver");
172 MODULE_AUTHOR("Michael Moese <michael.moese@men.de");
173 MODULE_ALIAS("mcb:16z125");
174 MODULE_ALIAS("mcb:16z025");
175 MODULE_ALIAS("mcb:16z057");
176