2 * Copyright (C) 2010 Lars-Peter Clausen <lars@metafoo.de>
3 * Copyright (C) 2015 Imagination Technologies
5 * Ingenic SoC UART support
7 * This program is free software; you can redistribute it and/or modify it
8 * under the terms of the GNU General Public License as published by the
9 * Free Software Foundation; either version 2 of the License, or (at your
10 * option) any later version.
12 * You should have received a copy of the GNU General Public License along
13 * with this program; if not, write to the Free Software Foundation, Inc.,
14 * 675 Mass Ave, Cambridge, MA 02139, USA.
17 #include <linux/clk.h>
18 #include <linux/console.h>
20 #include <linux/libfdt.h>
21 #include <linux/module.h>
23 #include <linux/of_fdt.h>
24 #include <linux/of_device.h>
25 #include <linux/platform_device.h>
26 #include <linux/serial_8250.h>
27 #include <linux/serial_core.h>
28 #include <linux/serial_reg.h>
32 /** ingenic_uart_config: SOC specific config data. */
33 struct ingenic_uart_config {
38 struct ingenic_uart_data {
39 struct clk *clk_module;
44 static const struct of_device_id of_match[];
46 #define UART_FCR_UME BIT(4)
48 #define UART_MCR_MDCE BIT(7)
49 #define UART_MCR_FCM BIT(6)
51 #ifdef CONFIG_SERIAL_EARLYCON
52 static struct earlycon_device *early_device;
54 static uint8_t __init early_in(struct uart_port *port, int offset)
56 return readl(port->membase + (offset << 2));
59 static void __init early_out(struct uart_port *port, int offset, uint8_t value)
61 writel(value, port->membase + (offset << 2));
64 static void __init ingenic_early_console_putc(struct uart_port *port, int c)
69 lsr = early_in(port, UART_LSR);
70 } while ((lsr & UART_LSR_TEMT) == 0);
72 early_out(port, UART_TX, c);
75 static void __init ingenic_early_console_write(struct console *console,
76 const char *s, unsigned int count)
78 uart_console_write(&early_device->port, s, count,
79 ingenic_early_console_putc);
82 static void __init ingenic_early_console_setup_clock(struct earlycon_device *dev)
84 void *fdt = initial_boot_params;
88 offset = fdt_path_offset(fdt, "/ext");
92 prop = fdt_getprop(fdt, offset, "clock-frequency", NULL);
96 dev->port.uartclk = be32_to_cpup(prop);
99 static int __init ingenic_early_console_setup(struct earlycon_device *dev,
102 struct uart_port *port = &dev->port;
103 unsigned int baud, divisor;
105 if (!dev->port.membase)
108 ingenic_early_console_setup_clock(dev);
110 baud = dev->baud ?: 115200;
111 divisor = DIV_ROUND_CLOSEST(port->uartclk, 16 * baud);
113 early_out(port, UART_IER, 0);
114 early_out(port, UART_LCR, UART_LCR_DLAB | UART_LCR_WLEN8);
115 early_out(port, UART_DLL, 0);
116 early_out(port, UART_DLM, 0);
117 early_out(port, UART_LCR, UART_LCR_WLEN8);
118 early_out(port, UART_FCR, UART_FCR_UME | UART_FCR_CLEAR_XMIT |
119 UART_FCR_CLEAR_RCVR | UART_FCR_ENABLE_FIFO);
120 early_out(port, UART_MCR, UART_MCR_RTS | UART_MCR_DTR);
122 early_out(port, UART_LCR, UART_LCR_DLAB | UART_LCR_WLEN8);
123 early_out(port, UART_DLL, divisor & 0xff);
124 early_out(port, UART_DLM, (divisor >> 8) & 0xff);
125 early_out(port, UART_LCR, UART_LCR_WLEN8);
128 dev->con->write = ingenic_early_console_write;
133 EARLYCON_DECLARE(jz4740_uart, ingenic_early_console_setup);
134 OF_EARLYCON_DECLARE(jz4740_uart, "ingenic,jz4740-uart",
135 ingenic_early_console_setup);
137 EARLYCON_DECLARE(jz4775_uart, ingenic_early_console_setup);
138 OF_EARLYCON_DECLARE(jz4775_uart, "ingenic,jz4775-uart",
139 ingenic_early_console_setup);
141 EARLYCON_DECLARE(jz4780_uart, ingenic_early_console_setup);
142 OF_EARLYCON_DECLARE(jz4780_uart, "ingenic,jz4780-uart",
143 ingenic_early_console_setup);
144 #endif /* CONFIG_SERIAL_EARLYCON */
146 static void ingenic_uart_serial_out(struct uart_port *p, int offset, int value)
152 /* UART module enable */
153 value |= UART_FCR_UME;
157 /* Enable receive timeout interrupt with the
158 * receive line status interrupt */
159 value |= (value & 0x4) << 2;
163 /* If we have enabled modem status IRQs we should enable modem
165 ier = p->serial_in(p, UART_IER);
167 if (ier & UART_IER_MSI)
168 value |= UART_MCR_MDCE | UART_MCR_FCM;
170 value &= ~(UART_MCR_MDCE | UART_MCR_FCM);
177 writeb(value, p->membase + (offset << p->regshift));
180 static unsigned int ingenic_uart_serial_in(struct uart_port *p, int offset)
184 value = readb(p->membase + (offset << p->regshift));
186 /* Hide non-16550 compliant bits from higher levels */
189 value &= ~UART_FCR_UME;
193 value &= ~(UART_MCR_MDCE | UART_MCR_FCM);
202 static int ingenic_uart_probe(struct platform_device *pdev)
204 struct uart_8250_port uart = {};
205 struct resource *regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
206 struct resource *irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
207 struct ingenic_uart_data *data;
208 const struct ingenic_uart_config *cdata;
209 const struct of_device_id *match;
212 match = of_match_device(of_match, &pdev->dev);
214 dev_err(&pdev->dev, "Error: No device match found\n");
220 dev_err(&pdev->dev, "no registers/irq defined\n");
224 data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
228 spin_lock_init(&uart.port.lock);
229 uart.port.type = PORT_16550A;
230 uart.port.flags = UPF_SKIP_TEST | UPF_IOREMAP | UPF_FIXED_TYPE;
231 uart.port.iotype = UPIO_MEM;
232 uart.port.mapbase = regs->start;
233 uart.port.regshift = 2;
234 uart.port.serial_out = ingenic_uart_serial_out;
235 uart.port.serial_in = ingenic_uart_serial_in;
236 uart.port.irq = irq->start;
237 uart.port.dev = &pdev->dev;
238 uart.port.fifosize = cdata->fifosize;
239 uart.tx_loadsz = cdata->tx_loadsz;
240 uart.capabilities = UART_CAP_FIFO | UART_CAP_RTOIE;
242 /* Check for a fixed line number */
243 line = of_alias_get_id(pdev->dev.of_node, "serial");
245 uart.port.line = line;
247 uart.port.membase = devm_ioremap(&pdev->dev, regs->start,
248 resource_size(regs));
249 if (!uart.port.membase)
252 data->clk_module = devm_clk_get(&pdev->dev, "module");
253 if (IS_ERR(data->clk_module)) {
254 err = PTR_ERR(data->clk_module);
255 if (err != -EPROBE_DEFER)
257 "unable to get module clock: %d\n", err);
261 data->clk_baud = devm_clk_get(&pdev->dev, "baud");
262 if (IS_ERR(data->clk_baud)) {
263 err = PTR_ERR(data->clk_baud);
264 if (err != -EPROBE_DEFER)
266 "unable to get baud clock: %d\n", err);
270 err = clk_prepare_enable(data->clk_module);
272 dev_err(&pdev->dev, "could not enable module clock: %d\n", err);
276 err = clk_prepare_enable(data->clk_baud);
278 dev_err(&pdev->dev, "could not enable baud clock: %d\n", err);
279 goto out_disable_moduleclk;
281 uart.port.uartclk = clk_get_rate(data->clk_baud);
283 data->line = serial8250_register_8250_port(&uart);
284 if (data->line < 0) {
286 goto out_disable_baudclk;
289 platform_set_drvdata(pdev, data);
293 clk_disable_unprepare(data->clk_baud);
294 out_disable_moduleclk:
295 clk_disable_unprepare(data->clk_module);
300 static int ingenic_uart_remove(struct platform_device *pdev)
302 struct ingenic_uart_data *data = platform_get_drvdata(pdev);
304 serial8250_unregister_port(data->line);
305 clk_disable_unprepare(data->clk_module);
306 clk_disable_unprepare(data->clk_baud);
310 static const struct ingenic_uart_config jz4740_uart_config = {
315 static const struct ingenic_uart_config jz4760_uart_config = {
320 static const struct ingenic_uart_config jz4780_uart_config = {
325 static const struct of_device_id of_match[] = {
326 { .compatible = "ingenic,jz4740-uart", .data = &jz4740_uart_config },
327 { .compatible = "ingenic,jz4760-uart", .data = &jz4760_uart_config },
328 { .compatible = "ingenic,jz4775-uart", .data = &jz4760_uart_config },
329 { .compatible = "ingenic,jz4780-uart", .data = &jz4780_uart_config },
332 MODULE_DEVICE_TABLE(of, of_match);
334 static struct platform_driver ingenic_uart_platform_driver = {
336 .name = "ingenic-uart",
337 .of_match_table = of_match,
339 .probe = ingenic_uart_probe,
340 .remove = ingenic_uart_remove,
343 module_platform_driver(ingenic_uart_platform_driver);
345 MODULE_AUTHOR("Paul Burton");
346 MODULE_LICENSE("GPL");
347 MODULE_DESCRIPTION("Ingenic SoC UART driver");