drivers/tty/serial/8250/8250_ingenic.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0+
 /*
  * Copyright (C) 2010 Lars-Peter Clausen <lars@metafoo.de>
  * Copyright (C) 2015 Imagination Technologies
  *
  * Ingenic SoC UART support
  */

 #include <linux/clk.h>
 #include <linux/console.h>
 #include <linux/io.h>
 #include <linux/libfdt.h>
 #include <linux/module.h>
 #include <linux/of.h>
 #include <linux/of_fdt.h>
 #include <linux/platform_device.h>
 #include <linux/serial_8250.h>
 #include <linux/serial_core.h>
 #include <linux/serial_reg.h>

 #include "8250.h"

 /** ingenic_uart_config: SOC specific config data. */
 struct ingenic_uart_config {
 	int tx_loadsz;
 	int fifosize;
 };

 struct ingenic_uart_data {
 	struct clk	*clk_module;
 	struct clk	*clk_baud;
 	int		line;
 };

 static const struct of_device_id of_match[];

 #define UART_FCR_UME	BIT(4)

 #define UART_MCR_MDCE	BIT(7)
 #define UART_MCR_FCM	BIT(6)

 static struct earlycon_device *early_device;

 static uint8_t early_in(struct uart_port *port, int offset)
 {
 	return readl(port->membase + (offset << 2));
 }

 static void early_out(struct uart_port *port, int offset, uint8_t value)
 {
 	writel(value, port->membase + (offset << 2));
 }

 static void ingenic_early_console_putc(struct uart_port *port, unsigned char c)
 {
 	u16 lsr;

 	do {
 		lsr = early_in(port, UART_LSR);
 	} while ((lsr & UART_LSR_TEMT) == 0);

 	early_out(port, UART_TX, c);
 }

 static void ingenic_early_console_write(struct console *console,
 					      const char *s, unsigned int count)
 {
 	uart_console_write(&early_device->port, s, count,
 			   ingenic_early_console_putc);
 }

 static void __init ingenic_early_console_setup_clock(struct earlycon_device *dev)
 {
 	void *fdt = initial_boot_params;
 	const __be32 *prop;
 	int offset;

 	offset = fdt_path_offset(fdt, "/ext");
 	if (offset < 0)
 		return;

 	prop = fdt_getprop(fdt, offset, "clock-frequency", NULL);
 	if (!prop)
 		return;

 	dev->port.uartclk = be32_to_cpup(prop);
 }

 static int __init ingenic_earlycon_setup_tail(struct earlycon_device *dev,
 					      const char *opt)
 {
 	struct uart_port *port = &dev->port;
 	unsigned int divisor;
 	int baud = 115200;

 	if (!dev->port.membase)
 		return -ENODEV;

 	if (opt) {
 		unsigned int parity, bits, flow; /* unused for now */

 		uart_parse_options(opt, &baud, &parity, &bits, &flow);
 	}

 	if (dev->baud)
 		baud = dev->baud;
 	divisor = DIV_ROUND_CLOSEST(port->uartclk, 16 * baud);

 	early_out(port, UART_IER, 0);
 	early_out(port, UART_LCR, UART_LCR_DLAB | UART_LCR_WLEN8);
 	early_out(port, UART_DLL, 0);
 	early_out(port, UART_DLM, 0);
 	early_out(port, UART_LCR, UART_LCR_WLEN8);
 	early_out(port, UART_FCR, UART_FCR_UME | UART_FCR_CLEAR_XMIT |
 			UART_FCR_CLEAR_RCVR | UART_FCR_ENABLE_FIFO);
 	early_out(port, UART_MCR, UART_MCR_RTS | UART_MCR_DTR);

 	early_out(port, UART_LCR, UART_LCR_DLAB | UART_LCR_WLEN8);
 	early_out(port, UART_DLL, divisor & 0xff);
 	early_out(port, UART_DLM, (divisor >> 8) & 0xff);
 	early_out(port, UART_LCR, UART_LCR_WLEN8);

 	early_device = dev;
 	dev->con->write = ingenic_early_console_write;

 	return 0;
 }

 static int __init ingenic_early_console_setup(struct earlycon_device *dev,
 					      const char *opt)
 {
 	ingenic_early_console_setup_clock(dev);

 	return ingenic_earlycon_setup_tail(dev, opt);
 }

 static int __init jz4750_early_console_setup(struct earlycon_device *dev,
 					     const char *opt)
 {
 	/*
 	 * JZ4750/55/60 have an optional /2 divider between the EXT
 	 * oscillator and some peripherals including UART, which will
 	 * be enabled if using a 24 MHz oscillator, and disabled when
 	 * using a 12 MHz oscillator.
 	 */
 	ingenic_early_console_setup_clock(dev);
 	if (dev->port.uartclk >= 16000000)
 		dev->port.uartclk /= 2;

 	return ingenic_earlycon_setup_tail(dev, opt);
 }

 OF_EARLYCON_DECLARE(jz4740_uart, "ingenic,jz4740-uart",
 		    ingenic_early_console_setup);

 OF_EARLYCON_DECLARE(jz4750_uart, "ingenic,jz4750-uart",
 		    jz4750_early_console_setup);

 OF_EARLYCON_DECLARE(jz4770_uart, "ingenic,jz4770-uart",
 		    ingenic_early_console_setup);

 OF_EARLYCON_DECLARE(jz4775_uart, "ingenic,jz4775-uart",
 		    ingenic_early_console_setup);

 OF_EARLYCON_DECLARE(jz4780_uart, "ingenic,jz4780-uart",
 		    ingenic_early_console_setup);

 OF_EARLYCON_DECLARE(x1000_uart, "ingenic,x1000-uart",
 		    ingenic_early_console_setup);

 static void ingenic_uart_serial_out(struct uart_port *p, int offset, int value)
 {
 	int ier;

 	switch (offset) {
 	case UART_FCR:
 		/* UART module enable */
 		value |= UART_FCR_UME;
 		break;

 	case UART_IER:
 		/*
 		 * Enable receive timeout interrupt with the receive line
 		 * status interrupt.
 		 */
 		value |= (value & 0x4) << 2;
 		break;

 	case UART_MCR:
 		/*
 		 * If we have enabled modem status IRQs we should enable
 		 * modem mode.
 		 */
 		ier = p->serial_in(p, UART_IER);

 		if (ier & UART_IER_MSI)
 			value |= UART_MCR_MDCE | UART_MCR_FCM;
 		else
 			value &= ~(UART_MCR_MDCE | UART_MCR_FCM);
 		break;

 	default:
 		break;
 	}

 	writeb(value, p->membase + (offset << p->regshift));
 }

 static unsigned int ingenic_uart_serial_in(struct uart_port *p, int offset)
 {
 	unsigned int value;

 	value = readb(p->membase + (offset << p->regshift));

 	/* Hide non-16550 compliant bits from higher levels */
 	switch (offset) {
 	case UART_FCR:
 		value &= ~UART_FCR_UME;
 		break;

 	case UART_MCR:
 		value &= ~(UART_MCR_MDCE | UART_MCR_FCM);
 		break;

 	default:
 		break;
 	}
 	return value;
 }

 static int ingenic_uart_probe(struct platform_device *pdev)
 {
 	struct uart_8250_port uart = {};
 	struct ingenic_uart_data *data;
 	const struct ingenic_uart_config *cdata;
 	struct resource *regs;
 	int irq, err, line;

 	cdata = of_device_get_match_data(&pdev->dev);
 	if (!cdata) {
 		dev_err(&pdev->dev, "Error: No device match found\n");
 		return -ENODEV;
 	}

 	irq = platform_get_irq(pdev, 0);
 	if (irq < 0)
 		return irq;

 	regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	if (!regs) {
 		dev_err(&pdev->dev, "no registers defined\n");
 		return -EINVAL;
 	}

 	data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
 	if (!data)
 		return -ENOMEM;

 	spin_lock_init(&uart.port.lock);
 	uart.port.type = PORT_16550A;
 	uart.port.flags = UPF_SKIP_TEST | UPF_IOREMAP | UPF_FIXED_TYPE;
 	uart.port.iotype = UPIO_MEM;
 	uart.port.mapbase = regs->start;
 	uart.port.regshift = 2;
 	uart.port.serial_out = ingenic_uart_serial_out;
 	uart.port.serial_in = ingenic_uart_serial_in;
 	uart.port.irq = irq;
 	uart.port.dev = &pdev->dev;
 	uart.port.fifosize = cdata->fifosize;
 	uart.tx_loadsz = cdata->tx_loadsz;
 	uart.capabilities = UART_CAP_FIFO | UART_CAP_RTOIE;

 	/* Check for a fixed line number */
 	line = of_alias_get_id(pdev->dev.of_node, "serial");
 	if (line >= 0)
 		uart.port.line = line;

 	uart.port.membase = devm_ioremap(&pdev->dev, regs->start,
 					 resource_size(regs));
 	if (!uart.port.membase)
 		return -ENOMEM;

 	data->clk_module = devm_clk_get(&pdev->dev, "module");
 	if (IS_ERR(data->clk_module))
 		return dev_err_probe(&pdev->dev, PTR_ERR(data->clk_module),
 				     "unable to get module clock\n");

 	data->clk_baud = devm_clk_get(&pdev->dev, "baud");
 	if (IS_ERR(data->clk_baud))
 		return dev_err_probe(&pdev->dev, PTR_ERR(data->clk_baud),
 				     "unable to get baud clock\n");

 	err = clk_prepare_enable(data->clk_module);
 	if (err) {
 		dev_err(&pdev->dev, "could not enable module clock: %d\n", err);
 		goto out;
 	}

 	err = clk_prepare_enable(data->clk_baud);
 	if (err) {
 		dev_err(&pdev->dev, "could not enable baud clock: %d\n", err);
 		goto out_disable_moduleclk;
 	}
 	uart.port.uartclk = clk_get_rate(data->clk_baud);

 	data->line = serial8250_register_8250_port(&uart);
 	if (data->line < 0) {
 		err = data->line;
 		goto out_disable_baudclk;
 	}

 	platform_set_drvdata(pdev, data);
 	return 0;

 out_disable_baudclk:
 	clk_disable_unprepare(data->clk_baud);
 out_disable_moduleclk:
 	clk_disable_unprepare(data->clk_module);
 out:
 	return err;
 }

 static int ingenic_uart_remove(struct platform_device *pdev)
 {
 	struct ingenic_uart_data *data = platform_get_drvdata(pdev);

 	serial8250_unregister_port(data->line);
 	clk_disable_unprepare(data->clk_module);
 	clk_disable_unprepare(data->clk_baud);
 	return 0;
 }

 static const struct ingenic_uart_config jz4740_uart_config = {
 	.tx_loadsz = 8,
 	.fifosize = 16,
 };

 static const struct ingenic_uart_config jz4760_uart_config = {
 	.tx_loadsz = 16,
 	.fifosize = 32,
 };

 static const struct ingenic_uart_config jz4780_uart_config = {
 	.tx_loadsz = 32,
 	.fifosize = 64,
 };

 static const struct ingenic_uart_config x1000_uart_config = {
 	.tx_loadsz = 32,
 	.fifosize = 64,
 };

 static const struct of_device_id of_match[] = {
 	{ .compatible = "ingenic,jz4740-uart", .data = &jz4740_uart_config },
 	{ .compatible = "ingenic,jz4750-uart", .data = &jz4760_uart_config },
 	{ .compatible = "ingenic,jz4760-uart", .data = &jz4760_uart_config },
 	{ .compatible = "ingenic,jz4770-uart", .data = &jz4760_uart_config },
 	{ .compatible = "ingenic,jz4775-uart", .data = &jz4760_uart_config },
 	{ .compatible = "ingenic,jz4780-uart", .data = &jz4780_uart_config },
 	{ .compatible = "ingenic,x1000-uart", .data = &x1000_uart_config },
 	{ /* sentinel */ }
 };
 MODULE_DEVICE_TABLE(of, of_match);

 static struct platform_driver ingenic_uart_platform_driver = {
 	.driver = {
 		.name		= "ingenic-uart",
 		.of_match_table	= of_match,
 	},
 	.probe			= ingenic_uart_probe,
 	.remove			= ingenic_uart_remove,
 };

 module_platform_driver(ingenic_uart_platform_driver);

 MODULE_AUTHOR("Paul Burton");
 MODULE_LICENSE("GPL");
 MODULE_DESCRIPTION("Ingenic SoC UART driver");
	// SPDX-License-Identifier: GPL-2.0+
	/*
	* Copyright (C) 2010 Lars-Peter Clausen <lars@metafoo.de>
	* Copyright (C) 2015 Imagination Technologies
	*
	* Ingenic SoC UART support
	*/

	#include <linux/clk.h>
	#include <linux/console.h>
	#include <linux/io.h>
	#include <linux/libfdt.h>
	#include <linux/module.h>
	#include <linux/of.h>
	#include <linux/of_fdt.h>
	#include <linux/platform_device.h>
	#include <linux/serial_8250.h>
	#include <linux/serial_core.h>
	#include <linux/serial_reg.h>

	#include "8250.h"

	/** ingenic_uart_config: SOC specific config data. */
	struct ingenic_uart_config {
	int tx_loadsz;
	int fifosize;
	};

	struct ingenic_uart_data {
	struct clk *clk_module;
	struct clk *clk_baud;
	int line;
	};

	static const struct of_device_id of_match[];

	#define UART_FCR_UME BIT(4)

	#define UART_MCR_MDCE BIT(7)
	#define UART_MCR_FCM BIT(6)

	static struct earlycon_device *early_device;

	static uint8_t early_in(struct uart_port *port, int offset)
	{
	return readl(port->membase + (offset << 2));
	}

	static void early_out(struct uart_port *port, int offset, uint8_t value)
	{
	writel(value, port->membase + (offset << 2));
	}

	static void ingenic_early_console_putc(struct uart_port *port, unsigned char c)
	{
	u16 lsr;

	do {
	lsr = early_in(port, UART_LSR);
	} while ((lsr & UART_LSR_TEMT) == 0);

	early_out(port, UART_TX, c);
	}

	static void ingenic_early_console_write(struct console *console,
	const char *s, unsigned int count)
	{
	uart_console_write(&early_device->port, s, count,
	ingenic_early_console_putc);
	}

	static void __init ingenic_early_console_setup_clock(struct earlycon_device *dev)
	{
	void *fdt = initial_boot_params;
	const __be32 *prop;
	int offset;

	offset = fdt_path_offset(fdt, "/ext");
	if (offset < 0)
	return;

	prop = fdt_getprop(fdt, offset, "clock-frequency", NULL);
	if (!prop)
	return;

	dev->port.uartclk = be32_to_cpup(prop);
	}

	static int __init ingenic_earlycon_setup_tail(struct earlycon_device *dev,
	const char *opt)
	{
	struct uart_port *port = &dev->port;
	unsigned int divisor;
	int baud = 115200;

	if (!dev->port.membase)
	return -ENODEV;

	if (opt) {
	unsigned int parity, bits, flow; /* unused for now */

	uart_parse_options(opt, &baud, &parity, &bits, &flow);
	}

	if (dev->baud)
	baud = dev->baud;
	divisor = DIV_ROUND_CLOSEST(port->uartclk, 16 * baud);

	early_out(port, UART_IER, 0);
	early_out(port, UART_LCR, UART_LCR_DLAB \| UART_LCR_WLEN8);
	early_out(port, UART_DLL, 0);
	early_out(port, UART_DLM, 0);
	early_out(port, UART_LCR, UART_LCR_WLEN8);
	early_out(port, UART_FCR, UART_FCR_UME \| UART_FCR_CLEAR_XMIT \|
	UART_FCR_CLEAR_RCVR \| UART_FCR_ENABLE_FIFO);
	early_out(port, UART_MCR, UART_MCR_RTS \| UART_MCR_DTR);

	early_out(port, UART_LCR, UART_LCR_DLAB \| UART_LCR_WLEN8);
	early_out(port, UART_DLL, divisor & 0xff);
	early_out(port, UART_DLM, (divisor >> 8) & 0xff);
	early_out(port, UART_LCR, UART_LCR_WLEN8);

	early_device = dev;
	dev->con->write = ingenic_early_console_write;

	return 0;
	}

	static int __init ingenic_early_console_setup(struct earlycon_device *dev,
	const char *opt)
	{
	ingenic_early_console_setup_clock(dev);

	return ingenic_earlycon_setup_tail(dev, opt);
	}

	static int __init jz4750_early_console_setup(struct earlycon_device *dev,
	const char *opt)
	{
	/*
	* JZ4750/55/60 have an optional /2 divider between the EXT
	* oscillator and some peripherals including UART, which will
	* be enabled if using a 24 MHz oscillator, and disabled when
	* using a 12 MHz oscillator.
	*/
	ingenic_early_console_setup_clock(dev);
	if (dev->port.uartclk >= 16000000)
	dev->port.uartclk /= 2;

	return ingenic_earlycon_setup_tail(dev, opt);
	}

	OF_EARLYCON_DECLARE(jz4740_uart, "ingenic,jz4740-uart",
	ingenic_early_console_setup);

	OF_EARLYCON_DECLARE(jz4750_uart, "ingenic,jz4750-uart",
	jz4750_early_console_setup);

	OF_EARLYCON_DECLARE(jz4770_uart, "ingenic,jz4770-uart",
	ingenic_early_console_setup);

	OF_EARLYCON_DECLARE(jz4775_uart, "ingenic,jz4775-uart",
	ingenic_early_console_setup);

	OF_EARLYCON_DECLARE(jz4780_uart, "ingenic,jz4780-uart",
	ingenic_early_console_setup);

	OF_EARLYCON_DECLARE(x1000_uart, "ingenic,x1000-uart",
	ingenic_early_console_setup);

	static void ingenic_uart_serial_out(struct uart_port *p, int offset, int value)
	{
	int ier;

	switch (offset) {
	case UART_FCR:
	/* UART module enable */
	value \|= UART_FCR_UME;
	break;

	case UART_IER:
	/*
	* Enable receive timeout interrupt with the receive line
	* status interrupt.
	*/
	value \|= (value & 0x4) << 2;
	break;

	case UART_MCR:
	/*
	* If we have enabled modem status IRQs we should enable
	* modem mode.
	*/
	ier = p->serial_in(p, UART_IER);

	if (ier & UART_IER_MSI)
	value \|= UART_MCR_MDCE \| UART_MCR_FCM;
	else
	value &= ~(UART_MCR_MDCE \| UART_MCR_FCM);
	break;

	default:
	break;
	}

	writeb(value, p->membase + (offset << p->regshift));
	}

	static unsigned int ingenic_uart_serial_in(struct uart_port *p, int offset)
	{
	unsigned int value;

	value = readb(p->membase + (offset << p->regshift));

	/* Hide non-16550 compliant bits from higher levels */
	switch (offset) {
	case UART_FCR:
	value &= ~UART_FCR_UME;
	break;

	case UART_MCR:
	value &= ~(UART_MCR_MDCE \| UART_MCR_FCM);
	break;

	default:
	break;
	}
	return value;
	}

	static int ingenic_uart_probe(struct platform_device *pdev)
	{
	struct uart_8250_port uart = {};
	struct ingenic_uart_data *data;
	const struct ingenic_uart_config *cdata;
	struct resource *regs;
	int irq, err, line;

	cdata = of_device_get_match_data(&pdev->dev);
	if (!cdata) {
	dev_err(&pdev->dev, "Error: No device match found\n");
	return -ENODEV;
	}

	irq = platform_get_irq(pdev, 0);
	if (irq < 0)
	return irq;

	regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	if (!regs) {
	dev_err(&pdev->dev, "no registers defined\n");
	return -EINVAL;
	}

	data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
	if (!data)
	return -ENOMEM;

	spin_lock_init(&uart.port.lock);
	uart.port.type = PORT_16550A;
	uart.port.flags = UPF_SKIP_TEST \| UPF_IOREMAP \| UPF_FIXED_TYPE;
	uart.port.iotype = UPIO_MEM;
	uart.port.mapbase = regs->start;
	uart.port.regshift = 2;
	uart.port.serial_out = ingenic_uart_serial_out;
	uart.port.serial_in = ingenic_uart_serial_in;
	uart.port.irq = irq;
	uart.port.dev = &pdev->dev;
	uart.port.fifosize = cdata->fifosize;
	uart.tx_loadsz = cdata->tx_loadsz;
	uart.capabilities = UART_CAP_FIFO \| UART_CAP_RTOIE;

	/* Check for a fixed line number */
	line = of_alias_get_id(pdev->dev.of_node, "serial");
	if (line >= 0)
	uart.port.line = line;

	uart.port.membase = devm_ioremap(&pdev->dev, regs->start,
	resource_size(regs));
	if (!uart.port.membase)
	return -ENOMEM;

	data->clk_module = devm_clk_get(&pdev->dev, "module");
	if (IS_ERR(data->clk_module))
	return dev_err_probe(&pdev->dev, PTR_ERR(data->clk_module),
	"unable to get module clock\n");

	data->clk_baud = devm_clk_get(&pdev->dev, "baud");
	if (IS_ERR(data->clk_baud))
	return dev_err_probe(&pdev->dev, PTR_ERR(data->clk_baud),
	"unable to get baud clock\n");

	err = clk_prepare_enable(data->clk_module);
	if (err) {
	dev_err(&pdev->dev, "could not enable module clock: %d\n", err);
	goto out;
	}

	err = clk_prepare_enable(data->clk_baud);
	if (err) {
	dev_err(&pdev->dev, "could not enable baud clock: %d\n", err);
	goto out_disable_moduleclk;
	}
	uart.port.uartclk = clk_get_rate(data->clk_baud);

	data->line = serial8250_register_8250_port(&uart);
	if (data->line < 0) {
	err = data->line;
	goto out_disable_baudclk;
	}

	platform_set_drvdata(pdev, data);
	return 0;

	out_disable_baudclk:
	clk_disable_unprepare(data->clk_baud);
	out_disable_moduleclk:
	clk_disable_unprepare(data->clk_module);
	out:
	return err;
	}

	static int ingenic_uart_remove(struct platform_device *pdev)
	{
	struct ingenic_uart_data *data = platform_get_drvdata(pdev);

	serial8250_unregister_port(data->line);
	clk_disable_unprepare(data->clk_module);
	clk_disable_unprepare(data->clk_baud);
	return 0;
	}

	static const struct ingenic_uart_config jz4740_uart_config = {
	.tx_loadsz = 8,
	.fifosize = 16,
	};

	static const struct ingenic_uart_config jz4760_uart_config = {
	.tx_loadsz = 16,
	.fifosize = 32,
	};

	static const struct ingenic_uart_config jz4780_uart_config = {
	.tx_loadsz = 32,
	.fifosize = 64,
	};

	static const struct ingenic_uart_config x1000_uart_config = {
	.tx_loadsz = 32,
	.fifosize = 64,
	};

	static const struct of_device_id of_match[] = {
	{ .compatible = "ingenic,jz4740-uart", .data = &jz4740_uart_config },
	{ .compatible = "ingenic,jz4750-uart", .data = &jz4760_uart_config },
	{ .compatible = "ingenic,jz4760-uart", .data = &jz4760_uart_config },
	{ .compatible = "ingenic,jz4770-uart", .data = &jz4760_uart_config },
	{ .compatible = "ingenic,jz4775-uart", .data = &jz4760_uart_config },
	{ .compatible = "ingenic,jz4780-uart", .data = &jz4780_uart_config },
	{ .compatible = "ingenic,x1000-uart", .data = &x1000_uart_config },
	{ /* sentinel */ }
	};
	MODULE_DEVICE_TABLE(of, of_match);

	static struct platform_driver ingenic_uart_platform_driver = {
	.driver = {
	.name = "ingenic-uart",
	.of_match_table = of_match,
	},
	.probe = ingenic_uart_probe,
	.remove = ingenic_uart_remove,
	};

	module_platform_driver(ingenic_uart_platform_driver);

	MODULE_AUTHOR("Paul Burton");
	MODULE_LICENSE("GPL");
	MODULE_DESCRIPTION("Ingenic SoC UART driver");