[linux-2.6-block.git] / drivers / tty / serial / 8250 / 8250_em.c

/*
 * Renesas Emma Mobile 8250 driver
 *
 *  Copyright (C) 2012 Magnus Damm
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

#include <linux/device.h>
#include <linux/io.h>
#include <linux/module.h>
#include <linux/serial_8250.h>
#include <linux/serial_core.h>
#include <linux/serial_reg.h>
#include <linux/platform_device.h>
#include <linux/clk.h>
#include <linux/slab.h>

#include "8250.h"

#define UART_DLL_EM 9
#define UART_DLM_EM 10

struct serial8250_em_priv {
	struct clk *sclk;
	int line;
};

static void serial8250_em_serial_out(struct uart_port *p, int offset, int value)
{
	switch (offset) {
	case UART_TX: /* TX @ 0x00 */
		writeb(value, p->membase);
		break;
	case UART_FCR: /* FCR @ 0x0c (+1) */
	case UART_LCR: /* LCR @ 0x10 (+1) */
	case UART_MCR: /* MCR @ 0x14 (+1) */
	case UART_SCR: /* SCR @ 0x20 (+1) */
		writel(value, p->membase + ((offset + 1) << 2));
		break;
	case UART_IER: /* IER @ 0x04 */
		value &= 0x0f; /* only 4 valid bits - not Xscale */
		/* fall-through */
	case UART_DLL_EM: /* DLL @ 0x24 (+9) */
	case UART_DLM_EM: /* DLM @ 0x28 (+9) */
		writel(value, p->membase + (offset << 2));
	}
}

static unsigned int serial8250_em_serial_in(struct uart_port *p, int offset)
{
	switch (offset) {
	case UART_RX: /* RX @ 0x00 */
		return readb(p->membase);
	case UART_MCR: /* MCR @ 0x14 (+1) */
	case UART_LSR: /* LSR @ 0x18 (+1) */
	case UART_MSR: /* MSR @ 0x1c (+1) */
	case UART_SCR: /* SCR @ 0x20 (+1) */
		return readl(p->membase + ((offset + 1) << 2));
	case UART_IER: /* IER @ 0x04 */
	case UART_IIR: /* IIR @ 0x08 */
	case UART_DLL_EM: /* DLL @ 0x24 (+9) */
	case UART_DLM_EM: /* DLM @ 0x28 (+9) */
		return readl(p->membase + (offset << 2));
	}
	return 0;
}

static int serial8250_em_serial_dl_read(struct uart_8250_port *up)
{
	return serial_in(up, UART_DLL_EM) | serial_in(up, UART_DLM_EM) << 8;
}

static void serial8250_em_serial_dl_write(struct uart_8250_port *up, int value)
{
	serial_out(up, UART_DLL_EM, value & 0xff);
	serial_out(up, UART_DLM_EM, value >> 8 & 0xff);
}

static int serial8250_em_probe(struct platform_device *pdev)
{
	struct resource *regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	struct resource *irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
	struct serial8250_em_priv *priv;
	struct uart_8250_port up;
	int ret;

	if (!regs || !irq) {
		dev_err(&pdev->dev, "missing registers or irq\n");
		return -EINVAL;
	}

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

	priv->sclk = devm_clk_get(&pdev->dev, "sclk");
	if (IS_ERR(priv->sclk)) {
		dev_err(&pdev->dev, "unable to get clock\n");
		return PTR_ERR(priv->sclk);
	}

	memset(&up, 0, sizeof(up));
	up.port.mapbase = regs->start;
	up.port.irq = irq->start;
	up.port.type = PORT_UNKNOWN;
	up.port.flags = UPF_BOOT_AUTOCONF | UPF_FIXED_PORT | UPF_IOREMAP;
	up.port.dev = &pdev->dev;
	up.port.private_data = priv;

	clk_prepare_enable(priv->sclk);
	up.port.uartclk = clk_get_rate(priv->sclk);

	up.port.iotype = UPIO_MEM32;
	up.port.serial_in = serial8250_em_serial_in;
	up.port.serial_out = serial8250_em_serial_out;
	up.dl_read = serial8250_em_serial_dl_read;
	up.dl_write = serial8250_em_serial_dl_write;

	ret = serial8250_register_8250_port(&up);
	if (ret < 0) {
		dev_err(&pdev->dev, "unable to register 8250 port\n");
		clk_disable_unprepare(priv->sclk);
		return ret;
	}

	priv->line = ret;
	platform_set_drvdata(pdev, priv);
	return 0;
}

static int serial8250_em_remove(struct platform_device *pdev)
{
	struct serial8250_em_priv *priv = platform_get_drvdata(pdev);

	serial8250_unregister_port(priv->line);
	clk_disable_unprepare(priv->sclk);
	return 0;
}

static const struct of_device_id serial8250_em_dt_ids[] = {
	{ .compatible = "renesas,em-uart", },
	{},
};
MODULE_DEVICE_TABLE(of, serial8250_em_dt_ids);

static struct platform_driver serial8250_em_platform_driver = {
	.driver = {
		.name		= "serial8250-em",
		.of_match_table = serial8250_em_dt_ids,
		.owner		= THIS_MODULE,
	},
	.probe			= serial8250_em_probe,
	.remove			= serial8250_em_remove,
};

module_platform_driver(serial8250_em_platform_driver);

MODULE_AUTHOR("Magnus Damm");
MODULE_DESCRIPTION("Renesas Emma Mobile 8250 Driver");
MODULE_LICENSE("GPL v2");
Commit	Line	Data
22886ee9 MD	1	/*
	2	* Renesas Emma Mobile 8250 driver
	3	*
	4	* Copyright (C) 2012 Magnus Damm
	5	*
	6	* This program is free software; you can redistribute it and/or modify
	7	* it under the terms of the GNU General Public License as published by
	8	* the Free Software Foundation; either version 2 of the License
	9	*
	10	* This program is distributed in the hope that it will be useful,
	11	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	12	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	13	* GNU General Public License for more details.
	14	*
	15	* You should have received a copy of the GNU General Public License
	16	* along with this program; if not, write to the Free Software
	17	* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
	18	*/
	19
	20	#include <linux/device.h>
22886ee9 MD	21	#include <linux/io.h>
	22	#include <linux/module.h>
	23	#include <linux/serial_8250.h>
	24	#include <linux/serial_core.h>
	25	#include <linux/serial_reg.h>
	26	#include <linux/platform_device.h>
	27	#include <linux/clk.h>
	28	#include <linux/slab.h>
	29
	30	#include "8250.h"
	31
	32	#define UART_DLL_EM 9
	33	#define UART_DLM_EM 10
	34
	35	struct serial8250_em_priv {
	36	struct clk *sclk;
	37	int line;
	38	};
	39
	40	static void serial8250_em_serial_out(struct uart_port *p, int offset, int value)
	41	{
	42	switch (offset) {
	43	case UART_TX: /* TX @ 0x00 */
	44	writeb(value, p->membase);
	45	break;
	46	case UART_FCR: /* FCR @ 0x0c (+1) */
	47	case UART_LCR: /* LCR @ 0x10 (+1) */
	48	case UART_MCR: /* MCR @ 0x14 (+1) */
	49	case UART_SCR: /* SCR @ 0x20 (+1) */
	50	writel(value, p->membase + ((offset + 1) << 2));
	51	break;
	52	case UART_IER: /* IER @ 0x04 */
	53	value &= 0x0f; /* only 4 valid bits - not Xscale */
	54	/* fall-through */
	55	case UART_DLL_EM: /* DLL @ 0x24 (+9) */
	56	case UART_DLM_EM: /* DLM @ 0x28 (+9) */
	57	writel(value, p->membase + (offset << 2));
	58	}
	59	}
	60
	61	static unsigned int serial8250_em_serial_in(struct uart_port *p, int offset)
	62	{
	63	switch (offset) {
	64	case UART_RX: /* RX @ 0x00 */
	65	return readb(p->membase);
	66	case UART_MCR: /* MCR @ 0x14 (+1) */
	67	case UART_LSR: /* LSR @ 0x18 (+1) */
	68	case UART_MSR: /* MSR @ 0x1c (+1) */
	69	case UART_SCR: /* SCR @ 0x20 (+1) */
	70	return readl(p->membase + ((offset + 1) << 2));
	71	case UART_IER: /* IER @ 0x04 */
	72	case UART_IIR: /* IIR @ 0x08 */
	73	case UART_DLL_EM: /* DLL @ 0x24 (+9) */
	74	case UART_DLM_EM: /* DLM @ 0x28 (+9) */
	75	return readl(p->membase + (offset << 2));
	76	}
	77	return 0;
	78	}
	79
	80	static int serial8250_em_serial_dl_read(struct uart_8250_port *up)
	81	{
	82	return serial_in(up, UART_DLL_EM) \| serial_in(up, UART_DLM_EM) << 8;
	83	}
	84
85	static void serial8250_em_serial_dl_write(struct uart_8250_port *up, int value)
86	{
87	serial_out(up, UART_DLL_EM, value & 0xff);
88	serial_out(up, UART_DLM_EM, value >> 8 & 0xff);
89	}
90
9671f099	91	static int serial8250_em_probe(struct platform_device *pdev)
22886ee9 MD	92	{
	93	struct resource *regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	94	struct resource *irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
	95	struct serial8250_em_priv *priv;
	96	struct uart_8250_port up;
299a6257	97	int ret;
22886ee9 MD	98
	99	if (!regs \|\| !irq) {
	100	dev_err(&pdev->dev, "missing registers or irq\n");
299a6257	101	return -EINVAL;
22886ee9 MD	102	}
22886ee9 MD	103
299a6257	104	priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
86b20dfe	105	if (!priv)
299a6257	106	return -ENOMEM;
22886ee9	107
299a6257	108	priv->sclk = devm_clk_get(&pdev->dev, "sclk");
94e792ab	109	if (IS_ERR(priv->sclk)) {
22886ee9	110	dev_err(&pdev->dev, "unable to get clock\n");
299a6257	111	return PTR_ERR(priv->sclk);
22886ee9 MD	112	}
	113
	114	memset(&up, 0, sizeof(up));
	115	up.port.mapbase = regs->start;
	116	up.port.irq = irq->start;
	117	up.port.type = PORT_UNKNOWN;
	118	up.port.flags = UPF_BOOT_AUTOCONF \| UPF_FIXED_PORT \| UPF_IOREMAP;
	119	up.port.dev = &pdev->dev;
	120	up.port.private_data = priv;
	121
12082ba2	122	clk_prepare_enable(priv->sclk);
22886ee9 MD	123	up.port.uartclk = clk_get_rate(priv->sclk);
	124
	125	up.port.iotype = UPIO_MEM32;
	126	up.port.serial_in = serial8250_em_serial_in;
	127	up.port.serial_out = serial8250_em_serial_out;
	128	up.dl_read = serial8250_em_serial_dl_read;
	129	up.dl_write = serial8250_em_serial_dl_write;
	130
	131	ret = serial8250_register_8250_port(&up);
	132	if (ret < 0) {
	133	dev_err(&pdev->dev, "unable to register 8250 port\n");
12082ba2	134	clk_disable_unprepare(priv->sclk);
299a6257	135	return ret;
22886ee9 MD	136	}
	137
	138	priv->line = ret;
	139	platform_set_drvdata(pdev, priv);
	140	return 0;
22886ee9 MD	141	}
22886ee9 MD	142
ae8d8a14	143	static int serial8250_em_remove(struct platform_device *pdev)
22886ee9 MD	144	{
	145	struct serial8250_em_priv *priv = platform_get_drvdata(pdev);
	146
	147	serial8250_unregister_port(priv->line);
12082ba2	148	clk_disable_unprepare(priv->sclk);
22886ee9 MD	149	return 0;
	150	}
	151
512f82a0	152	static const struct of_device_id serial8250_em_dt_ids[] = {
3e62c413 MD	153	{ .compatible = "renesas,em-uart", },
	154	{},
	155	};
	156	MODULE_DEVICE_TABLE(of, serial8250_em_dt_ids);
	157
22886ee9 MD	158	static struct platform_driver serial8250_em_platform_driver = {
	159	.driver = {
	160	.name = "serial8250-em",
3e62c413	161	.of_match_table = serial8250_em_dt_ids,
22886ee9 MD	162	.owner = THIS_MODULE,
	163	},
	164	.probe = serial8250_em_probe,
2d47b716	165	.remove = serial8250_em_remove,
22886ee9 MD	166	};
	167
	168	module_platform_driver(serial8250_em_platform_driver);
	169
	170	MODULE_AUTHOR("Magnus Damm");
	171	MODULE_DESCRIPTION("Renesas Emma Mobile 8250 Driver");
	172	MODULE_LICENSE("GPL v2");