[deliverable/linux.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/init.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) {
		dev_err(&pdev->dev, "unable to allocate private data\n");
		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>
	21	#include <linux/init.h>
	22	#include <linux/io.h>
	23	#include <linux/module.h>
	24	#include <linux/serial_8250.h>
	25	#include <linux/serial_core.h>
	26	#include <linux/serial_reg.h>
	27	#include <linux/platform_device.h>
	28	#include <linux/clk.h>
	29	#include <linux/slab.h>
	30
	31	#include "8250.h"
	32
	33	#define UART_DLL_EM 9
	34	#define UART_DLM_EM 10
	35
	36	struct serial8250_em_priv {
	37	struct clk *sclk;
	38	int line;
	39	};
	40
	41	static void serial8250_em_serial_out(struct uart_port *p, int offset, int value)
	42	{
	43	switch (offset) {
	44	case UART_TX: /* TX @ 0x00 */
	45	writeb(value, p->membase);
	46	break;
	47	case UART_FCR: /* FCR @ 0x0c (+1) */
	48	case UART_LCR: /* LCR @ 0x10 (+1) */
	49	case UART_MCR: /* MCR @ 0x14 (+1) */
	50	case UART_SCR: /* SCR @ 0x20 (+1) */
	51	writel(value, p->membase + ((offset + 1) << 2));
	52	break;
	53	case UART_IER: /* IER @ 0x04 */
	54	value &= 0x0f; /* only 4 valid bits - not Xscale */
	55	/* fall-through */
	56	case UART_DLL_EM: /* DLL @ 0x24 (+9) */
	57	case UART_DLM_EM: /* DLM @ 0x28 (+9) */
	58	writel(value, p->membase + (offset << 2));
	59	}
	60	}
	61
	62	static unsigned int serial8250_em_serial_in(struct uart_port *p, int offset)
	63	{
	64	switch (offset) {
65	case UART_RX: /* RX @ 0x00 */
66	return readb(p->membase);
67	case UART_MCR: /* MCR @ 0x14 (+1) */
68	case UART_LSR: /* LSR @ 0x18 (+1) */
69	case UART_MSR: /* MSR @ 0x1c (+1) */
70	case UART_SCR: /* SCR @ 0x20 (+1) */
71	return readl(p->membase + ((offset + 1) << 2));
72	case UART_IER: /* IER @ 0x04 */
73	case UART_IIR: /* IIR @ 0x08 */
74	case UART_DLL_EM: /* DLL @ 0x24 (+9) */
75	case UART_DLM_EM: /* DLM @ 0x28 (+9) */
76	return readl(p->membase + (offset << 2));
77	}
78	return 0;
79	}
80
81	static int serial8250_em_serial_dl_read(struct uart_8250_port *up)
82	{
83	return serial_in(up, UART_DLL_EM) \| serial_in(up, UART_DLM_EM) << 8;
84	}
85
86	static void serial8250_em_serial_dl_write(struct uart_8250_port *up, int value)
87	{
88	serial_out(up, UART_DLL_EM, value & 0xff);
89	serial_out(up, UART_DLM_EM, value >> 8 & 0xff);
90	}
91
9671f099	92	static int serial8250_em_probe(struct platform_device *pdev)
22886ee9 MD	93	{
	94	struct resource *regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	95	struct resource *irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
	96	struct serial8250_em_priv *priv;
	97	struct uart_8250_port up;
299a6257	98	int ret;
22886ee9 MD	99
	100	if (!regs \|\| !irq) {
	101	dev_err(&pdev->dev, "missing registers or irq\n");
299a6257	102	return -EINVAL;
22886ee9 MD	103	}
22886ee9 MD	104
299a6257	105	priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
22886ee9 MD	106	if (!priv) {
22886ee9 MD	107	dev_err(&pdev->dev, "unable to allocate private data\n");
299a6257	108	return -ENOMEM;
22886ee9 MD	109	}
22886ee9 MD	110
299a6257	111	priv->sclk = devm_clk_get(&pdev->dev, "sclk");
94e792ab	112	if (IS_ERR(priv->sclk)) {
22886ee9	113	dev_err(&pdev->dev, "unable to get clock\n");
299a6257	114	return PTR_ERR(priv->sclk);
22886ee9 MD	115	}
	116
	117	memset(&up, 0, sizeof(up));
	118	up.port.mapbase = regs->start;
	119	up.port.irq = irq->start;
	120	up.port.type = PORT_UNKNOWN;
	121	up.port.flags = UPF_BOOT_AUTOCONF \| UPF_FIXED_PORT \| UPF_IOREMAP;
	122	up.port.dev = &pdev->dev;
	123	up.port.private_data = priv;
	124
12082ba2	125	clk_prepare_enable(priv->sclk);
22886ee9 MD	126	up.port.uartclk = clk_get_rate(priv->sclk);
	127
	128	up.port.iotype = UPIO_MEM32;
	129	up.port.serial_in = serial8250_em_serial_in;
	130	up.port.serial_out = serial8250_em_serial_out;
	131	up.dl_read = serial8250_em_serial_dl_read;
	132	up.dl_write = serial8250_em_serial_dl_write;
	133
	134	ret = serial8250_register_8250_port(&up);
	135	if (ret < 0) {
	136	dev_err(&pdev->dev, "unable to register 8250 port\n");
12082ba2	137	clk_disable_unprepare(priv->sclk);
299a6257	138	return ret;
22886ee9 MD	139	}
	140
	141	priv->line = ret;
	142	platform_set_drvdata(pdev, priv);
	143	return 0;
22886ee9 MD	144	}
22886ee9 MD	145
ae8d8a14	146	static int serial8250_em_remove(struct platform_device *pdev)
22886ee9 MD	147	{
	148	struct serial8250_em_priv *priv = platform_get_drvdata(pdev);
	149
	150	serial8250_unregister_port(priv->line);
12082ba2	151	clk_disable_unprepare(priv->sclk);
22886ee9 MD	152	return 0;
	153	}
	154
512f82a0	155	static const struct of_device_id serial8250_em_dt_ids[] = {
3e62c413 MD	156	{ .compatible = "renesas,em-uart", },
	157	{},
	158	};
	159	MODULE_DEVICE_TABLE(of, serial8250_em_dt_ids);
	160
22886ee9 MD	161	static struct platform_driver serial8250_em_platform_driver = {
	162	.driver = {
	163	.name = "serial8250-em",
3e62c413	164	.of_match_table = serial8250_em_dt_ids,
22886ee9 MD	165	.owner = THIS_MODULE,
	166	},
	167	.probe = serial8250_em_probe,
2d47b716	168	.remove = serial8250_em_remove,
22886ee9 MD	169	};
	170
	171	module_platform_driver(serial8250_em_platform_driver);
	172
	173	MODULE_AUTHOR("Magnus Damm");
	174	MODULE_DESCRIPTION("Renesas Emma Mobile 8250 Driver");
	175	MODULE_LICENSE("GPL v2");