[deliverable/linux.git] / drivers / platform / x86 / ibm_rtl.c

/*
 * IBM Real-Time Linux driver
 *
 * 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, or
 * (at your option) any later version.
 *
 * 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.
 *
 * Copyright (C) IBM Corporation, 2010
 *
 * Author: Keith Mannthey <kmannth@us.ibm.com>
 *         Vernon Mauery <vernux@us.ibm.com>
 *
 */

#include <linux/kernel.h>
#include <linux/delay.h>
#include <linux/module.h>
#include <linux/io.h>
#include <linux/sysdev.h>
#include <linux/dmi.h>
#include <linux/efi.h>
#include <linux/mutex.h>
#include <asm/bios_ebda.h>

static bool force;
module_param(force, bool, 0);
MODULE_PARM_DESC(force, "Force driver load, ignore DMI data");

static bool debug;
module_param(debug, bool, 0644);
MODULE_PARM_DESC(debug, "Show debug output");

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Keith Mannthey <kmmanth@us.ibm.com>");
MODULE_AUTHOR("Vernon Mauery <vernux@us.ibm.com>");

#define RTL_ADDR_TYPE_IO    1
#define RTL_ADDR_TYPE_MMIO  2

#define RTL_CMD_ENTER_PRTM  1
#define RTL_CMD_EXIT_PRTM   2

/* The RTL table as presented by the EBDA: */
struct ibm_rtl_table {
	char signature[5]; /* signature should be "_RTL_" */
	u8 version;
	u8 rt_status;
	u8 command;
	u8 command_status;
	u8 cmd_address_type;
	u8 cmd_granularity;
	u8 cmd_offset;
	u16 reserve1;
	u32 cmd_port_address; /* platform dependent address */
	u32 cmd_port_value;   /* platform dependent value */
} __attribute__((packed));

/* to locate "_RTL_" signature do a masked 5-byte integer compare */
#define RTL_SIGNATURE 0x0000005f4c54525fULL
#define RTL_MASK      0x000000ffffffffffULL

#define RTL_DEBUG(A, ...) do { \
	if (debug) \
		pr_info("ibm-rtl: " A, ##__VA_ARGS__ ); \
} while (0)

static DEFINE_MUTEX(rtl_lock);
static struct ibm_rtl_table __iomem *rtl_table;
static void __iomem *ebda_map;
static void __iomem *rtl_cmd_addr;
static u8 rtl_cmd_type;
static u8 rtl_cmd_width;

static void __iomem *rtl_port_map(phys_addr_t addr, unsigned long len)
{
	if (rtl_cmd_type == RTL_ADDR_TYPE_MMIO)
		return ioremap(addr, len);
	return ioport_map(addr, len);
}

static void rtl_port_unmap(void __iomem *addr)
{
	if (addr && rtl_cmd_type == RTL_ADDR_TYPE_MMIO)
		iounmap(addr);
	else
		ioport_unmap(addr);
}

static int ibm_rtl_write(u8 value)
{
	int ret = 0, count = 0;
	static u32 cmd_port_val;

	RTL_DEBUG("%s(%d)\n", __FUNCTION__, value);

	value = value == 1 ? RTL_CMD_ENTER_PRTM : RTL_CMD_EXIT_PRTM;

	mutex_lock(&rtl_lock);

	if (ioread8(&rtl_table->rt_status) != value) {
		iowrite8(value, &rtl_table->command);

		switch (rtl_cmd_width) {
		case 8:
			cmd_port_val = ioread8(&rtl_table->cmd_port_value);
			RTL_DEBUG("cmd_port_val = %u\n", cmd_port_val);
			iowrite8((u8)cmd_port_val, rtl_cmd_addr);
			break;
		case 16:
			cmd_port_val = ioread16(&rtl_table->cmd_port_value);
			RTL_DEBUG("cmd_port_val = %u\n", cmd_port_val);
			iowrite16((u16)cmd_port_val, rtl_cmd_addr);
			break;
		case 32:
			cmd_port_val = ioread32(&rtl_table->cmd_port_value);
			RTL_DEBUG("cmd_port_val = %u\n", cmd_port_val);
			iowrite32(cmd_port_val, rtl_cmd_addr);
			break;
		}

		while (ioread8(&rtl_table->command)) {
			msleep(10);
			if (count++ > 500) {
				pr_err("ibm-rtl: Hardware not responding to "
					"mode switch request\n");
				ret = -EIO;
				break;
			}

		}

		if (ioread8(&rtl_table->command_status)) {
			RTL_DEBUG("command_status reports failed command\n");
			ret = -EIO;
		}
	}

	mutex_unlock(&rtl_lock);
	return ret;
}

static ssize_t rtl_show_version(struct sysdev_class * dev,
                                struct sysdev_class_attribute *attr,
                                char *buf)
{
	return sprintf(buf, "%d\n", (int)ioread8(&rtl_table->version));
}

static ssize_t rtl_show_state(struct sysdev_class *dev,
                              struct sysdev_class_attribute *attr,
                              char *buf)
{
	return sprintf(buf, "%d\n", ioread8(&rtl_table->rt_status));
}

static ssize_t rtl_set_state(struct sysdev_class *dev,
                             struct sysdev_class_attribute *attr,
                             const char *buf,
                             size_t count)
{
	ssize_t ret;

	if (count < 1 || count > 2)
		return -EINVAL;

	switch (buf[0]) {
	case '0':
		ret = ibm_rtl_write(0);
		break;
	case '1':
		ret = ibm_rtl_write(1);
		break;
	default:
		ret = -EINVAL;
	}
	if (ret >= 0)
		ret = count;

	return ret;
}

static struct sysdev_class class_rtl = {
	.name = "ibm_rtl",
};

static SYSDEV_CLASS_ATTR(version, S_IRUGO, rtl_show_version, NULL);
static SYSDEV_CLASS_ATTR(state, 0600, rtl_show_state, rtl_set_state);

static struct sysdev_class_attribute *rtl_attributes[] = {
	&attr_version,
	&attr_state,
	NULL
};


static int rtl_setup_sysfs(void) {
	int ret, i;
	ret = sysdev_class_register(&class_rtl);

	if (!ret) {
		for (i = 0; rtl_attributes[i]; i ++)
			sysdev_class_create_file(&class_rtl, rtl_attributes[i]);
	}
	return ret;
}

static void rtl_teardown_sysfs(void) {
	int i;
	for (i = 0; rtl_attributes[i]; i ++)
		sysdev_class_remove_file(&class_rtl, rtl_attributes[i]);
	sysdev_class_unregister(&class_rtl);
}


static struct dmi_system_id __initdata ibm_rtl_dmi_table[] = {
	{                                                  \
		.matches = {                               \
			DMI_MATCH(DMI_SYS_VENDOR, "IBM"),  \
		},                                         \
	},
	{ }
};

static int __init ibm_rtl_init(void) {
	unsigned long ebda_addr, ebda_size;
	unsigned int ebda_kb;
	int ret = -ENODEV, i;

	if (force)
		pr_warning("ibm-rtl: module loaded by force\n");
	/* first ensure that we are running on IBM HW */
	else if (efi_enabled || !dmi_check_system(ibm_rtl_dmi_table))
		return -ENODEV;

	/* Get the address for the Extended BIOS Data Area */
	ebda_addr = get_bios_ebda();
	if (!ebda_addr) {
		RTL_DEBUG("no BIOS EBDA found\n");
		return -ENODEV;
	}

	ebda_map = ioremap(ebda_addr, 4);
	if (!ebda_map)
		return -ENOMEM;

	/* First word in the EDBA is the Size in KB */
	ebda_kb = ioread16(ebda_map);
	RTL_DEBUG("EBDA is %d kB\n", ebda_kb);

	if (ebda_kb == 0)
		goto out;

	iounmap(ebda_map);
	ebda_size = ebda_kb*1024;

	/* Remap the whole table */
	ebda_map = ioremap(ebda_addr, ebda_size);
	if (!ebda_map)
		return -ENOMEM;

	/* search for the _RTL_ signature at the start of the table */
	for (i = 0 ; i < ebda_size/sizeof(unsigned int); i++) {
		struct ibm_rtl_table __iomem * tmp;
		tmp = (struct ibm_rtl_table __iomem *) (ebda_map+i);
		if ((readq(&tmp->signature) & RTL_MASK) == RTL_SIGNATURE) {
			phys_addr_t addr;
			unsigned int plen;
			RTL_DEBUG("found RTL_SIGNATURE at %#llx\n", (u64)tmp);
			rtl_table = tmp;
			/* The address, value, width and offset are platform
			 * dependent and found in the ibm_rtl_table */
			rtl_cmd_width = ioread8(&rtl_table->cmd_granularity);
			rtl_cmd_type = ioread8(&rtl_table->cmd_address_type);
			RTL_DEBUG("rtl_cmd_width = %u, rtl_cmd_type = %u\n",
			      rtl_cmd_width, rtl_cmd_type);
			addr = ioread32(&rtl_table->cmd_port_address);
			RTL_DEBUG("addr = %#llx\n", (unsigned long long)addr);
			plen = rtl_cmd_width/sizeof(char);
			rtl_cmd_addr = rtl_port_map(addr, plen);
			RTL_DEBUG("rtl_cmd_addr = %#llx\n", (u64)rtl_cmd_addr);
			if (!rtl_cmd_addr) {
				ret = -ENOMEM;
				break;
			}
			ret = rtl_setup_sysfs();
			break;
		}
	}

out:
	if (ret) {
		iounmap(ebda_map);
		rtl_port_unmap(rtl_cmd_addr);
	}

	return ret;
}

static void __exit ibm_rtl_exit(void)
{
	if (rtl_table) {
		RTL_DEBUG("cleaning up");
		/* do not leave the machine in SMI-free mode */
		ibm_rtl_write(0);
		/* unmap, unlink and remove all traces */
		rtl_teardown_sysfs();
		iounmap(ebda_map);
		rtl_port_unmap(rtl_cmd_addr);
	}
}

module_init(ibm_rtl_init);
module_exit(ibm_rtl_exit);
Commit	Line	Data
35f0ce03 VM	1	/*
	2	* IBM Real-Time Linux driver
	3	*
	4	* This program is free software; you can redistribute it and/or modify
	5	* it under the terms of the GNU General Public License as published by
	6	* the Free Software Foundation; either version 2 of the License, or
	7	* (at your option) any later version.
	8	*
	9	* This program is distributed in the hope that it will be useful,
	10	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	11	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	12	* GNU General Public License for more details.
	13	*
	14	* You should have received a copy of the GNU General Public License
	15	* along with this program; if not, write to the Free Software
	16	* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
	17	*
	18	* Copyright (C) IBM Corporation, 2010
	19	*
	20	* Author: Keith Mannthey <kmannth@us.ibm.com>
	21	* Vernon Mauery <vernux@us.ibm.com>
	22	*
	23	*/
	24
	25	#include <linux/kernel.h>
	26	#include <linux/delay.h>
	27	#include <linux/module.h>
	28	#include <linux/io.h>
	29	#include <linux/sysdev.h>
	30	#include <linux/dmi.h>
1d37db77	31	#include <linux/efi.h>
35f0ce03 VM	32	#include <linux/mutex.h>
	33	#include <asm/bios_ebda.h>
	34
	35	static bool force;
	36	module_param(force, bool, 0);
	37	MODULE_PARM_DESC(force, "Force driver load, ignore DMI data");
	38
	39	static bool debug;
	40	module_param(debug, bool, 0644);
	41	MODULE_PARM_DESC(debug, "Show debug output");
	42
	43	MODULE_LICENSE("GPL");
	44	MODULE_AUTHOR("Keith Mannthey <kmmanth@us.ibm.com>");
	45	MODULE_AUTHOR("Vernon Mauery <vernux@us.ibm.com>");
	46
	47	#define RTL_ADDR_TYPE_IO 1
	48	#define RTL_ADDR_TYPE_MMIO 2
	49
	50	#define RTL_CMD_ENTER_PRTM 1
	51	#define RTL_CMD_EXIT_PRTM 2
	52
	53	/* The RTL table as presented by the EBDA: */
	54	struct ibm_rtl_table {
	55	char signature[5]; /* signature should be "_RTL_" */
	56	u8 version;
	57	u8 rt_status;
	58	u8 command;
	59	u8 command_status;
	60	u8 cmd_address_type;
	61	u8 cmd_granularity;
	62	u8 cmd_offset;
	63	u16 reserve1;
	64	u32 cmd_port_address; /* platform dependent address */
	65	u32 cmd_port_value; /* platform dependent value */
	66	} __attribute__((packed));
	67
	68	/* to locate "_RTL_" signature do a masked 5-byte integer compare */
	69	#define RTL_SIGNATURE 0x0000005f4c54525fULL
	70	#define RTL_MASK 0x000000ffffffffffULL
	71
	72	#define RTL_DEBUG(A, ...) do { \
	73	if (debug) \
	74	pr_info("ibm-rtl: " A, ##__VA_ARGS__ ); \
	75	} while (0)
	76
	77	static DEFINE_MUTEX(rtl_lock);
	78	static struct ibm_rtl_table __iomem *rtl_table;
	79	static void __iomem *ebda_map;
	80	static void __iomem *rtl_cmd_addr;
	81	static u8 rtl_cmd_type;
	82	static u8 rtl_cmd_width;
	83
	84	static void __iomem *rtl_port_map(phys_addr_t addr, unsigned long len)
	85	{
	86	if (rtl_cmd_type == RTL_ADDR_TYPE_MMIO)
	87	return ioremap(addr, len);
	88	return ioport_map(addr, len);
	89	}
	90
	91	static void rtl_port_unmap(void __iomem *addr)
	92	{
	93	if (addr && rtl_cmd_type == RTL_ADDR_TYPE_MMIO)
	94	iounmap(addr);
	95	else
96	ioport_unmap(addr);
97	}
98
99	static int ibm_rtl_write(u8 value)
100	{
101	int ret = 0, count = 0;
102	static u32 cmd_port_val;
103
104	RTL_DEBUG("%s(%d)\n", __FUNCTION__, value);
105
106	value = value == 1 ? RTL_CMD_ENTER_PRTM : RTL_CMD_EXIT_PRTM;
107
108	mutex_lock(&rtl_lock);
109
110	if (ioread8(&rtl_table->rt_status) != value) {
111	iowrite8(value, &rtl_table->command);
112
113	switch (rtl_cmd_width) {
114	case 8:
115	cmd_port_val = ioread8(&rtl_table->cmd_port_value);
116	RTL_DEBUG("cmd_port_val = %u\n", cmd_port_val);
117	iowrite8((u8)cmd_port_val, rtl_cmd_addr);
118	break;
119	case 16:
120	cmd_port_val = ioread16(&rtl_table->cmd_port_value);
121	RTL_DEBUG("cmd_port_val = %u\n", cmd_port_val);
122	iowrite16((u16)cmd_port_val, rtl_cmd_addr);
123	break;
124	case 32:
125	cmd_port_val = ioread32(&rtl_table->cmd_port_value);
126	RTL_DEBUG("cmd_port_val = %u\n", cmd_port_val);
127	iowrite32(cmd_port_val, rtl_cmd_addr);
128	break;
129	}
130
131	while (ioread8(&rtl_table->command)) {
132	msleep(10);
133	if (count++ > 500) {
134	pr_err("ibm-rtl: Hardware not responding to "
135	"mode switch request\n");
136	ret = -EIO;
137	break;
138	}
139
140	}
141
142	if (ioread8(&rtl_table->command_status)) {
143	RTL_DEBUG("command_status reports failed command\n");
144	ret = -EIO;
145	}
146	}
147
148	mutex_unlock(&rtl_lock);
149	return ret;
150	}
151
152	static ssize_t rtl_show_version(struct sysdev_class * dev,
153	struct sysdev_class_attribute *attr,
154	char *buf)
155	{
156	return sprintf(buf, "%d\n", (int)ioread8(&rtl_table->version));
157	}
158
159	static ssize_t rtl_show_state(struct sysdev_class *dev,
160	struct sysdev_class_attribute *attr,
161	char *buf)
162	{
163	return sprintf(buf, "%d\n", ioread8(&rtl_table->rt_status));
164	}
165
166	static ssize_t rtl_set_state(struct sysdev_class *dev,
167	struct sysdev_class_attribute *attr,
168	const char *buf,
169	size_t count)
170	{
171	ssize_t ret;
172
173	if (count < 1 \|\| count > 2)
174	return -EINVAL;
175
176	switch (buf[0]) {
177	case '0':
178	ret = ibm_rtl_write(0);
179	break;
180	case '1':
181	ret = ibm_rtl_write(1);
182	break;
183	default:
184	ret = -EINVAL;
185	}
186	if (ret >= 0)
187	ret = count;
188
189	return ret;
190	}
191
192	static struct sysdev_class class_rtl = {
193	.name = "ibm_rtl",
194	};
195
196	static SYSDEV_CLASS_ATTR(version, S_IRUGO, rtl_show_version, NULL);
197	static SYSDEV_CLASS_ATTR(state, 0600, rtl_show_state, rtl_set_state);
198
199	static struct sysdev_class_attribute *rtl_attributes[] = {
200	&attr_version,
201	&attr_state,
202	NULL
203	};
204
205
206	static int rtl_setup_sysfs(void) {
207	int ret, i;
208	ret = sysdev_class_register(&class_rtl);
209
210	if (!ret) {
211	for (i = 0; rtl_attributes[i]; i ++)
212	sysdev_class_create_file(&class_rtl, rtl_attributes[i]);
213	}
214	return ret;
215	}
216
217	static void rtl_teardown_sysfs(void) {
218	int i;
219	for (i = 0; rtl_attributes[i]; i ++)
220	sysdev_class_remove_file(&class_rtl, rtl_attributes[i]);
221	sysdev_class_unregister(&class_rtl);
222	}
223
35f0ce03 VM	224
35f0ce03 VM	225	static struct dmi_system_id __initdata ibm_rtl_dmi_table[] = {
a2262260 VM	226	{ \
	227	.matches = { \
	228	DMI_MATCH(DMI_SYS_VENDOR, "IBM"), \
	229	}, \
	230	},
35f0ce03 VM	231	{ }
	232	};
	233
	234	static int __init ibm_rtl_init(void) {
	235	unsigned long ebda_addr, ebda_size;
	236	unsigned int ebda_kb;
	237	int ret = -ENODEV, i;
	238
	239	if (force)
	240	pr_warning("ibm-rtl: module loaded by force\n");
	241	/* first ensure that we are running on IBM HW */
1d37db77	242	else if (efi_enabled \|\| !dmi_check_system(ibm_rtl_dmi_table))
35f0ce03 VM	243	return -ENODEV;
	244
	245	/* Get the address for the Extended BIOS Data Area */
	246	ebda_addr = get_bios_ebda();
	247	if (!ebda_addr) {
	248	RTL_DEBUG("no BIOS EBDA found\n");
	249	return -ENODEV;
	250	}
	251
	252	ebda_map = ioremap(ebda_addr, 4);
	253	if (!ebda_map)
	254	return -ENOMEM;
	255
	256	/* First word in the EDBA is the Size in KB */
	257	ebda_kb = ioread16(ebda_map);
	258	RTL_DEBUG("EBDA is %d kB\n", ebda_kb);
	259
	260	if (ebda_kb == 0)
	261	goto out;
	262
	263	iounmap(ebda_map);
	264	ebda_size = ebda_kb*1024;
	265
	266	/* Remap the whole table */
	267	ebda_map = ioremap(ebda_addr, ebda_size);
	268	if (!ebda_map)
	269	return -ENOMEM;
	270
	271	/* search for the _RTL_ signature at the start of the table */
	272	for (i = 0 ; i < ebda_size/sizeof(unsigned int); i++) {
	273	struct ibm_rtl_table __iomem * tmp;
	274	tmp = (struct ibm_rtl_table __iomem *) (ebda_map+i);
	275	if ((readq(&tmp->signature) & RTL_MASK) == RTL_SIGNATURE) {
	276	phys_addr_t addr;
	277	unsigned int plen;
	278	RTL_DEBUG("found RTL_SIGNATURE at %#llx\n", (u64)tmp);
	279	rtl_table = tmp;
	280	/* The address, value, width and offset are platform
	281	* dependent and found in the ibm_rtl_table */
	282	rtl_cmd_width = ioread8(&rtl_table->cmd_granularity);
	283	rtl_cmd_type = ioread8(&rtl_table->cmd_address_type);
	284	RTL_DEBUG("rtl_cmd_width = %u, rtl_cmd_type = %u\n",
	285	rtl_cmd_width, rtl_cmd_type);
	286	addr = ioread32(&rtl_table->cmd_port_address);
c72b844e	287	RTL_DEBUG("addr = %#llx\n", (unsigned long long)addr);
35f0ce03 VM	288	plen = rtl_cmd_width/sizeof(char);
	289	rtl_cmd_addr = rtl_port_map(addr, plen);
	290	RTL_DEBUG("rtl_cmd_addr = %#llx\n", (u64)rtl_cmd_addr);
	291	if (!rtl_cmd_addr) {
	292	ret = -ENOMEM;
	293	break;
	294	}
	295	ret = rtl_setup_sysfs();
	296	break;
	297	}
	298	}
	299
	300	out:
	301	if (ret) {
	302	iounmap(ebda_map);
	303	rtl_port_unmap(rtl_cmd_addr);
	304	}
	305
	306	return ret;
	307	}
	308
	309	static void __exit ibm_rtl_exit(void)
	310	{
	311	if (rtl_table) {
	312	RTL_DEBUG("cleaning up");
	313	/* do not leave the machine in SMI-free mode */
	314	ibm_rtl_write(0);
	315	/* unmap, unlink and remove all traces */
	316	rtl_teardown_sysfs();
	317	iounmap(ebda_map);
	318	rtl_port_unmap(rtl_cmd_addr);
	319	}
	320	}
	321
	322	module_init(ibm_rtl_init);
	323	module_exit(ibm_rtl_exit);