[linux-2.6-block.git] / drivers / misc / vexpress-syscfg.c

/*
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * 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.
 *
 * Copyright (C) 2014 ARM Limited
 */

#include <linux/delay.h>
#include <linux/err.h>
#include <linux/io.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/sched/signal.h>
#include <linux/slab.h>
#include <linux/syscore_ops.h>
#include <linux/vexpress.h>


#define SYS_CFGDATA		0x0

#define SYS_CFGCTRL		0x4
#define SYS_CFGCTRL_START	(1 << 31)
#define SYS_CFGCTRL_WRITE	(1 << 30)
#define SYS_CFGCTRL_DCC(n)	(((n) & 0xf) << 26)
#define SYS_CFGCTRL_FUNC(n)	(((n) & 0x3f) << 20)
#define SYS_CFGCTRL_SITE(n)	(((n) & 0x3) << 16)
#define SYS_CFGCTRL_POSITION(n)	(((n) & 0xf) << 12)
#define SYS_CFGCTRL_DEVICE(n)	(((n) & 0xfff) << 0)

#define SYS_CFGSTAT		0x8
#define SYS_CFGSTAT_ERR		(1 << 1)
#define SYS_CFGSTAT_COMPLETE	(1 << 0)


struct vexpress_syscfg {
	struct device *dev;
	void __iomem *base;
	struct list_head funcs;
};

struct vexpress_syscfg_func {
	struct list_head list;
	struct vexpress_syscfg *syscfg;
	struct regmap *regmap;
	int num_templates;
	u32 template[0]; /* Keep it last! */
};


static int vexpress_syscfg_exec(struct vexpress_syscfg_func *func,
		int index, bool write, u32 *data)
{
	struct vexpress_syscfg *syscfg = func->syscfg;
	u32 command, status;
	int tries;
	long timeout;

	if (WARN_ON(index >= func->num_templates))
		return -EINVAL;

	command = readl(syscfg->base + SYS_CFGCTRL);
	if (WARN_ON(command & SYS_CFGCTRL_START))
		return -EBUSY;

	command = func->template[index];
	command |= SYS_CFGCTRL_START;
	command |= write ? SYS_CFGCTRL_WRITE : 0;

	/* Use a canary for reads */
	if (!write)
		*data = 0xdeadbeef;

	dev_dbg(syscfg->dev, "func %p, command %x, data %x\n",
			func, command, *data);
	writel(*data, syscfg->base + SYS_CFGDATA);
	writel(0, syscfg->base + SYS_CFGSTAT);
	writel(command, syscfg->base + SYS_CFGCTRL);
	mb();

	/* The operation can take ages... Go to sleep, 100us initially */
	tries = 100;
	timeout = 100;
	do {
		if (!irqs_disabled()) {
			set_current_state(TASK_INTERRUPTIBLE);
			schedule_timeout(usecs_to_jiffies(timeout));
			if (signal_pending(current))
				return -EINTR;
		} else {
			udelay(timeout);
		}

		status = readl(syscfg->base + SYS_CFGSTAT);
		if (status & SYS_CFGSTAT_ERR)
			return -EFAULT;

		if (timeout > 20)
			timeout -= 20;
	} while (--tries && !(status & SYS_CFGSTAT_COMPLETE));
	if (WARN_ON_ONCE(!tries))
		return -ETIMEDOUT;

	if (!write) {
		*data = readl(syscfg->base + SYS_CFGDATA);
		dev_dbg(syscfg->dev, "func %p, read data %x\n", func, *data);
	}

	return 0;
}

static int vexpress_syscfg_read(void *context, unsigned int index,
		unsigned int *val)
{
	struct vexpress_syscfg_func *func = context;

	return vexpress_syscfg_exec(func, index, false, val);
}

static int vexpress_syscfg_write(void *context, unsigned int index,
		unsigned int val)
{
	struct vexpress_syscfg_func *func = context;

	return vexpress_syscfg_exec(func, index, true, &val);
}

static struct regmap_config vexpress_syscfg_regmap_config = {
	.lock = vexpress_config_lock,
	.unlock = vexpress_config_unlock,
	.reg_bits = 32,
	.val_bits = 32,
	.reg_read = vexpress_syscfg_read,
	.reg_write = vexpress_syscfg_write,
	.reg_format_endian = REGMAP_ENDIAN_LITTLE,
	.val_format_endian = REGMAP_ENDIAN_LITTLE,
};


static struct regmap *vexpress_syscfg_regmap_init(struct device *dev,
		void *context)
{
	int err;
	struct vexpress_syscfg *syscfg = context;
	struct vexpress_syscfg_func *func;
	struct property *prop;
	const __be32 *val = NULL;
	__be32 energy_quirk[4];
	int num;
	u32 site, position, dcc;
	int i;

	err = vexpress_config_get_topo(dev->of_node, &site,
				&position, &dcc);
	if (err)
		return ERR_PTR(err);

	prop = of_find_property(dev->of_node,
			"arm,vexpress-sysreg,func", NULL);
	if (!prop)
		return ERR_PTR(-EINVAL);

	num = prop->length / sizeof(u32) / 2;
	val = prop->value;

	/*
	 * "arm,vexpress-energy" function used to be described
	 * by its first device only, now it requires both
	 */
	if (num == 1 && of_device_is_compatible(dev->of_node,
			"arm,vexpress-energy")) {
		num = 2;
		energy_quirk[0] = *val;
		energy_quirk[2] = *val++;
		energy_quirk[1] = *val;
		energy_quirk[3] = cpu_to_be32(be32_to_cpup(val) + 1);
		val = energy_quirk;
	}

	func = kzalloc(struct_size(func, template, num), GFP_KERNEL);
	if (!func)
		return ERR_PTR(-ENOMEM);

	func->syscfg = syscfg;
	func->num_templates = num;

	for (i = 0; i < num; i++) {
		u32 function, device;

		function = be32_to_cpup(val++);
		device = be32_to_cpup(val++);

		dev_dbg(dev, "func %p: %u/%u/%u/%u/%u\n",
				func, site, position, dcc,
				function, device);

		func->template[i] = SYS_CFGCTRL_DCC(dcc);
		func->template[i] |= SYS_CFGCTRL_SITE(site);
		func->template[i] |= SYS_CFGCTRL_POSITION(position);
		func->template[i] |= SYS_CFGCTRL_FUNC(function);
		func->template[i] |= SYS_CFGCTRL_DEVICE(device);
	}

	vexpress_syscfg_regmap_config.max_register = num - 1;

	func->regmap = regmap_init(dev, NULL, func,
			&vexpress_syscfg_regmap_config);

	if (IS_ERR(func->regmap)) {
		void *err = func->regmap;

		kfree(func);
		return err;
	}

	list_add(&func->list, &syscfg->funcs);

	return func->regmap;
}

static void vexpress_syscfg_regmap_exit(struct regmap *regmap, void *context)
{
	struct vexpress_syscfg *syscfg = context;
	struct vexpress_syscfg_func *func, *tmp;

	regmap_exit(regmap);

	list_for_each_entry_safe(func, tmp, &syscfg->funcs, list) {
		if (func->regmap == regmap) {
			list_del(&syscfg->funcs);
			kfree(func);
			break;
		}
	}
}

static struct vexpress_config_bridge_ops vexpress_syscfg_bridge_ops = {
	.regmap_init = vexpress_syscfg_regmap_init,
	.regmap_exit = vexpress_syscfg_regmap_exit,
};


static int vexpress_syscfg_probe(struct platform_device *pdev)
{
	struct vexpress_syscfg *syscfg;
	struct resource *res;
	struct device *bridge;

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

	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	syscfg->base = devm_ioremap_resource(&pdev->dev, res);
	if (IS_ERR(syscfg->base))
		return PTR_ERR(syscfg->base);

	/* Must use dev.parent (MFD), as that's where DT phandle points at... */
	bridge = vexpress_config_bridge_register(pdev->dev.parent,
			&vexpress_syscfg_bridge_ops, syscfg);

	return PTR_ERR_OR_ZERO(bridge);
}

static const struct platform_device_id vexpress_syscfg_id_table[] = {
	{ "vexpress-syscfg", },
	{},
};

static struct platform_driver vexpress_syscfg_driver = {
	.driver.name = "vexpress-syscfg",
	.id_table = vexpress_syscfg_id_table,
	.probe = vexpress_syscfg_probe,
};

static int __init vexpress_syscfg_init(void)
{
	return platform_driver_register(&vexpress_syscfg_driver);
}
core_initcall(vexpress_syscfg_init);
Commit	Line	Data
974cc7b9 PM	1	/*
	2	* This program is free software; you can redistribute it and/or modify
	3	* it under the terms of the GNU General Public License version 2 as
	4	* published by the Free Software Foundation.
	5	*
	6	* This program is distributed in the hope that it will be useful,
	7	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	8	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	9	* GNU General Public License for more details.
	10	*
	11	* Copyright (C) 2014 ARM Limited
	12	*/
	13
	14	#include <linux/delay.h>
	15	#include <linux/err.h>
	16	#include <linux/io.h>
	17	#include <linux/of.h>
	18	#include <linux/platform_device.h>
174cd4b1	19	#include <linux/sched/signal.h>
974cc7b9 PM	20	#include <linux/slab.h>
	21	#include <linux/syscore_ops.h>
	22	#include <linux/vexpress.h>
	23
	24
	25	#define SYS_CFGDATA 0x0
	26
	27	#define SYS_CFGCTRL 0x4
	28	#define SYS_CFGCTRL_START (1 << 31)
	29	#define SYS_CFGCTRL_WRITE (1 << 30)
	30	#define SYS_CFGCTRL_DCC(n) (((n) & 0xf) << 26)
	31	#define SYS_CFGCTRL_FUNC(n) (((n) & 0x3f) << 20)
	32	#define SYS_CFGCTRL_SITE(n) (((n) & 0x3) << 16)
	33	#define SYS_CFGCTRL_POSITION(n) (((n) & 0xf) << 12)
	34	#define SYS_CFGCTRL_DEVICE(n) (((n) & 0xfff) << 0)
	35
	36	#define SYS_CFGSTAT 0x8
	37	#define SYS_CFGSTAT_ERR (1 << 1)
	38	#define SYS_CFGSTAT_COMPLETE (1 << 0)
	39
	40
	41	struct vexpress_syscfg {
	42	struct device *dev;
	43	void __iomem *base;
	44	struct list_head funcs;
	45	};
	46
	47	struct vexpress_syscfg_func {
	48	struct list_head list;
	49	struct vexpress_syscfg *syscfg;
	50	struct regmap *regmap;
	51	int num_templates;
	52	u32 template[0]; /* Keep it last! */
	53	};
	54
	55
	56	static int vexpress_syscfg_exec(struct vexpress_syscfg_func *func,
	57	int index, bool write, u32 *data)
	58	{
	59	struct vexpress_syscfg *syscfg = func->syscfg;
	60	u32 command, status;
	61	int tries;
	62	long timeout;
	63
f8a70d8b	64	if (WARN_ON(index >= func->num_templates))
974cc7b9 PM	65	return -EINVAL;
	66
	67	command = readl(syscfg->base + SYS_CFGCTRL);
	68	if (WARN_ON(command & SYS_CFGCTRL_START))
	69	return -EBUSY;
	70
	71	command = func->template[index];
	72	command \|= SYS_CFGCTRL_START;
	73	command \|= write ? SYS_CFGCTRL_WRITE : 0;
	74
	75	/* Use a canary for reads */
	76	if (!write)
	77	*data = 0xdeadbeef;
	78
	79	dev_dbg(syscfg->dev, "func %p, command %x, data %x\n",
	80	func, command, *data);
	81	writel(*data, syscfg->base + SYS_CFGDATA);
	82	writel(0, syscfg->base + SYS_CFGSTAT);
	83	writel(command, syscfg->base + SYS_CFGCTRL);
	84	mb();
	85
	86	/* The operation can take ages... Go to sleep, 100us initially */
	87	tries = 100;
	88	timeout = 100;
	89	do {
	90	if (!irqs_disabled()) {
	91	set_current_state(TASK_INTERRUPTIBLE);
	92	schedule_timeout(usecs_to_jiffies(timeout));
	93	if (signal_pending(current))
	94	return -EINTR;
	95	} else {
	96	udelay(timeout);
	97	}
	98
	99	status = readl(syscfg->base + SYS_CFGSTAT);
	100	if (status & SYS_CFGSTAT_ERR)
	101	return -EFAULT;
	102
	103	if (timeout > 20)
	104	timeout -= 20;
	105	} while (--tries && !(status & SYS_CFGSTAT_COMPLETE));
	106	if (WARN_ON_ONCE(!tries))
	107	return -ETIMEDOUT;
	108
	109	if (!write) {
	110	*data = readl(syscfg->base + SYS_CFGDATA);
	111	dev_dbg(syscfg->dev, "func %p, read data %x\n", func, *data);
	112	}
	113
	114	return 0;
	115	}
	116
	117	static int vexpress_syscfg_read(void *context, unsigned int index,
	118	unsigned int *val)
	119	{
	120	struct vexpress_syscfg_func *func = context;
	121
	122	return vexpress_syscfg_exec(func, index, false, val);
	123	}
	124
	125	static int vexpress_syscfg_write(void *context, unsigned int index,
	126	unsigned int val)
	127	{
	128	struct vexpress_syscfg_func *func = context;
129
130	return vexpress_syscfg_exec(func, index, true, &val);
131	}
132
f222447e	133	static struct regmap_config vexpress_syscfg_regmap_config = {
974cc7b9 PM	134	.lock = vexpress_config_lock,
	135	.unlock = vexpress_config_unlock,
	136	.reg_bits = 32,
	137	.val_bits = 32,
	138	.reg_read = vexpress_syscfg_read,
	139	.reg_write = vexpress_syscfg_write,
	140	.reg_format_endian = REGMAP_ENDIAN_LITTLE,
	141	.val_format_endian = REGMAP_ENDIAN_LITTLE,
	142	};
	143
	144
	145	static struct regmap vexpress_syscfg_regmap_init(struct device dev,
	146	void *context)
	147	{
81cc3f86	148	int err;
974cc7b9 PM	149	struct vexpress_syscfg *syscfg = context;
	150	struct vexpress_syscfg_func *func;
	151	struct property *prop;
	152	const __be32 *val = NULL;
	153	__be32 energy_quirk[4];
	154	int num;
	155	u32 site, position, dcc;
	156	int i;
	157
81cc3f86	158	err = vexpress_config_get_topo(dev->of_node, &site,
974cc7b9	159	&position, &dcc);
81cc3f86 PM	160	if (err)
81cc3f86 PM	161	return ERR_PTR(err);
974cc7b9	162
81cc3f86 PM	163	prop = of_find_property(dev->of_node,
	164	"arm,vexpress-sysreg,func", NULL);
	165	if (!prop)
	166	return ERR_PTR(-EINVAL);
	167
	168	num = prop->length / sizeof(u32) / 2;
	169	val = prop->value;
974cc7b9 PM	170
	171	/*
	172	* "arm,vexpress-energy" function used to be described
	173	* by its first device only, now it requires both
	174	*/
	175	if (num == 1 && of_device_is_compatible(dev->of_node,
	176	"arm,vexpress-energy")) {
	177	num = 2;
	178	energy_quirk[0] = *val;
	179	energy_quirk[2] = *val++;
	180	energy_quirk[1] = *val;
	181	energy_quirk[3] = cpu_to_be32(be32_to_cpup(val) + 1);
	182	val = energy_quirk;
	183	}
	184
acafe7e3	185	func = kzalloc(struct_size(func, template, num), GFP_KERNEL);
974cc7b9	186	if (!func)
b86e1926	187	return ERR_PTR(-ENOMEM);
974cc7b9 PM	188
	189	func->syscfg = syscfg;
	190	func->num_templates = num;
	191
	192	for (i = 0; i < num; i++) {
	193	u32 function, device;
	194
81cc3f86 PM	195	function = be32_to_cpup(val++);
81cc3f86 PM	196	device = be32_to_cpup(val++);
974cc7b9 PM	197
	198	dev_dbg(dev, "func %p: %u/%u/%u/%u/%u\n",
	199	func, site, position, dcc,
	200	function, device);
	201
	202	func->template[i] = SYS_CFGCTRL_DCC(dcc);
	203	func->template[i] \|= SYS_CFGCTRL_SITE(site);
	204	func->template[i] \|= SYS_CFGCTRL_POSITION(position);
	205	func->template[i] \|= SYS_CFGCTRL_FUNC(function);
	206	func->template[i] \|= SYS_CFGCTRL_DEVICE(device);
	207	}
	208
	209	vexpress_syscfg_regmap_config.max_register = num - 1;
	210
	211	func->regmap = regmap_init(dev, NULL, func,
	212	&vexpress_syscfg_regmap_config);
	213
b86e1926 DC	214	if (IS_ERR(func->regmap)) {
	215	void *err = func->regmap;
	216
974cc7b9	217	kfree(func);
b86e1926 DC	218	return err;
	219	}
	220
	221	list_add(&func->list, &syscfg->funcs);
974cc7b9 PM	222
	223	return func->regmap;
	224	}
	225
	226	static void vexpress_syscfg_regmap_exit(struct regmap regmap, void context)
	227	{
	228	struct vexpress_syscfg *syscfg = context;
	229	struct vexpress_syscfg_func func, tmp;
	230
	231	regmap_exit(regmap);
	232
	233	list_for_each_entry_safe(func, tmp, &syscfg->funcs, list) {
	234	if (func->regmap == regmap) {
	235	list_del(&syscfg->funcs);
	236	kfree(func);
	237	break;
	238	}
	239	}
	240	}
	241
	242	static struct vexpress_config_bridge_ops vexpress_syscfg_bridge_ops = {
	243	.regmap_init = vexpress_syscfg_regmap_init,
	244	.regmap_exit = vexpress_syscfg_regmap_exit,
	245	};
	246
	247
f222447e	248	static int vexpress_syscfg_probe(struct platform_device *pdev)
974cc7b9 PM	249	{
	250	struct vexpress_syscfg *syscfg;
	251	struct resource *res;
	252	struct device *bridge;
	253
	254	syscfg = devm_kzalloc(&pdev->dev, sizeof(*syscfg), GFP_KERNEL);
	255	if (!syscfg)
	256	return -ENOMEM;
	257	syscfg->dev = &pdev->dev;
	258	INIT_LIST_HEAD(&syscfg->funcs);
	259
	260	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
555e7943 SH	261	syscfg->base = devm_ioremap_resource(&pdev->dev, res);
	262	if (IS_ERR(syscfg->base))
	263	return PTR_ERR(syscfg->base);
974cc7b9 PM	264
	265	/* Must use dev.parent (MFD), as that's where DT phandle points at... */
	266	bridge = vexpress_config_bridge_register(pdev->dev.parent,
	267	&vexpress_syscfg_bridge_ops, syscfg);
974cc7b9	268
eecf4f9d	269	return PTR_ERR_OR_ZERO(bridge);
974cc7b9 PM	270	}
	271
	272	static const struct platform_device_id vexpress_syscfg_id_table[] = {
	273	{ "vexpress-syscfg", },
	274	{},
	275	};
	276
	277	static struct platform_driver vexpress_syscfg_driver = {
	278	.driver.name = "vexpress-syscfg",
	279	.id_table = vexpress_syscfg_id_table,
	280	.probe = vexpress_syscfg_probe,
	281	};
	282
	283	static int __init vexpress_syscfg_init(void)
	284	{
	285	return platform_driver_register(&vexpress_syscfg_driver);
	286	}
	287	core_initcall(vexpress_syscfg_init);