[J-u-boot.git] / drivers / misc / vexpress_config.c

// SPDX-License-Identifier: GPL-2.0+
/*
 * Copyright (C) 2018 Arm Ltd
 * Author: Liviu Dudau <[email protected]>
 *
 */
#include <dm.h>
#include <malloc.h>
#include <dm/read.h>
#include <asm/io.h>
#include <linux/bitops.h>
#include <linux/delay.h>
#include <misc.h>

#define SYS_CFGDATA		0xa0

#define SYS_CFGCTRL		0xa4
#define SYS_CFGCTRL_START	BIT(31)
#define SYS_CFGCTRL_WRITE	BIT(30)

#define SYS_CFGSTAT		0xa8
#define SYS_CFGSTAT_ERR		BIT(1)
#define SYS_CFGSTAT_COMPLETE	BIT(0)

struct vexpress_config_sysreg {
	phys_addr_t addr;
	u32 site;
};

static int vexpress_config_exec(struct vexpress_config_sysreg *syscfg,
				bool write, void *buf, int size)
{
	u32 cmd, status, tries = 100;

	cmd = (*(u32 *)buf) | SYS_CFGCTRL_START | (syscfg->site << 16);

	if (!write) {
		/* write a canary in the data register for reads */
		writel(0xdeadbeef, syscfg->addr + SYS_CFGDATA);
	} else {
		cmd |= SYS_CFGCTRL_WRITE;
		writel(((u32 *)buf)[1], syscfg->addr + SYS_CFGDATA);
	}
	writel(0, syscfg->addr + SYS_CFGSTAT);
	writel(cmd, syscfg->addr + SYS_CFGCTRL);

	/* completion of command takes ages, go to sleep (150us) */
	do {
		udelay(150);
		status = readl(syscfg->addr + SYS_CFGSTAT);
		if (status & SYS_CFGSTAT_ERR)
			return -EFAULT;
	} while (--tries && !(status & SYS_CFGSTAT_COMPLETE));

	if (!tries)
		return -ETIMEDOUT;

	if (!write)
		(*(u32 *)buf) = readl(syscfg->addr + SYS_CFGDATA);

	return 0;
}

static int vexpress_config_read(struct udevice *dev,
				int offset, void *buf, int size)
{
	struct vexpress_config_sysreg *priv = dev_get_uclass_priv(dev);

	if (size != sizeof(u32))
		return -EINVAL;

	return vexpress_config_exec(priv, false, buf, size);
}

static int vexpress_config_write(struct udevice *dev,
				 int offset, const void *buf, int size)
{
	struct vexpress_config_sysreg *priv = dev_get_uclass_priv(dev);

	if (size != sizeof(u32) * 2)
		return -EINVAL;

	return vexpress_config_exec(priv, true, (void *)buf, size);
}

static struct misc_ops vexpress_config_ops = {
	.read = vexpress_config_read,
	.write = vexpress_config_write,
};

static int vexpress_config_probe(struct udevice *dev)
{
	struct ofnode_phandle_args args;
	struct vexpress_config_sysreg *priv = dev_get_priv(dev);
	const char *prop;
	int err, prop_size;

	err = dev_read_phandle_with_args(dev, "arm,vexpress,config-bridge",
					 NULL, 0, 0, &args);
	if (err)
		return err;

	prop = ofnode_get_property(args.node, "compatible", &prop_size);
	if (!prop || (strncmp(prop, "arm,vexpress-sysreg", 19) != 0))
		return -ENOENT;

	if (!priv)
		return -ENOMEM;

	priv->addr = ofnode_get_addr(args.node);

	return dev_read_u32(dev, "arm,vexpress,site", &priv->site);
}

static const struct udevice_id vexpress_config_ids[] = {
	{ .compatible = "arm,vexpress,config-bus" },
	{ }
};

U_BOOT_DRIVER(vexpress_config_drv) = {
	.name = "vexpress_config_bus",
	.id = UCLASS_MISC,
	.of_match = vexpress_config_ids,
	.bind = dm_scan_fdt_dev,
	.probe = vexpress_config_probe,
	.ops = &vexpress_config_ops,
	.priv_auto = sizeof(struct vexpress_config_sysreg),
};
Commit	Line	Data
0fabfeb2 LD	1	// SPDX-License-Identifier: GPL-2.0+
	2	/*
	3	* Copyright (C) 2018 Arm Ltd
	4	* Author: Liviu Dudau <[email protected]>
	5	*
	6	*/
0fabfeb2	7	#include <dm.h>
336d4615	8	#include <malloc.h>
0fabfeb2 LD	9	#include <dm/read.h>
0fabfeb2 LD	10	#include <asm/io.h>
cd93d625	11	#include <linux/bitops.h>
0fabfeb2 LD	12	#include <linux/delay.h>
	13	#include <misc.h>
	14
	15	#define SYS_CFGDATA 0xa0
	16
	17	#define SYS_CFGCTRL 0xa4
	18	#define SYS_CFGCTRL_START BIT(31)
	19	#define SYS_CFGCTRL_WRITE BIT(30)
	20
	21	#define SYS_CFGSTAT 0xa8
	22	#define SYS_CFGSTAT_ERR BIT(1)
	23	#define SYS_CFGSTAT_COMPLETE BIT(0)
	24
	25	struct vexpress_config_sysreg {
	26	phys_addr_t addr;
	27	u32 site;
	28	};
	29
	30	static int vexpress_config_exec(struct vexpress_config_sysreg *syscfg,
	31	bool write, void *buf, int size)
	32	{
	33	u32 cmd, status, tries = 100;
	34
	35	cmd = ((u32 )buf) \| SYS_CFGCTRL_START \| (syscfg->site << 16);
	36
	37	if (!write) {
	38	/* write a canary in the data register for reads */
	39	writel(0xdeadbeef, syscfg->addr + SYS_CFGDATA);
	40	} else {
	41	cmd \|= SYS_CFGCTRL_WRITE;
	42	writel(((u32 *)buf)[1], syscfg->addr + SYS_CFGDATA);
	43	}
	44	writel(0, syscfg->addr + SYS_CFGSTAT);
	45	writel(cmd, syscfg->addr + SYS_CFGCTRL);
	46
	47	/* completion of command takes ages, go to sleep (150us) */
	48	do {
	49	udelay(150);
	50	status = readl(syscfg->addr + SYS_CFGSTAT);
	51	if (status & SYS_CFGSTAT_ERR)
	52	return -EFAULT;
	53	} while (--tries && !(status & SYS_CFGSTAT_COMPLETE));
	54
	55	if (!tries)
	56	return -ETIMEDOUT;
	57
	58	if (!write)
	59	((u32 )buf) = readl(syscfg->addr + SYS_CFGDATA);
	60
	61	return 0;
	62	}
	63
	64	static int vexpress_config_read(struct udevice *dev,
	65	int offset, void *buf, int size)
	66	{
	67	struct vexpress_config_sysreg *priv = dev_get_uclass_priv(dev);
	68
	69	if (size != sizeof(u32))
	70	return -EINVAL;
	71
	72	return vexpress_config_exec(priv, false, buf, size);
	73	}
	74
	75	static int vexpress_config_write(struct udevice *dev,
76	int offset, const void *buf, int size)
77	{
78	struct vexpress_config_sysreg *priv = dev_get_uclass_priv(dev);
79
80	if (size != sizeof(u32) * 2)
81	return -EINVAL;
82
83	return vexpress_config_exec(priv, true, (void *)buf, size);
84	}
85
86	static struct misc_ops vexpress_config_ops = {
87	.read = vexpress_config_read,
88	.write = vexpress_config_write,
89	};
90
91	static int vexpress_config_probe(struct udevice *dev)
92	{
93	struct ofnode_phandle_args args;
ffdb85bf	94	struct vexpress_config_sysreg *priv = dev_get_priv(dev);
0fabfeb2 LD	95	const char *prop;
	96	int err, prop_size;
	97
	98	err = dev_read_phandle_with_args(dev, "arm,vexpress,config-bridge",
	99	NULL, 0, 0, &args);
	100	if (err)
	101	return err;
	102
	103	prop = ofnode_get_property(args.node, "compatible", &prop_size);
	104	if (!prop \|\| (strncmp(prop, "arm,vexpress-sysreg", 19) != 0))
	105	return -ENOENT;
	106
0fabfeb2 LD	107	if (!priv)
	108	return -ENOMEM;
	109
0fabfeb2 LD	110	priv->addr = ofnode_get_addr(args.node);
	111
	112	return dev_read_u32(dev, "arm,vexpress,site", &priv->site);
	113	}
	114
	115	static const struct udevice_id vexpress_config_ids[] = {
	116	{ .compatible = "arm,vexpress,config-bus" },
	117	{ }
	118	};
	119
	120	U_BOOT_DRIVER(vexpress_config_drv) = {
	121	.name = "vexpress_config_bus",
	122	.id = UCLASS_MISC,
	123	.of_match = vexpress_config_ids,
	124	.bind = dm_scan_fdt_dev,
	125	.probe = vexpress_config_probe,
	126	.ops = &vexpress_config_ops,
ffdb85bf	127	.priv_auto = sizeof(struct vexpress_config_sysreg),
0fabfeb2	128	};