drivers/memory/bt1-l2-ctl.c - third_party/linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0-only
 /*
  * Copyright (C) 2020 BAIKAL ELECTRONICS, JSC
  *
  * Authors:
  *   Serge Semin <Sergey.Semin@baikalelectronics.ru>
  *
  * Baikal-T1 CM2 L2-cache Control Block driver.
  */

 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/bitfield.h>
 #include <linux/types.h>
 #include <linux/device.h>
 #include <linux/platform_device.h>
 #include <linux/regmap.h>
 #include <linux/mfd/syscon.h>
 #include <linux/sysfs.h>
 #include <linux/of.h>

 #define L2_CTL_REG			0x028
 #define L2_CTL_DATA_STALL_FLD		0
 #define L2_CTL_DATA_STALL_MASK		GENMASK(1, L2_CTL_DATA_STALL_FLD)
 #define L2_CTL_TAG_STALL_FLD		2
 #define L2_CTL_TAG_STALL_MASK		GENMASK(3, L2_CTL_TAG_STALL_FLD)
 #define L2_CTL_WS_STALL_FLD		4
 #define L2_CTL_WS_STALL_MASK		GENMASK(5, L2_CTL_WS_STALL_FLD)
 #define L2_CTL_SET_CLKRATIO		BIT(13)
 #define L2_CTL_CLKRATIO_LOCK		BIT(31)

 #define L2_CTL_STALL_MIN		0
 #define L2_CTL_STALL_MAX		3
 #define L2_CTL_STALL_SET_DELAY_US	1
 #define L2_CTL_STALL_SET_TOUT_US	1000

 /*
  * struct l2_ctl - Baikal-T1 L2 Control block private data.
  * @dev: Pointer to the device structure.
  * @sys_regs: Baikal-T1 System Controller registers map.
  */
 struct l2_ctl {
 	struct device *dev;

 	struct regmap *sys_regs;
 };

 /*
  * enum l2_ctl_stall - Baikal-T1 L2-cache-RAM stall identifier.
  * @L2_WSSTALL: Way-select latency.
  * @L2_TAGSTALL: Tag latency.
  * @L2_DATASTALL: Data latency.
  */
 enum l2_ctl_stall {
 	L2_WS_STALL,
 	L2_TAG_STALL,
 	L2_DATA_STALL
 };

 /*
  * struct l2_ctl_device_attribute - Baikal-T1 L2-cache device attribute.
  * @dev_attr: Actual sysfs device attribute.
  * @id: L2-cache stall field identifier.
  */
 struct l2_ctl_device_attribute {
 	struct device_attribute dev_attr;
 	enum l2_ctl_stall id;
 };

 #define to_l2_ctl_dev_attr(_dev_attr) \
 	container_of(_dev_attr, struct l2_ctl_device_attribute, dev_attr)

 #define L2_CTL_ATTR_RW(_name, _prefix, _id) \
 	struct l2_ctl_device_attribute l2_ctl_attr_##_name = \
 		{ __ATTR(_name, 0644, _prefix##_show, _prefix##_store),	_id }

 static int l2_ctl_get_latency(struct l2_ctl *l2, enum l2_ctl_stall id, u32 *val)
 {
 	u32 data = 0;
 	int ret;

 	ret = regmap_read(l2->sys_regs, L2_CTL_REG, &data);
 	if (ret)
 		return ret;

 	switch (id) {
 	case L2_WS_STALL:
 		*val = FIELD_GET(L2_CTL_WS_STALL_MASK, data);
 		break;
 	case L2_TAG_STALL:
 		*val = FIELD_GET(L2_CTL_TAG_STALL_MASK, data);
 		break;
 	case L2_DATA_STALL:
 		*val = FIELD_GET(L2_CTL_DATA_STALL_MASK, data);
 		break;
 	default:
 		return -EINVAL;
 	}

 	return 0;
 }

 static int l2_ctl_set_latency(struct l2_ctl *l2, enum l2_ctl_stall id, u32 val)
 {
 	u32 mask = 0, data = 0;
 	int ret;

 	val = clamp_val(val, L2_CTL_STALL_MIN, L2_CTL_STALL_MAX);

 	switch (id) {
 	case L2_WS_STALL:
 		data = FIELD_PREP(L2_CTL_WS_STALL_MASK, val);
 		mask = L2_CTL_WS_STALL_MASK;
 		break;
 	case L2_TAG_STALL:
 		data = FIELD_PREP(L2_CTL_TAG_STALL_MASK, val);
 		mask = L2_CTL_TAG_STALL_MASK;
 		break;
 	case L2_DATA_STALL:
 		data = FIELD_PREP(L2_CTL_DATA_STALL_MASK, val);
 		mask = L2_CTL_DATA_STALL_MASK;
 		break;
 	default:
 		return -EINVAL;
 	}

 	data |= L2_CTL_SET_CLKRATIO;
 	mask |= L2_CTL_SET_CLKRATIO;

 	ret = regmap_update_bits(l2->sys_regs, L2_CTL_REG, mask, data);
 	if (ret)
 		return ret;

 	return regmap_read_poll_timeout(l2->sys_regs, L2_CTL_REG, data,
 					data & L2_CTL_CLKRATIO_LOCK,
 					L2_CTL_STALL_SET_DELAY_US,
 					L2_CTL_STALL_SET_TOUT_US);
 }

 static void l2_ctl_clear_data(void *data)
 {
 	struct l2_ctl *l2 = data;
 	struct platform_device *pdev = to_platform_device(l2->dev);

 	platform_set_drvdata(pdev, NULL);
 }

 static struct l2_ctl *l2_ctl_create_data(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
 	struct l2_ctl *l2;
 	int ret;

 	l2 = devm_kzalloc(dev, sizeof(*l2), GFP_KERNEL);
 	if (!l2)
 		return ERR_PTR(-ENOMEM);

 	ret = devm_add_action(dev, l2_ctl_clear_data, l2);
 	if (ret) {
 		dev_err(dev, "Can't add L2 CTL data clear action\n");
 		return ERR_PTR(ret);
 	}

 	l2->dev = dev;
 	platform_set_drvdata(pdev, l2);

 	return l2;
 }

 static int l2_ctl_find_sys_regs(struct l2_ctl *l2)
 {
 	l2->sys_regs = syscon_node_to_regmap(l2->dev->of_node->parent);
 	if (IS_ERR(l2->sys_regs)) {
 		dev_err(l2->dev, "Couldn't get L2 CTL register map\n");
 		return PTR_ERR(l2->sys_regs);
 	}

 	return 0;
 }

 static int l2_ctl_of_parse_property(struct l2_ctl *l2, enum l2_ctl_stall id,
 				    const char *propname)
 {
 	int ret = 0;
 	u32 data;

 	if (!of_property_read_u32(l2->dev->of_node, propname, &data)) {
 		ret = l2_ctl_set_latency(l2, id, data);
 		if (ret)
 			dev_err(l2->dev, "Invalid value of '%s'\n", propname);
 	}

 	return ret;
 }

 static int l2_ctl_of_parse(struct l2_ctl *l2)
 {
 	int ret;

 	ret = l2_ctl_of_parse_property(l2, L2_WS_STALL, "baikal,l2-ws-latency");
 	if (ret)
 		return ret;

 	ret = l2_ctl_of_parse_property(l2, L2_TAG_STALL, "baikal,l2-tag-latency");
 	if (ret)
 		return ret;

 	return l2_ctl_of_parse_property(l2, L2_DATA_STALL,
 					"baikal,l2-data-latency");
 }

 static ssize_t l2_ctl_latency_show(struct device *dev,
 				   struct device_attribute *attr,
 				   char *buf)
 {
 	struct l2_ctl_device_attribute *devattr = to_l2_ctl_dev_attr(attr);
 	struct l2_ctl *l2 = dev_get_drvdata(dev);
 	u32 data;
 	int ret;

 	ret = l2_ctl_get_latency(l2, devattr->id, &data);
 	if (ret)
 		return ret;

 	return scnprintf(buf, PAGE_SIZE, "%u\n", data);
 }

 static ssize_t l2_ctl_latency_store(struct device *dev,
 				    struct device_attribute *attr,
 				    const char *buf, size_t count)
 {
 	struct l2_ctl_device_attribute *devattr = to_l2_ctl_dev_attr(attr);
 	struct l2_ctl *l2 = dev_get_drvdata(dev);
 	u32 data;
 	int ret;

 	if (kstrtouint(buf, 0, &data) < 0)
 		return -EINVAL;

 	ret = l2_ctl_set_latency(l2, devattr->id, data);
 	if (ret)
 		return ret;

 	return count;
 }

 static L2_CTL_ATTR_RW(l2_ws_latency, l2_ctl_latency, L2_WS_STALL);
 static L2_CTL_ATTR_RW(l2_tag_latency, l2_ctl_latency, L2_TAG_STALL);
 static L2_CTL_ATTR_RW(l2_data_latency, l2_ctl_latency, L2_DATA_STALL);

 static struct attribute *l2_ctl_sysfs_attrs[] = {
 	&l2_ctl_attr_l2_ws_latency.dev_attr.attr,
 	&l2_ctl_attr_l2_tag_latency.dev_attr.attr,
 	&l2_ctl_attr_l2_data_latency.dev_attr.attr,
 	NULL
 };
 ATTRIBUTE_GROUPS(l2_ctl_sysfs);

 static void l2_ctl_remove_sysfs(void *data)
 {
 	struct l2_ctl *l2 = data;

 	device_remove_groups(l2->dev, l2_ctl_sysfs_groups);
 }

 static int l2_ctl_init_sysfs(struct l2_ctl *l2)
 {
 	int ret;

 	ret = device_add_groups(l2->dev, l2_ctl_sysfs_groups);
 	if (ret) {
 		dev_err(l2->dev, "Failed to create L2 CTL sysfs nodes\n");
 		return ret;
 	}

 	ret = devm_add_action_or_reset(l2->dev, l2_ctl_remove_sysfs, l2);
 	if (ret)
 		dev_err(l2->dev, "Can't add L2 CTL sysfs remove action\n");

 	return ret;
 }

 static int l2_ctl_probe(struct platform_device *pdev)
 {
 	struct l2_ctl *l2;
 	int ret;

 	l2 = l2_ctl_create_data(pdev);
 	if (IS_ERR(l2))
 		return PTR_ERR(l2);

 	ret = l2_ctl_find_sys_regs(l2);
 	if (ret)
 		return ret;

 	ret = l2_ctl_of_parse(l2);
 	if (ret)
 		return ret;

 	ret = l2_ctl_init_sysfs(l2);
 	if (ret)
 		return ret;

 	return 0;
 }

 static const struct of_device_id l2_ctl_of_match[] = {
 	{ .compatible = "baikal,bt1-l2-ctl" },
 	{ }
 };
 MODULE_DEVICE_TABLE(of, l2_ctl_of_match);

 static struct platform_driver l2_ctl_driver = {
 	.probe = l2_ctl_probe,
 	.driver = {
 		.name = "bt1-l2-ctl",
 		.of_match_table = l2_ctl_of_match
 	}
 };
 module_platform_driver(l2_ctl_driver);

 MODULE_AUTHOR("Serge Semin <Sergey.Semin@baikalelectronics.ru>");
 MODULE_DESCRIPTION("Baikal-T1 L2-cache driver");
 MODULE_LICENSE("GPL v2");
	// SPDX-License-Identifier: GPL-2.0-only
	/*
	* Copyright (C) 2020 BAIKAL ELECTRONICS, JSC
	*
	* Authors:
	* Serge Semin <Sergey.Semin@baikalelectronics.ru>
	*
	* Baikal-T1 CM2 L2-cache Control Block driver.
	*/

	#include <linux/kernel.h>
	#include <linux/module.h>
	#include <linux/bitfield.h>
	#include <linux/types.h>
	#include <linux/device.h>
	#include <linux/platform_device.h>
	#include <linux/regmap.h>
	#include <linux/mfd/syscon.h>
	#include <linux/sysfs.h>
	#include <linux/of.h>

	#define L2_CTL_REG 0x028
	#define L2_CTL_DATA_STALL_FLD 0
	#define L2_CTL_DATA_STALL_MASK GENMASK(1, L2_CTL_DATA_STALL_FLD)
	#define L2_CTL_TAG_STALL_FLD 2
	#define L2_CTL_TAG_STALL_MASK GENMASK(3, L2_CTL_TAG_STALL_FLD)
	#define L2_CTL_WS_STALL_FLD 4
	#define L2_CTL_WS_STALL_MASK GENMASK(5, L2_CTL_WS_STALL_FLD)
	#define L2_CTL_SET_CLKRATIO BIT(13)
	#define L2_CTL_CLKRATIO_LOCK BIT(31)

	#define L2_CTL_STALL_MIN 0
	#define L2_CTL_STALL_MAX 3
	#define L2_CTL_STALL_SET_DELAY_US 1
	#define L2_CTL_STALL_SET_TOUT_US 1000

	/*
	* struct l2_ctl - Baikal-T1 L2 Control block private data.
	* @dev: Pointer to the device structure.
	* @sys_regs: Baikal-T1 System Controller registers map.
	*/
	struct l2_ctl {
	struct device *dev;

	struct regmap *sys_regs;
	};

	/*
	* enum l2_ctl_stall - Baikal-T1 L2-cache-RAM stall identifier.
	* @L2_WSSTALL: Way-select latency.
	* @L2_TAGSTALL: Tag latency.
	* @L2_DATASTALL: Data latency.
	*/
	enum l2_ctl_stall {
	L2_WS_STALL,
	L2_TAG_STALL,
	L2_DATA_STALL
	};

	/*
	* struct l2_ctl_device_attribute - Baikal-T1 L2-cache device attribute.
	* @dev_attr: Actual sysfs device attribute.
	* @id: L2-cache stall field identifier.
	*/
	struct l2_ctl_device_attribute {
	struct device_attribute dev_attr;
	enum l2_ctl_stall id;
	};

	#define to_l2_ctl_dev_attr(_dev_attr) \
	container_of(_dev_attr, struct l2_ctl_device_attribute, dev_attr)

	#define L2_CTL_ATTR_RW(_name, _prefix, _id) \
	struct l2_ctl_device_attribute l2_ctl_attr_##_name = \
	{ __ATTR(_name, 0644, _prefix##_show, _prefix##_store), _id }

	static int l2_ctl_get_latency(struct l2_ctl l2, enum l2_ctl_stall id, u32 val)
	{
	u32 data = 0;
	int ret;

	ret = regmap_read(l2->sys_regs, L2_CTL_REG, &data);
	if (ret)
	return ret;

	switch (id) {
	case L2_WS_STALL:
	*val = FIELD_GET(L2_CTL_WS_STALL_MASK, data);
	break;
	case L2_TAG_STALL:
	*val = FIELD_GET(L2_CTL_TAG_STALL_MASK, data);
	break;
	case L2_DATA_STALL:
	*val = FIELD_GET(L2_CTL_DATA_STALL_MASK, data);
	break;
	default:
	return -EINVAL;
	}

	return 0;
	}

	static int l2_ctl_set_latency(struct l2_ctl *l2, enum l2_ctl_stall id, u32 val)
	{
	u32 mask = 0, data = 0;
	int ret;

	val = clamp_val(val, L2_CTL_STALL_MIN, L2_CTL_STALL_MAX);

	switch (id) {
	case L2_WS_STALL:
	data = FIELD_PREP(L2_CTL_WS_STALL_MASK, val);
	mask = L2_CTL_WS_STALL_MASK;
	break;
	case L2_TAG_STALL:
	data = FIELD_PREP(L2_CTL_TAG_STALL_MASK, val);
	mask = L2_CTL_TAG_STALL_MASK;
	break;
	case L2_DATA_STALL:
	data = FIELD_PREP(L2_CTL_DATA_STALL_MASK, val);
	mask = L2_CTL_DATA_STALL_MASK;
	break;
	default:
	return -EINVAL;
	}

	data \|= L2_CTL_SET_CLKRATIO;
	mask \|= L2_CTL_SET_CLKRATIO;

	ret = regmap_update_bits(l2->sys_regs, L2_CTL_REG, mask, data);
	if (ret)
	return ret;

	return regmap_read_poll_timeout(l2->sys_regs, L2_CTL_REG, data,
	data & L2_CTL_CLKRATIO_LOCK,
	L2_CTL_STALL_SET_DELAY_US,
	L2_CTL_STALL_SET_TOUT_US);
	}

	static void l2_ctl_clear_data(void *data)
	{
	struct l2_ctl *l2 = data;
	struct platform_device *pdev = to_platform_device(l2->dev);

	platform_set_drvdata(pdev, NULL);
	}

	static struct l2_ctl l2_ctl_create_data(struct platform_device pdev)
	{
	struct device *dev = &pdev->dev;
	struct l2_ctl *l2;
	int ret;

	l2 = devm_kzalloc(dev, sizeof(*l2), GFP_KERNEL);
	if (!l2)
	return ERR_PTR(-ENOMEM);

	ret = devm_add_action(dev, l2_ctl_clear_data, l2);
	if (ret) {
	dev_err(dev, "Can't add L2 CTL data clear action\n");
	return ERR_PTR(ret);
	}

	l2->dev = dev;
	platform_set_drvdata(pdev, l2);

	return l2;
	}

	static int l2_ctl_find_sys_regs(struct l2_ctl *l2)
	{
	l2->sys_regs = syscon_node_to_regmap(l2->dev->of_node->parent);
	if (IS_ERR(l2->sys_regs)) {
	dev_err(l2->dev, "Couldn't get L2 CTL register map\n");
	return PTR_ERR(l2->sys_regs);
	}

	return 0;
	}

	static int l2_ctl_of_parse_property(struct l2_ctl *l2, enum l2_ctl_stall id,
	const char *propname)
	{
	int ret = 0;
	u32 data;

	if (!of_property_read_u32(l2->dev->of_node, propname, &data)) {
	ret = l2_ctl_set_latency(l2, id, data);
	if (ret)
	dev_err(l2->dev, "Invalid value of '%s'\n", propname);
	}

	return ret;
	}

	static int l2_ctl_of_parse(struct l2_ctl *l2)
	{
	int ret;

	ret = l2_ctl_of_parse_property(l2, L2_WS_STALL, "baikal,l2-ws-latency");
	if (ret)
	return ret;

	ret = l2_ctl_of_parse_property(l2, L2_TAG_STALL, "baikal,l2-tag-latency");
	if (ret)
	return ret;

	return l2_ctl_of_parse_property(l2, L2_DATA_STALL,
	"baikal,l2-data-latency");
	}

	static ssize_t l2_ctl_latency_show(struct device *dev,
	struct device_attribute *attr,
	char *buf)
	{
	struct l2_ctl_device_attribute *devattr = to_l2_ctl_dev_attr(attr);
	struct l2_ctl *l2 = dev_get_drvdata(dev);
	u32 data;
	int ret;

	ret = l2_ctl_get_latency(l2, devattr->id, &data);
	if (ret)
	return ret;

	return scnprintf(buf, PAGE_SIZE, "%u\n", data);
	}

	static ssize_t l2_ctl_latency_store(struct device *dev,
	struct device_attribute *attr,
	const char *buf, size_t count)
	{
	struct l2_ctl_device_attribute *devattr = to_l2_ctl_dev_attr(attr);
	struct l2_ctl *l2 = dev_get_drvdata(dev);
	u32 data;
	int ret;

	if (kstrtouint(buf, 0, &data) < 0)
	return -EINVAL;

	ret = l2_ctl_set_latency(l2, devattr->id, data);
	if (ret)
	return ret;

	return count;
	}

	static L2_CTL_ATTR_RW(l2_ws_latency, l2_ctl_latency, L2_WS_STALL);
	static L2_CTL_ATTR_RW(l2_tag_latency, l2_ctl_latency, L2_TAG_STALL);
	static L2_CTL_ATTR_RW(l2_data_latency, l2_ctl_latency, L2_DATA_STALL);

	static struct attribute *l2_ctl_sysfs_attrs[] = {
	&l2_ctl_attr_l2_ws_latency.dev_attr.attr,
	&l2_ctl_attr_l2_tag_latency.dev_attr.attr,
	&l2_ctl_attr_l2_data_latency.dev_attr.attr,
	NULL
	};
	ATTRIBUTE_GROUPS(l2_ctl_sysfs);

	static void l2_ctl_remove_sysfs(void *data)
	{
	struct l2_ctl *l2 = data;

	device_remove_groups(l2->dev, l2_ctl_sysfs_groups);
	}

	static int l2_ctl_init_sysfs(struct l2_ctl *l2)
	{
	int ret;

	ret = device_add_groups(l2->dev, l2_ctl_sysfs_groups);
	if (ret) {
	dev_err(l2->dev, "Failed to create L2 CTL sysfs nodes\n");
	return ret;
	}

	ret = devm_add_action_or_reset(l2->dev, l2_ctl_remove_sysfs, l2);
	if (ret)
	dev_err(l2->dev, "Can't add L2 CTL sysfs remove action\n");

	return ret;
	}

	static int l2_ctl_probe(struct platform_device *pdev)
	{
	struct l2_ctl *l2;
	int ret;

	l2 = l2_ctl_create_data(pdev);
	if (IS_ERR(l2))
	return PTR_ERR(l2);

	ret = l2_ctl_find_sys_regs(l2);
	if (ret)
	return ret;

	ret = l2_ctl_of_parse(l2);
	if (ret)
	return ret;

	ret = l2_ctl_init_sysfs(l2);
	if (ret)
	return ret;

	return 0;
	}

	static const struct of_device_id l2_ctl_of_match[] = {
	{ .compatible = "baikal,bt1-l2-ctl" },
	{ }
	};
	MODULE_DEVICE_TABLE(of, l2_ctl_of_match);

	static struct platform_driver l2_ctl_driver = {
	.probe = l2_ctl_probe,
	.driver = {
	.name = "bt1-l2-ctl",
	.of_match_table = l2_ctl_of_match
	}
	};
	module_platform_driver(l2_ctl_driver);

	MODULE_AUTHOR("Serge Semin <Sergey.Semin@baikalelectronics.ru>");
	MODULE_DESCRIPTION("Baikal-T1 L2-cache driver");
	MODULE_LICENSE("GPL v2");