// 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");