diff options
Diffstat (limited to 'drivers/memory/dfl-emif.c')
| -rw-r--r-- | drivers/memory/dfl-emif.c | 207 |
1 files changed, 207 insertions, 0 deletions
diff --git a/drivers/memory/dfl-emif.c b/drivers/memory/dfl-emif.c new file mode 100644 index 000000000000..3f719816771d --- /dev/null +++ b/drivers/memory/dfl-emif.c @@ -0,0 +1,207 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * DFL device driver for EMIF private feature + * + * Copyright (C) 2020 Intel Corporation, Inc. + * + */ +#include <linux/bitfield.h> +#include <linux/dfl.h> +#include <linux/errno.h> +#include <linux/io.h> +#include <linux/iopoll.h> +#include <linux/io-64-nonatomic-lo-hi.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/spinlock.h> +#include <linux/types.h> + +#define FME_FEATURE_ID_EMIF 0x9 + +#define EMIF_STAT 0x8 +#define EMIF_STAT_INIT_DONE_SFT 0 +#define EMIF_STAT_CALC_FAIL_SFT 8 +#define EMIF_STAT_CLEAR_BUSY_SFT 16 +#define EMIF_CTRL 0x10 +#define EMIF_CTRL_CLEAR_EN_SFT 0 +#define EMIF_CTRL_CLEAR_EN_MSK GENMASK_ULL(3, 0) + +#define EMIF_POLL_INVL 10000 /* us */ +#define EMIF_POLL_TIMEOUT 5000000 /* us */ + +struct dfl_emif { + struct device *dev; + void __iomem *base; + spinlock_t lock; /* Serialises access to EMIF_CTRL reg */ +}; + +struct emif_attr { + struct device_attribute attr; + u32 shift; + u32 index; +}; + +#define to_emif_attr(dev_attr) \ + container_of(dev_attr, struct emif_attr, attr) + +static ssize_t emif_state_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct emif_attr *eattr = to_emif_attr(attr); + struct dfl_emif *de = dev_get_drvdata(dev); + u64 val; + + val = readq(de->base + EMIF_STAT); + + return sysfs_emit(buf, "%u\n", + !!(val & BIT_ULL(eattr->shift + eattr->index))); +} + +static ssize_t emif_clear_store(struct device *dev, + struct device_attribute *attr, + const char *buf, size_t count) +{ + struct emif_attr *eattr = to_emif_attr(attr); + struct dfl_emif *de = dev_get_drvdata(dev); + u64 clear_busy_msk, clear_en_msk, val; + void __iomem *base = de->base; + + if (!sysfs_streq(buf, "1")) + return -EINVAL; + + clear_busy_msk = BIT_ULL(EMIF_STAT_CLEAR_BUSY_SFT + eattr->index); + clear_en_msk = BIT_ULL(EMIF_CTRL_CLEAR_EN_SFT + eattr->index); + + spin_lock(&de->lock); + /* The CLEAR_EN field is WO, but other fields are RW */ + val = readq(base + EMIF_CTRL); + val &= ~EMIF_CTRL_CLEAR_EN_MSK; + val |= clear_en_msk; + writeq(val, base + EMIF_CTRL); + spin_unlock(&de->lock); + + if (readq_poll_timeout(base + EMIF_STAT, val, + !(val & clear_busy_msk), + EMIF_POLL_INVL, EMIF_POLL_TIMEOUT)) { + dev_err(de->dev, "timeout, fail to clear\n"); + return -ETIMEDOUT; + } + + return count; +} + +#define emif_state_attr(_name, _shift, _index) \ + static struct emif_attr emif_attr_##inf##_index##_##_name = \ + { .attr = __ATTR(inf##_index##_##_name, 0444, \ + emif_state_show, NULL), \ + .shift = (_shift), .index = (_index) } + +#define emif_clear_attr(_index) \ + static struct emif_attr emif_attr_##inf##_index##_clear = \ + { .attr = __ATTR(inf##_index##_clear, 0200, \ + NULL, emif_clear_store), \ + .index = (_index) } + +emif_state_attr(init_done, EMIF_STAT_INIT_DONE_SFT, 0); +emif_state_attr(init_done, EMIF_STAT_INIT_DONE_SFT, 1); +emif_state_attr(init_done, EMIF_STAT_INIT_DONE_SFT, 2); +emif_state_attr(init_done, EMIF_STAT_INIT_DONE_SFT, 3); + +emif_state_attr(cal_fail, EMIF_STAT_CALC_FAIL_SFT, 0); +emif_state_attr(cal_fail, EMIF_STAT_CALC_FAIL_SFT, 1); +emif_state_attr(cal_fail, EMIF_STAT_CALC_FAIL_SFT, 2); +emif_state_attr(cal_fail, EMIF_STAT_CALC_FAIL_SFT, 3); + +emif_clear_attr(0); +emif_clear_attr(1); +emif_clear_attr(2); +emif_clear_attr(3); + +static struct attribute *dfl_emif_attrs[] = { + &emif_attr_inf0_init_done.attr.attr, + &emif_attr_inf0_cal_fail.attr.attr, + &emif_attr_inf0_clear.attr.attr, + + &emif_attr_inf1_init_done.attr.attr, + &emif_attr_inf1_cal_fail.attr.attr, + &emif_attr_inf1_clear.attr.attr, + + &emif_attr_inf2_init_done.attr.attr, + &emif_attr_inf2_cal_fail.attr.attr, + &emif_attr_inf2_clear.attr.attr, + + &emif_attr_inf3_init_done.attr.attr, + &emif_attr_inf3_cal_fail.attr.attr, + &emif_attr_inf3_clear.attr.attr, + + NULL, +}; + +static umode_t dfl_emif_visible(struct kobject *kobj, + struct attribute *attr, int n) +{ + struct dfl_emif *de = dev_get_drvdata(kobj_to_dev(kobj)); + struct emif_attr *eattr = container_of(attr, struct emif_attr, + attr.attr); + u64 val; + + /* + * This device supports upto 4 memory interfaces, but not all + * interfaces are used on different platforms. The read out value of + * CLEAN_EN field (which is a bitmap) could tell how many interfaces + * are available. + */ + val = FIELD_GET(EMIF_CTRL_CLEAR_EN_MSK, readq(de->base + EMIF_CTRL)); + + return (val & BIT_ULL(eattr->index)) ? attr->mode : 0; +} + +static const struct attribute_group dfl_emif_group = { + .is_visible = dfl_emif_visible, + .attrs = dfl_emif_attrs, +}; + +static const struct attribute_group *dfl_emif_groups[] = { + &dfl_emif_group, + NULL, +}; + +static int dfl_emif_probe(struct dfl_device *ddev) +{ + struct device *dev = &ddev->dev; + struct dfl_emif *de; + + de = devm_kzalloc(dev, sizeof(*de), GFP_KERNEL); + if (!de) + return -ENOMEM; + + de->base = devm_ioremap_resource(dev, &ddev->mmio_res); + if (IS_ERR(de->base)) + return PTR_ERR(de->base); + + de->dev = dev; + spin_lock_init(&de->lock); + dev_set_drvdata(dev, de); + + return 0; +} + +static const struct dfl_device_id dfl_emif_ids[] = { + { FME_ID, FME_FEATURE_ID_EMIF }, + { } +}; +MODULE_DEVICE_TABLE(dfl, dfl_emif_ids); + +static struct dfl_driver dfl_emif_driver = { + .drv = { + .name = "dfl-emif", + .dev_groups = dfl_emif_groups, + }, + .id_table = dfl_emif_ids, + .probe = dfl_emif_probe, +}; +module_dfl_driver(dfl_emif_driver); + +MODULE_DESCRIPTION("DFL EMIF driver"); +MODULE_AUTHOR("Intel Corporation"); +MODULE_LICENSE("GPL v2"); |