diff options
Diffstat (limited to 'drivers/soc/qcom/icc-bwmon.c')
| -rw-r--r-- | drivers/soc/qcom/icc-bwmon.c | 419 |
1 files changed, 419 insertions, 0 deletions
diff --git a/drivers/soc/qcom/icc-bwmon.c b/drivers/soc/qcom/icc-bwmon.c new file mode 100644 index 000000000000..7f8aca533cd3 --- /dev/null +++ b/drivers/soc/qcom/icc-bwmon.c @@ -0,0 +1,419 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (c) 2014-2018, The Linux Foundation. All rights reserved. + * Copyright (C) 2021-2022 Linaro Ltd + * Author: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>, based on + * previous work of Thara Gopinath and msm-4.9 downstream sources. + */ +#include <linux/interconnect.h> +#include <linux/interrupt.h> +#include <linux/io.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/of_device.h> +#include <linux/platform_device.h> +#include <linux/pm_opp.h> +#include <linux/sizes.h> + +/* + * The BWMON samples data throughput within 'sample_ms' time. With three + * configurable thresholds (Low, Medium and High) gives four windows (called + * zones) of current bandwidth: + * + * Zone 0: byte count < THRES_LO + * Zone 1: THRES_LO < byte count < THRES_MED + * Zone 2: THRES_MED < byte count < THRES_HIGH + * Zone 3: THRES_HIGH < byte count + * + * Zones 0 and 2 are not used by this driver. + */ + +/* Internal sampling clock frequency */ +#define HW_TIMER_HZ 19200000 + +#define BWMON_GLOBAL_IRQ_STATUS 0x0 +#define BWMON_GLOBAL_IRQ_CLEAR 0x8 +#define BWMON_GLOBAL_IRQ_ENABLE 0xc +#define BWMON_GLOBAL_IRQ_ENABLE_ENABLE BIT(0) + +#define BWMON_IRQ_STATUS 0x100 +#define BWMON_IRQ_STATUS_ZONE_SHIFT 4 +#define BWMON_IRQ_CLEAR 0x108 +#define BWMON_IRQ_ENABLE 0x10c +#define BWMON_IRQ_ENABLE_ZONE1_SHIFT 5 +#define BWMON_IRQ_ENABLE_ZONE2_SHIFT 6 +#define BWMON_IRQ_ENABLE_ZONE3_SHIFT 7 +#define BWMON_IRQ_ENABLE_MASK (BIT(BWMON_IRQ_ENABLE_ZONE1_SHIFT) | \ + BIT(BWMON_IRQ_ENABLE_ZONE3_SHIFT)) + +#define BWMON_ENABLE 0x2a0 +#define BWMON_ENABLE_ENABLE BIT(0) + +#define BWMON_CLEAR 0x2a4 +#define BWMON_CLEAR_CLEAR BIT(0) + +#define BWMON_SAMPLE_WINDOW 0x2a8 +#define BWMON_THRESHOLD_HIGH 0x2ac +#define BWMON_THRESHOLD_MED 0x2b0 +#define BWMON_THRESHOLD_LOW 0x2b4 + +#define BWMON_ZONE_ACTIONS 0x2b8 +/* + * Actions to perform on some zone 'z' when current zone hits the threshold: + * Increment counter of zone 'z' + */ +#define BWMON_ZONE_ACTIONS_INCREMENT(z) (0x2 << ((z) * 2)) +/* Clear counter of zone 'z' */ +#define BWMON_ZONE_ACTIONS_CLEAR(z) (0x1 << ((z) * 2)) + +/* Zone 0 threshold hit: Clear zone count */ +#define BWMON_ZONE_ACTIONS_ZONE0 (BWMON_ZONE_ACTIONS_CLEAR(0)) + +/* Zone 1 threshold hit: Increment zone count & clear lower zones */ +#define BWMON_ZONE_ACTIONS_ZONE1 (BWMON_ZONE_ACTIONS_INCREMENT(1) | \ + BWMON_ZONE_ACTIONS_CLEAR(0)) + +/* Zone 2 threshold hit: Increment zone count & clear lower zones */ +#define BWMON_ZONE_ACTIONS_ZONE2 (BWMON_ZONE_ACTIONS_INCREMENT(2) | \ + BWMON_ZONE_ACTIONS_CLEAR(1) | \ + BWMON_ZONE_ACTIONS_CLEAR(0)) + +/* Zone 3 threshold hit: Increment zone count & clear lower zones */ +#define BWMON_ZONE_ACTIONS_ZONE3 (BWMON_ZONE_ACTIONS_INCREMENT(3) | \ + BWMON_ZONE_ACTIONS_CLEAR(2) | \ + BWMON_ZONE_ACTIONS_CLEAR(1) | \ + BWMON_ZONE_ACTIONS_CLEAR(0)) +/* Value for BWMON_ZONE_ACTIONS */ +#define BWMON_ZONE_ACTIONS_DEFAULT (BWMON_ZONE_ACTIONS_ZONE0 | \ + BWMON_ZONE_ACTIONS_ZONE1 << 8 | \ + BWMON_ZONE_ACTIONS_ZONE2 << 16 | \ + BWMON_ZONE_ACTIONS_ZONE3 << 24) + +/* + * There is no clear documentation/explanation of BWMON_THRESHOLD_COUNT + * register. Based on observations, this is number of times one threshold has to + * be reached, to trigger interrupt in given zone. + * + * 0xff are maximum values meant to ignore the zones 0 and 2. + */ +#define BWMON_THRESHOLD_COUNT 0x2bc +#define BWMON_THRESHOLD_COUNT_ZONE1_SHIFT 8 +#define BWMON_THRESHOLD_COUNT_ZONE2_SHIFT 16 +#define BWMON_THRESHOLD_COUNT_ZONE3_SHIFT 24 +#define BWMON_THRESHOLD_COUNT_ZONE0_DEFAULT 0xff +#define BWMON_THRESHOLD_COUNT_ZONE2_DEFAULT 0xff + +/* BWMONv4 count registers use count unit of 64 kB */ +#define BWMON_COUNT_UNIT_KB 64 +#define BWMON_ZONE_COUNT 0x2d8 +#define BWMON_ZONE_MAX(zone) (0x2e0 + 4 * (zone)) + +struct icc_bwmon_data { + unsigned int sample_ms; + unsigned int default_highbw_kbps; + unsigned int default_medbw_kbps; + unsigned int default_lowbw_kbps; + u8 zone1_thres_count; + u8 zone3_thres_count; +}; + +struct icc_bwmon { + struct device *dev; + void __iomem *base; + int irq; + + unsigned int default_lowbw_kbps; + unsigned int sample_ms; + unsigned int max_bw_kbps; + unsigned int min_bw_kbps; + unsigned int target_kbps; + unsigned int current_kbps; +}; + +static void bwmon_clear_counters(struct icc_bwmon *bwmon) +{ + /* + * Clear counters. The order and barriers are + * important. Quoting downstream Qualcomm msm-4.9 tree: + * + * The counter clear and IRQ clear bits are not in the same 4KB + * region. So, we need to make sure the counter clear is completed + * before we try to clear the IRQ or do any other counter operations. + */ + writel(BWMON_CLEAR_CLEAR, bwmon->base + BWMON_CLEAR); +} + +static void bwmon_clear_irq(struct icc_bwmon *bwmon) +{ + /* + * Clear zone and global interrupts. The order and barriers are + * important. Quoting downstream Qualcomm msm-4.9 tree: + * + * Synchronize the local interrupt clear in mon_irq_clear() + * with the global interrupt clear here. Otherwise, the CPU + * may reorder the two writes and clear the global interrupt + * before the local interrupt, causing the global interrupt + * to be retriggered by the local interrupt still being high. + * + * Similarly, because the global registers are in a different + * region than the local registers, we need to ensure any register + * writes to enable the monitor after this call are ordered with the + * clearing here so that local writes don't happen before the + * interrupt is cleared. + */ + writel(BWMON_IRQ_ENABLE_MASK, bwmon->base + BWMON_IRQ_CLEAR); + writel(BIT(0), bwmon->base + BWMON_GLOBAL_IRQ_CLEAR); +} + +static void bwmon_disable(struct icc_bwmon *bwmon) +{ + /* Disable interrupts. Strict ordering, see bwmon_clear_irq(). */ + writel(0x0, bwmon->base + BWMON_GLOBAL_IRQ_ENABLE); + writel(0x0, bwmon->base + BWMON_IRQ_ENABLE); + + /* + * Disable bwmon. Must happen before bwmon_clear_irq() to avoid spurious + * IRQ. + */ + writel(0x0, bwmon->base + BWMON_ENABLE); +} + +static void bwmon_enable(struct icc_bwmon *bwmon, unsigned int irq_enable) +{ + /* Enable interrupts */ + writel(BWMON_GLOBAL_IRQ_ENABLE_ENABLE, + bwmon->base + BWMON_GLOBAL_IRQ_ENABLE); + writel(irq_enable, bwmon->base + BWMON_IRQ_ENABLE); + + /* Enable bwmon */ + writel(BWMON_ENABLE_ENABLE, bwmon->base + BWMON_ENABLE); +} + +static unsigned int bwmon_kbps_to_count(unsigned int kbps) +{ + return kbps / BWMON_COUNT_UNIT_KB; +} + +static void bwmon_set_threshold(struct icc_bwmon *bwmon, unsigned int reg, + unsigned int kbps) +{ + unsigned int thres; + + thres = mult_frac(bwmon_kbps_to_count(kbps), bwmon->sample_ms, + MSEC_PER_SEC); + writel_relaxed(thres, bwmon->base + reg); +} + +static void bwmon_start(struct icc_bwmon *bwmon, + const struct icc_bwmon_data *data) +{ + unsigned int thres_count; + int window; + + bwmon_clear_counters(bwmon); + + window = mult_frac(bwmon->sample_ms, HW_TIMER_HZ, MSEC_PER_SEC); + /* Maximum sampling window: 0xfffff */ + writel_relaxed(window, bwmon->base + BWMON_SAMPLE_WINDOW); + + bwmon_set_threshold(bwmon, BWMON_THRESHOLD_HIGH, + data->default_highbw_kbps); + bwmon_set_threshold(bwmon, BWMON_THRESHOLD_MED, + data->default_medbw_kbps); + bwmon_set_threshold(bwmon, BWMON_THRESHOLD_LOW, + data->default_lowbw_kbps); + + thres_count = data->zone3_thres_count << BWMON_THRESHOLD_COUNT_ZONE3_SHIFT | + BWMON_THRESHOLD_COUNT_ZONE2_DEFAULT << BWMON_THRESHOLD_COUNT_ZONE2_SHIFT | + data->zone1_thres_count << BWMON_THRESHOLD_COUNT_ZONE1_SHIFT | + BWMON_THRESHOLD_COUNT_ZONE0_DEFAULT; + writel_relaxed(thres_count, bwmon->base + BWMON_THRESHOLD_COUNT); + writel_relaxed(BWMON_ZONE_ACTIONS_DEFAULT, + bwmon->base + BWMON_ZONE_ACTIONS); + /* Write barriers in bwmon_clear_irq() */ + + bwmon_clear_irq(bwmon); + bwmon_enable(bwmon, BWMON_IRQ_ENABLE_MASK); +} + +static irqreturn_t bwmon_intr(int irq, void *dev_id) +{ + struct icc_bwmon *bwmon = dev_id; + unsigned int status, max; + int zone; + + status = readl(bwmon->base + BWMON_IRQ_STATUS); + status &= BWMON_IRQ_ENABLE_MASK; + if (!status) { + /* + * Only zone 1 and zone 3 interrupts are enabled but zone 2 + * threshold could be hit and trigger interrupt even if not + * enabled. + * Such spurious interrupt might come with valuable max count or + * not, so solution would be to always check all + * BWMON_ZONE_MAX() registers to find the highest value. + * Such case is currently ignored. + */ + return IRQ_NONE; + } + + bwmon_disable(bwmon); + + zone = get_bitmask_order(status >> BWMON_IRQ_STATUS_ZONE_SHIFT) - 1; + /* + * Zone max bytes count register returns count units within sampling + * window. Downstream kernel for BWMONv4 (called BWMON type 2 in + * downstream) always increments the max bytes count by one. + */ + max = readl(bwmon->base + BWMON_ZONE_MAX(zone)) + 1; + max *= BWMON_COUNT_UNIT_KB; + bwmon->target_kbps = mult_frac(max, MSEC_PER_SEC, bwmon->sample_ms); + + return IRQ_WAKE_THREAD; +} + +static irqreturn_t bwmon_intr_thread(int irq, void *dev_id) +{ + struct icc_bwmon *bwmon = dev_id; + unsigned int irq_enable = 0; + struct dev_pm_opp *opp, *target_opp; + unsigned int bw_kbps, up_kbps, down_kbps; + + bw_kbps = bwmon->target_kbps; + + target_opp = dev_pm_opp_find_bw_ceil(bwmon->dev, &bw_kbps, 0); + if (IS_ERR(target_opp) && PTR_ERR(target_opp) == -ERANGE) + target_opp = dev_pm_opp_find_bw_floor(bwmon->dev, &bw_kbps, 0); + + bwmon->target_kbps = bw_kbps; + + bw_kbps--; + opp = dev_pm_opp_find_bw_floor(bwmon->dev, &bw_kbps, 0); + if (IS_ERR(opp) && PTR_ERR(opp) == -ERANGE) + down_kbps = bwmon->target_kbps; + else + down_kbps = bw_kbps; + + up_kbps = bwmon->target_kbps + 1; + + if (bwmon->target_kbps >= bwmon->max_bw_kbps) + irq_enable = BIT(BWMON_IRQ_ENABLE_ZONE1_SHIFT); + else if (bwmon->target_kbps <= bwmon->min_bw_kbps) + irq_enable = BIT(BWMON_IRQ_ENABLE_ZONE3_SHIFT); + else + irq_enable = BWMON_IRQ_ENABLE_MASK; + + bwmon_set_threshold(bwmon, BWMON_THRESHOLD_HIGH, up_kbps); + bwmon_set_threshold(bwmon, BWMON_THRESHOLD_MED, down_kbps); + /* Write barriers in bwmon_clear_counters() */ + bwmon_clear_counters(bwmon); + bwmon_clear_irq(bwmon); + bwmon_enable(bwmon, irq_enable); + + if (bwmon->target_kbps == bwmon->current_kbps) + goto out; + + dev_pm_opp_set_opp(bwmon->dev, target_opp); + bwmon->current_kbps = bwmon->target_kbps; + +out: + dev_pm_opp_put(target_opp); + if (!IS_ERR(opp)) + dev_pm_opp_put(opp); + + return IRQ_HANDLED; +} + +static int bwmon_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct dev_pm_opp *opp; + struct icc_bwmon *bwmon; + const struct icc_bwmon_data *data; + int ret; + + bwmon = devm_kzalloc(dev, sizeof(*bwmon), GFP_KERNEL); + if (!bwmon) + return -ENOMEM; + + data = of_device_get_match_data(dev); + + bwmon->base = devm_platform_ioremap_resource(pdev, 0); + if (IS_ERR(bwmon->base)) { + dev_err(dev, "failed to map bwmon registers\n"); + return PTR_ERR(bwmon->base); + } + + bwmon->irq = platform_get_irq(pdev, 0); + if (bwmon->irq < 0) + return bwmon->irq; + + ret = devm_pm_opp_of_add_table(dev); + if (ret) + return dev_err_probe(dev, ret, "failed to add OPP table\n"); + + bwmon->max_bw_kbps = UINT_MAX; + opp = dev_pm_opp_find_bw_floor(dev, &bwmon->max_bw_kbps, 0); + if (IS_ERR(opp)) + return dev_err_probe(dev, ret, "failed to find max peak bandwidth\n"); + + bwmon->min_bw_kbps = 0; + opp = dev_pm_opp_find_bw_ceil(dev, &bwmon->min_bw_kbps, 0); + if (IS_ERR(opp)) + return dev_err_probe(dev, ret, "failed to find min peak bandwidth\n"); + + bwmon->sample_ms = data->sample_ms; + bwmon->default_lowbw_kbps = data->default_lowbw_kbps; + bwmon->dev = dev; + + bwmon_disable(bwmon); + ret = devm_request_threaded_irq(dev, bwmon->irq, bwmon_intr, + bwmon_intr_thread, + IRQF_ONESHOT, dev_name(dev), bwmon); + if (ret) + return dev_err_probe(dev, ret, "failed to request IRQ\n"); + + platform_set_drvdata(pdev, bwmon); + bwmon_start(bwmon, data); + + return 0; +} + +static int bwmon_remove(struct platform_device *pdev) +{ + struct icc_bwmon *bwmon = platform_get_drvdata(pdev); + + bwmon_disable(bwmon); + + return 0; +} + +/* BWMON v4 */ +static const struct icc_bwmon_data msm8998_bwmon_data = { + .sample_ms = 4, + .default_highbw_kbps = 4800 * 1024, /* 4.8 GBps */ + .default_medbw_kbps = 512 * 1024, /* 512 MBps */ + .default_lowbw_kbps = 0, + .zone1_thres_count = 16, + .zone3_thres_count = 1, +}; + +static const struct of_device_id bwmon_of_match[] = { + { .compatible = "qcom,msm8998-bwmon", .data = &msm8998_bwmon_data }, + {} +}; +MODULE_DEVICE_TABLE(of, bwmon_of_match); + +static struct platform_driver bwmon_driver = { + .probe = bwmon_probe, + .remove = bwmon_remove, + .driver = { + .name = "qcom-bwmon", + .of_match_table = bwmon_of_match, + }, +}; +module_platform_driver(bwmon_driver); + +MODULE_AUTHOR("Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>"); +MODULE_DESCRIPTION("QCOM BWMON driver"); +MODULE_LICENSE("GPL"); |