@@ -8,6 +8,7 @@
#include <linux/debugfs.h>
#include <linux/gpio/driver.h>
#include <linux/module.h>
+#include <linux/mutex.h>
#include <linux/platform_device.h>
#include <uapi/linux/gpio.h>
@@ -33,6 +34,9 @@
#define TGPIOCTL_PM BIT(4)
#define DRIVER_NAME "intel-pmc-tio"
+#define GPIO_COUNT 1
+#define INPUT_SNAPSHOT_FREQ 8
+#define INPUT_SNAPSHOT_COUNT 3
struct intel_pmc_tio_chip {
struct gpio_chip gch;
@@ -40,8 +44,29 @@ struct intel_pmc_tio_chip {
struct dentry *root;
struct debugfs_regset32 *regset;
void __iomem *base;
+ struct mutex lock; /* Protects 'ctrl', time */
+ struct delayed_work input_work;
+ bool input_work_running;
+ bool systime_valid;
+ unsigned int systime_index;
+ struct system_time_snapshot systime_snapshot[INPUT_SNAPSHOT_COUNT];
+ u64 last_event_count;
+ u64 last_art_timestamp;
};
+struct intel_pmc_tio_get_time_arg {
+ struct intel_pmc_tio_chip *tio;
+ u32 eflags;
+ u32 event_id;
+ u64 abs_event_count;
+};
+
+#define gch_to_intel_pmc_tio(i) \
+ (container_of((i), struct intel_pmc_tio_chip, gch))
+
+#define inws_to_intel_pmc_tio(i) \
+ (container_of((i), struct intel_pmc_tio_chip, input_work.work))
+
static const struct debugfs_reg32 intel_pmc_tio_regs[] = {
{
.name = "TGPIOCTL",
@@ -81,6 +106,193 @@ static const struct debugfs_reg32 intel_pmc_tio_regs[] = {
},
};
+static inline u32 intel_pmc_tio_readl(struct intel_pmc_tio_chip *tio,
+ u32 offset)
+{
+ return readl(tio->base + offset);
+}
+
+static inline void intel_pmc_tio_writel(struct intel_pmc_tio_chip *tio,
+ u32 offset, u32 value)
+{
+ writel(value, tio->base + offset);
+}
+
+#define INTEL_PMC_TIO_RD_REG(offset)( \
+ intel_pmc_tio_readl((tio), (offset)))
+#define INTEL_PMC_TIO_WR_REG(offset, value)( \
+ intel_pmc_tio_writel((tio), (offset), (value)))
+
+static void intel_pmc_tio_enable_input(struct intel_pmc_tio_chip *tio,
+ u32 eflags)
+{
+ bool rising, falling;
+ u32 ctrl;
+
+ /* Disable */
+ ctrl = INTEL_PMC_TIO_RD_REG(TGPIOCTL);
+ ctrl &= ~TGPIOCTL_EN;
+ INTEL_PMC_TIO_WR_REG(TGPIOCTL, ctrl);
+
+ tio->last_event_count = 0;
+
+ /* Configure Input */
+ ctrl |= TGPIOCTL_DIR;
+ ctrl &= ~TGPIOCTL_EP;
+
+ rising = eflags & GPIO_V2_LINE_FLAG_EDGE_RISING;
+ falling = eflags & GPIO_V2_LINE_FLAG_EDGE_FALLING;
+ if (rising && falling)
+ ctrl |= TGPIOCTL_EP_TOGGLE_EDGE;
+ else if (rising)
+ ctrl |= TGPIOCTL_EP_RISING_EDGE;
+ else
+ ctrl |= TGPIOCTL_EP_FALLING_EDGE;
+
+ /* Enable */
+ INTEL_PMC_TIO_WR_REG(TGPIOCTL, ctrl);
+ ctrl |= TGPIOCTL_EN;
+ INTEL_PMC_TIO_WR_REG(TGPIOCTL, ctrl);
+}
+
+static void intel_pmc_tio_input_work(struct work_struct *input_work)
+{
+ struct intel_pmc_tio_chip *tio = inws_to_intel_pmc_tio(input_work);
+
+ mutex_lock(&tio->lock);
+
+ tio->systime_index = (tio->systime_index + 1) % INPUT_SNAPSHOT_COUNT;
+ if (tio->systime_index == INPUT_SNAPSHOT_COUNT - 1)
+ tio->systime_valid = true;
+ ktime_get_snapshot(&tio->systime_snapshot[tio->systime_index]);
+ schedule_delayed_work(&tio->input_work, HZ / INPUT_SNAPSHOT_FREQ);
+
+ mutex_unlock(&tio->lock);
+}
+
+static void intel_pmc_tio_start_input_work(struct intel_pmc_tio_chip *tio)
+{
+ if (tio->input_work_running)
+ return;
+
+ tio->systime_index = 0;
+ tio->systime_valid = false;
+ ktime_get_snapshot(&tio->systime_snapshot[tio->systime_index]);
+
+ schedule_delayed_work(&tio->input_work, HZ / INPUT_SNAPSHOT_FREQ);
+ tio->input_work_running = true;
+}
+
+static void intel_pmc_tio_stop_input_work(struct intel_pmc_tio_chip *tio)
+{
+ if (!tio->input_work_running)
+ return;
+
+ cancel_delayed_work_sync(&tio->input_work);
+ tio->input_work_running = false;
+}
+
+static int intel_pmc_tio_setup_poll(struct gpio_chip *chip, unsigned int offset,
+ u32 *eflags)
+{
+ struct intel_pmc_tio_chip *tio;
+
+ if (offset != 0)
+ return -EINVAL;
+
+ tio = gch_to_intel_pmc_tio(chip);
+
+ mutex_lock(&tio->lock);
+ intel_pmc_tio_start_input_work(tio);
+ intel_pmc_tio_enable_input(tio, *eflags);
+ mutex_unlock(&tio->lock);
+
+ return 0;
+}
+
+static int intel_pmc_tio_get_time(ktime_t *device_time,
+ struct system_counterval_t *system_counterval,
+ void *ctx)
+{
+ struct intel_pmc_tio_get_time_arg *arg = (typeof(arg))ctx;
+ struct intel_pmc_tio_chip *tio = arg->tio;
+ u32 flags = arg->eflags;
+ u64 abs_event_count;
+ u32 rel_event_count;
+ u64 art_timestamp;
+ u32 dt_hi_s;
+ u32 dt_hi_e;
+ int err = 0;
+ u32 dt_lo;
+
+ /* Upper 64 bits of TCV are unlocked, don't use */
+ dt_hi_s = read_art_time() >> 32;
+ dt_lo = INTEL_PMC_TIO_RD_REG(TGPIOTCV31_0);
+ abs_event_count = INTEL_PMC_TIO_RD_REG(TGPIOECCV63_32);
+ abs_event_count <<= 32;
+ abs_event_count |= INTEL_PMC_TIO_RD_REG(TGPIOECCV31_0);
+ dt_hi_e = read_art_time() >> 32;
+
+ art_timestamp = ((dt_hi_e != dt_hi_s) && !(dt_lo & 0x80000000)) ?
+ dt_hi_e : dt_hi_s;
+ art_timestamp <<= 32;
+ art_timestamp |= dt_lo;
+
+ rel_event_count = abs_event_count - tio->last_event_count;
+ if (rel_event_count == 0 || art_timestamp == tio->last_art_timestamp) {
+ err = -EAGAIN;
+ goto out;
+ }
+
+ tio->last_art_timestamp = art_timestamp;
+
+ *system_counterval = convert_art_to_tsc(art_timestamp);
+ arg->abs_event_count = abs_event_count;
+ arg->event_id = 0;
+ arg->event_id |= (flags & GPIO_V2_LINE_FLAG_EDGE_RISING) ?
+ GPIO_V2_LINE_EVENT_RISING_EDGE : 0;
+ arg->event_id |= (flags & GPIO_V2_LINE_FLAG_EDGE_FALLING) ?
+ GPIO_V2_LINE_EVENT_FALLING_EDGE : 0;
+
+out:
+ return err;
+}
+
+static int intel_pmc_tio_do_poll(struct gpio_chip *chip, unsigned int offset,
+ u32 eflags, struct gpioevent_poll_data *data)
+{
+ struct intel_pmc_tio_chip *tio = gch_to_intel_pmc_tio(chip);
+ struct intel_pmc_tio_get_time_arg arg = {
+ .eflags = eflags, .tio = tio };
+ struct system_device_crosststamp xtstamp;
+ unsigned int i, stop;
+ int err = -EAGAIN;
+
+ mutex_lock(&tio->lock);
+
+ i = tio->systime_index;
+ stop = tio->systime_valid ?
+ tio->systime_index : INPUT_SNAPSHOT_COUNT - 1;
+ do {
+ err = get_device_system_crosststamp(intel_pmc_tio_get_time,
+ &arg,
+ &tio->systime_snapshot[i],
+ &xtstamp);
+ if (!err) {
+ data->timestamp = ktime_to_ns(xtstamp.sys_realtime);
+ data->id = arg.event_id;
+ tio->last_event_count = arg.abs_event_count;
+ }
+ if (!err || err == -EAGAIN)
+ break;
+ i = (i + (INPUT_SNAPSHOT_COUNT - 1)) % INPUT_SNAPSHOT_COUNT;
+ } while (i != stop);
+
+ mutex_unlock(&tio->lock);
+
+ return err;
+}
+
static int intel_pmc_tio_probe(struct platform_device *pdev)
{
struct intel_pmc_tio_chip *tio;
@@ -111,10 +323,14 @@ static int intel_pmc_tio_probe(struct platform_device *pdev)
debugfs_create_regset32("regdump", 0444, tio->root, tio->regset);
tio->gch.label = pdev->name;
- tio->gch.ngpio = 0;
+ tio->gch.ngpio = GPIO_COUNT;
tio->gch.base = -1;
+ tio->gch.setup_poll = intel_pmc_tio_setup_poll;
+ tio->gch.do_poll = intel_pmc_tio_do_poll;
platform_set_drvdata(pdev, tio);
+ mutex_init(&tio->lock);
+ INIT_DELAYED_WORK(&tio->input_work, intel_pmc_tio_input_work);
err = devm_gpiochip_add_data(&pdev->dev, &tio->gch, tio);
if (err < 0)
@@ -136,6 +352,8 @@ static int intel_pmc_tio_remove(struct platform_device *pdev)
if (!tio)
return -ENODEV;
+ intel_pmc_tio_stop_input_work(tio);
+ mutex_destroy(&tio->lock);
debugfs_remove_recursive(tio->root);
return 0;