[PATCH 9/9] phy: ti: tusb1210: Add charger detection
Hans de Goede
hdegoede at redhat.com
Sat Feb 5 08:45:35 PST 2022
From: Stephan Gerhold <stephan at gerhold.net>
Some Android x86 tablets with a Bay Trail (BYT) SoC and a Crystal Cove
PMIC, which does not support charger-detection, rely on a TUSB1211
phy for charger-detection.
Add support for charger detection on TUSB1211 phy-s and export
the information about the detected charger through the standard
power_supply class interface. power_supply class charger IC drivers
like the bq24190_charger.c driver will then pick this up and set
their input_current_limit based on this.
Note the "linux,phy_charger_detect" property used to enable this is
a special kernel-internal (so not part of the dt-bindings) property
used by dwc3 platform code to indicate that the phy needs to do
charger-detection.
Changes by Hans de Goede:
- Use "linux,phy_charger_detect" property to enable charger-detect
- Switch from a linear flow to a state-machine, with retries on
ulpi communication errors
- Use SW_CONTROL bit to disable the FSM when detection is finished
- Do a phy-reset on disconnect to work around the phy often refusing
ulpi_read()/_write() commands after a disconnect
- Use power_supply_reg_notifier() for Vbus monitoring
- Export the detection result through a power_supply class device
Signed-off-by: Stephan Gerhold <stephan at gerhold.net>
Co-developed-by: Hans de Goede <hdegoede at redhat.com>
Signed-off-by: Hans de Goede <hdegoede at redhat.com>
---
drivers/phy/ti/phy-tusb1210.c | 321 +++++++++++++++++++++++++++++++++-
1 file changed, 314 insertions(+), 7 deletions(-)
diff --git a/drivers/phy/ti/phy-tusb1210.c b/drivers/phy/ti/phy-tusb1210.c
index 9ef4c5f79b75..d2782a525091 100644
--- a/drivers/phy/ti/phy-tusb1210.c
+++ b/drivers/phy/ti/phy-tusb1210.c
@@ -13,20 +13,58 @@
#include <linux/ulpi/regs.h>
#include <linux/gpio/consumer.h>
#include <linux/phy/ulpi_phy.h>
-
-#define TUSB1210_VENDOR_SPECIFIC2 0x80
-#define TUSB1210_VENDOR_SPECIFIC2_IHSTX_MASK GENMASK(3, 0)
-#define TUSB1210_VENDOR_SPECIFIC2_ZHSDRV_MASK GENMASK(5, 4)
-#define TUSB1210_VENDOR_SPECIFIC2_DP_MASK BIT(6)
-
-#define TUSB1210_RESET_TIME_MS 30
+#include <linux/power_supply.h>
+#include <linux/workqueue.h>
+
+#define TUSB1211_POWER_CONTROL 0x3d
+#define TUSB1211_POWER_CONTROL_SET 0x3e
+#define TUSB1211_POWER_CONTROL_CLEAR 0x3f
+#define TUSB1211_POWER_CONTROL_SW_CONTROL BIT(0)
+#define TUSB1211_POWER_CONTROL_DET_COMP BIT(1)
+#define TUSB1211_POWER_CONTROL_DP_VSRC_EN BIT(6)
+
+#define TUSB1210_VENDOR_SPECIFIC2 0x80
+#define TUSB1210_VENDOR_SPECIFIC2_IHSTX_MASK GENMASK(3, 0)
+#define TUSB1210_VENDOR_SPECIFIC2_ZHSDRV_MASK GENMASK(5, 4)
+#define TUSB1210_VENDOR_SPECIFIC2_DP_MASK BIT(6)
+
+#define TUSB1211_VENDOR_SPECIFIC3 0x85
+#define TUSB1211_VENDOR_SPECIFIC3_SET 0x86
+#define TUSB1211_VENDOR_SPECIFIC3_CLEAR 0x87
+#define TUSB1211_VENDOR_SPECIFIC3_SW_USB_DET BIT(4)
+#define TUSB1211_VENDOR_SPECIFIC3_CHGD_IDP_SRC_EN BIT(6)
+
+#define TUSB1210_RESET_TIME_MS 50
+
+#define TUSB1210_CHG_DET_MAX_RETRIES 5
+
+/* TUSB1210 charger detection work states */
+enum tusb1210_chg_det_state {
+ TUSB1210_CHG_DET_CONNECTING,
+ TUSB1210_CHG_DET_START_DET,
+ TUSB1210_CHG_DET_READ_DET,
+ TUSB1210_CHG_DET_FINISH_DET,
+ TUSB1210_CHG_DET_CONNECTED,
+ TUSB1210_CHG_DET_DISCONNECTING,
+ TUSB1210_CHG_DET_DISCONNECTING_DONE,
+ TUSB1210_CHG_DET_DISCONNECTED,
+};
struct tusb1210 {
struct ulpi *ulpi;
struct phy *phy;
struct gpio_desc *gpio_reset;
struct gpio_desc *gpio_cs;
+ u8 otg_ctrl;
u8 vendor_specific2;
+#ifdef CONFIG_POWER_SUPPLY
+ enum power_supply_usb_type chg_type;
+ enum tusb1210_chg_det_state chg_det_state;
+ int chg_det_retries;
+ struct delayed_work chg_det_work;
+ struct notifier_block psy_nb;
+ struct power_supply *psy;
+#endif
};
static int tusb1210_ulpi_write(struct tusb1210 *tusb, u8 reg, u8 val)
@@ -111,9 +149,276 @@ static int tusb1210_set_mode(struct phy *phy, enum phy_mode mode, int submode)
return 0;
}
+ tusb->otg_ctrl = reg;
return tusb1210_ulpi_write(tusb, ULPI_OTG_CTRL, reg);
}
+#ifdef CONFIG_POWER_SUPPLY
+const char * const tusb1210_chg_det_states[] = {
+ "CHG_DET_CONNECTING",
+ "CHG_DET_START_DET",
+ "CHG_DET_READ_DET",
+ "CHG_DET_FINISH_DET",
+ "CHG_DET_CONNECTED",
+ "CHG_DET_DISCONNECTING",
+ "CHG_DET_DISCONNECTING_DONE",
+ "CHG_DET_DISCONNECTED",
+};
+
+static void tusb1210_reset(struct tusb1210 *tusb)
+{
+ gpiod_set_value_cansleep(tusb->gpio_reset, 0);
+ usleep_range(200, 500);
+ gpiod_set_value_cansleep(tusb->gpio_reset, 1);
+}
+
+static void tusb1210_chg_det_set_type(struct tusb1210 *tusb,
+ enum power_supply_usb_type type)
+{
+ dev_dbg(&tusb->ulpi->dev, "charger type: %d\n", type);
+ tusb->chg_type = type;
+ tusb->chg_det_retries = 0;
+ power_supply_changed(tusb->psy);
+}
+
+static void tusb1210_chg_det_set_state(struct tusb1210 *tusb,
+ enum tusb1210_chg_det_state new_state,
+ int delay_ms)
+{
+ if (delay_ms)
+ dev_dbg(&tusb->ulpi->dev, "chg_det new state %s in %d ms\n",
+ tusb1210_chg_det_states[new_state], delay_ms);
+
+ tusb->chg_det_state = new_state;
+ mod_delayed_work(system_long_wq, &tusb->chg_det_work,
+ msecs_to_jiffies(delay_ms));
+}
+
+static void tusb1210_chg_det_handle_ulpi_error(struct tusb1210 *tusb)
+{
+ tusb1210_reset(tusb);
+ if (tusb->chg_det_retries < TUSB1210_CHG_DET_MAX_RETRIES) {
+ tusb->chg_det_retries++;
+ tusb1210_chg_det_set_state(tusb, TUSB1210_CHG_DET_START_DET,
+ TUSB1210_RESET_TIME_MS);
+ } else {
+ tusb1210_chg_det_set_state(tusb, TUSB1210_CHG_DET_FINISH_DET,
+ TUSB1210_RESET_TIME_MS);
+ }
+}
+
+static void tusb1210_chg_det_work(struct work_struct *work)
+{
+ struct tusb1210 *tusb = container_of(work, struct tusb1210, chg_det_work.work);
+ bool vbus_present = power_supply_is_system_supplied();
+ int ret;
+ u8 val;
+
+ dev_dbg(&tusb->ulpi->dev, "chg_det state %s vbus_present %d\n",
+ tusb1210_chg_det_states[tusb->chg_det_state], vbus_present);
+
+ switch (tusb->chg_det_state) {
+ case TUSB1210_CHG_DET_CONNECTING:
+ tusb->chg_type = POWER_SUPPLY_USB_TYPE_UNKNOWN;
+ tusb->chg_det_retries = 0;
+ /* Power on USB controller for ulpi_read()/_write() */
+ ret = pm_runtime_resume_and_get(tusb->ulpi->dev.parent);
+ if (ret < 0) {
+ dev_err(&tusb->ulpi->dev, "error %d runtime-resuming\n", ret);
+ /* Should never happen, skip charger detection */
+ tusb1210_chg_det_set_state(tusb, TUSB1210_CHG_DET_CONNECTED, 0);
+ return;
+ }
+ tusb1210_chg_det_set_state(tusb, TUSB1210_CHG_DET_START_DET, 0);
+ break;
+ case TUSB1210_CHG_DET_START_DET:
+ /*
+ * Use the builtin charger detection FSM to keep things simple.
+ * This only detects DCP / SDP. This is good enough for the few
+ * boards which actually rely on the phy for charger detection.
+ */
+ mutex_lock(&tusb->phy->mutex);
+ ret = tusb1210_ulpi_write(tusb, TUSB1211_VENDOR_SPECIFIC3_SET,
+ TUSB1211_VENDOR_SPECIFIC3_SW_USB_DET);
+ mutex_unlock(&tusb->phy->mutex);
+ if (ret) {
+ tusb1210_chg_det_handle_ulpi_error(tusb);
+ break;
+ }
+
+ /* Wait 400 ms for the charger detection FSM to finish */
+ tusb1210_chg_det_set_state(tusb, TUSB1210_CHG_DET_READ_DET, 400);
+ break;
+ case TUSB1210_CHG_DET_READ_DET:
+ mutex_lock(&tusb->phy->mutex);
+ ret = tusb1210_ulpi_read(tusb, TUSB1211_POWER_CONTROL, &val);
+ mutex_unlock(&tusb->phy->mutex);
+ if (ret) {
+ tusb1210_chg_det_handle_ulpi_error(tusb);
+ break;
+ }
+
+ if (val & TUSB1211_POWER_CONTROL_DET_COMP)
+ tusb1210_chg_det_set_type(tusb, POWER_SUPPLY_USB_TYPE_DCP);
+ else
+ tusb1210_chg_det_set_type(tusb, POWER_SUPPLY_USB_TYPE_SDP);
+
+ tusb1210_chg_det_set_state(tusb, TUSB1210_CHG_DET_FINISH_DET, 0);
+ break;
+ case TUSB1210_CHG_DET_FINISH_DET:
+ mutex_lock(&tusb->phy->mutex);
+
+ /* Set SW_CONTROL to stop the charger-det FSM */
+ ret = tusb1210_ulpi_write(tusb, TUSB1211_POWER_CONTROL_SET,
+ TUSB1211_POWER_CONTROL_SW_CONTROL);
+
+ /* Clear DP_VSRC_EN which may have been enabled by the charger-det FSM */
+ ret |= tusb1210_ulpi_write(tusb, TUSB1211_POWER_CONTROL_CLEAR,
+ TUSB1211_POWER_CONTROL_DP_VSRC_EN);
+
+ /* Clear CHGD_IDP_SRC_EN (may have been enabled by the charger-det FSM) */
+ ret |= tusb1210_ulpi_write(tusb, TUSB1211_VENDOR_SPECIFIC3_CLEAR,
+ TUSB1211_VENDOR_SPECIFIC3_CHGD_IDP_SRC_EN);
+
+ /* If any of the above fails reset the phy */
+ if (ret) {
+ tusb1210_reset(tusb);
+ msleep(TUSB1210_RESET_TIME_MS);
+ }
+
+ /* Restore phy-parameters and OTG_CTRL register */
+ tusb1210_ulpi_write(tusb, ULPI_OTG_CTRL, tusb->otg_ctrl);
+ tusb1210_ulpi_write(tusb, TUSB1210_VENDOR_SPECIFIC2,
+ tusb->vendor_specific2);
+
+ mutex_unlock(&tusb->phy->mutex);
+
+ pm_runtime_put(tusb->ulpi->dev.parent);
+ tusb1210_chg_det_set_state(tusb, TUSB1210_CHG_DET_CONNECTED, 0);
+ break;
+ case TUSB1210_CHG_DET_CONNECTED:
+ if (!vbus_present)
+ tusb1210_chg_det_set_state(tusb, TUSB1210_CHG_DET_DISCONNECTING, 0);
+ break;
+ case TUSB1210_CHG_DET_DISCONNECTING:
+ /*
+ * The phy seems to take approx. 600ms longer then the charger
+ * chip (which is used to get vbus_present) to determine Vbus
+ * session end. Wait 800ms to ensure the phy has detected and
+ * signalled Vbus session end.
+ */
+ tusb1210_chg_det_set_state(tusb, TUSB1210_CHG_DET_DISCONNECTING_DONE, 800);
+ break;
+ case TUSB1210_CHG_DET_DISCONNECTING_DONE:
+ /*
+ * The phy often stops reacting to ulpi_read()/_write requests
+ * after a Vbus-session end. Reset it to work around this.
+ */
+ tusb1210_reset(tusb);
+ tusb1210_chg_det_set_type(tusb, POWER_SUPPLY_USB_TYPE_UNKNOWN);
+ tusb1210_chg_det_set_state(tusb, TUSB1210_CHG_DET_DISCONNECTED, 0);
+ break;
+ case TUSB1210_CHG_DET_DISCONNECTED:
+ if (vbus_present)
+ tusb1210_chg_det_set_state(tusb, TUSB1210_CHG_DET_CONNECTING, 0);
+ break;
+ }
+}
+
+static int tusb1210_psy_notifier(struct notifier_block *nb,
+ unsigned long event, void *ptr)
+{
+ struct tusb1210 *tusb = container_of(nb, struct tusb1210, psy_nb);
+ struct power_supply *psy = ptr;
+
+ if (psy != tusb->psy && psy->desc->type == POWER_SUPPLY_TYPE_USB)
+ queue_delayed_work(system_long_wq, &tusb->chg_det_work, 0);
+
+ return NOTIFY_OK;
+}
+
+static int tusb1210_psy_get_prop(struct power_supply *psy,
+ enum power_supply_property psp,
+ union power_supply_propval *val)
+{
+ struct tusb1210 *tusb = power_supply_get_drvdata(psy);
+
+ switch (psp) {
+ case POWER_SUPPLY_PROP_USB_TYPE:
+ val->intval = tusb->chg_type;
+ break;
+ case POWER_SUPPLY_PROP_CURRENT_MAX:
+ if (tusb->chg_type == POWER_SUPPLY_USB_TYPE_DCP)
+ val->intval = 2000000;
+ else
+ val->intval = 500000;
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+static const enum power_supply_usb_type tusb1210_psy_usb_types[] = {
+ POWER_SUPPLY_USB_TYPE_SDP,
+ POWER_SUPPLY_USB_TYPE_DCP,
+ POWER_SUPPLY_USB_TYPE_UNKNOWN,
+};
+
+static const enum power_supply_property tusb1210_psy_props[] = {
+ POWER_SUPPLY_PROP_USB_TYPE,
+ POWER_SUPPLY_PROP_CURRENT_MAX,
+};
+
+static const struct power_supply_desc tusb1210_psy_desc = {
+ .name = "tusb1211-charger-detect",
+ .type = POWER_SUPPLY_TYPE_USB,
+ .usb_types = tusb1210_psy_usb_types,
+ .num_usb_types = ARRAY_SIZE(tusb1210_psy_usb_types),
+ .properties = tusb1210_psy_props,
+ .num_properties = ARRAY_SIZE(tusb1210_psy_props),
+ .get_property = tusb1210_psy_get_prop,
+};
+
+/* Setup charger detection if requested, on errors continue without chg-det */
+static void tusb1210_init_charger_detect(struct tusb1210 *tusb)
+{
+ struct power_supply_config psy_cfg = { .drv_data = tusb };
+ struct device *dev = &tusb->ulpi->dev;
+ int ret;
+
+ if (!device_property_read_bool(dev->parent, "linux,phy_charger_detect"))
+ return;
+
+ if (tusb->ulpi->id.product != 0x1508) {
+ dev_err(dev, "error charger detection is only supported on the TUSB1211\n");
+ return;
+ }
+
+ ret = tusb1210_ulpi_read(tusb, ULPI_OTG_CTRL, &tusb->otg_ctrl);
+ if (ret)
+ return;
+
+ tusb->psy = devm_power_supply_register(dev, &tusb1210_psy_desc, &psy_cfg);
+ if (IS_ERR(tusb->psy))
+ return;
+
+ /*
+ * Delay initial run by 2 seconds to allow the charger driver,
+ * which is used to determine vbus_present, to load.
+ */
+ tusb->chg_det_state = TUSB1210_CHG_DET_DISCONNECTED;
+ INIT_DELAYED_WORK(&tusb->chg_det_work, tusb1210_chg_det_work);
+ queue_delayed_work(system_long_wq, &tusb->chg_det_work, 2 * HZ);
+
+ tusb->psy_nb.notifier_call = tusb1210_psy_notifier;
+ power_supply_reg_notifier(&tusb->psy_nb);
+}
+#else
+static void tusb1210_init_charger_detect(struct tusb1210 *tusb) { }
+#endif
+
static const struct phy_ops phy_ops = {
.power_on = tusb1210_power_on,
.power_off = tusb1210_power_off,
@@ -174,6 +479,8 @@ static int tusb1210_probe(struct ulpi *ulpi)
tusb->vendor_specific2 = reg;
+ tusb1210_init_charger_detect(tusb);
+
tusb->phy = ulpi_phy_create(ulpi, &phy_ops);
if (IS_ERR(tusb->phy))
return PTR_ERR(tusb->phy);
--
2.33.1
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