button: qcom-pmic: introduce Qualcomm PMIC button driver
Qualcomm PMICs include a "pon" function which handles two buttons, the
power button and "resin" button (usually volume down). Introduce a new
driver following upstream Linux DT to enable these and map them to Enter
and Down respectively to enable use in boot menus.
Signed-off-by: Caleb Connolly <caleb.connolly@linaro.org>
diff --git a/drivers/button/button-qcom-pmic.c b/drivers/button/button-qcom-pmic.c
new file mode 100644
index 0000000..34a976d
--- /dev/null
+++ b/drivers/button/button-qcom-pmic.c
@@ -0,0 +1,165 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Qualcomm generic pmic gpio driver
+ *
+ * (C) Copyright 2015 Mateusz Kulikowski <mateusz.kulikowski@gmail.com>
+ * (C) Copyright 2023 Linaro Ltd.
+ */
+
+#include <button.h>
+#include <dt-bindings/input/linux-event-codes.h>
+#include <dm.h>
+#include <dm/device-internal.h>
+#include <dm/lists.h>
+#include <log.h>
+#include <power/pmic.h>
+#include <spmi/spmi.h>
+#include <linux/bitops.h>
+
+#define REG_TYPE 0x4
+#define REG_SUBTYPE 0x5
+
+struct qcom_pmic_btn_priv {
+ u32 base;
+ u32 status_bit;
+ int code;
+ struct udevice *pmic;
+};
+
+#define PON_INT_RT_STS 0x10
+#define KPDPWR_ON_INT_BIT 0
+#define RESIN_ON_INT_BIT 1
+
+#define NODE_IS_PWRKEY(node) (!strncmp(ofnode_get_name(node), "pwrkey", strlen("pwrkey")))
+#define NODE_IS_RESIN(node) (!strncmp(ofnode_get_name(node), "resin", strlen("resin")))
+
+static enum button_state_t qcom_pwrkey_get_state(struct udevice *dev)
+{
+ struct qcom_pmic_btn_priv *priv = dev_get_priv(dev);
+
+ int reg = pmic_reg_read(priv->pmic, priv->base + PON_INT_RT_STS);
+
+ if (reg < 0)
+ return 0;
+
+ return (reg & BIT(priv->status_bit)) != 0;
+}
+
+static int qcom_pwrkey_get_code(struct udevice *dev)
+{
+ struct qcom_pmic_btn_priv *priv = dev_get_priv(dev);
+
+ return priv->code;
+}
+
+static int qcom_pwrkey_probe(struct udevice *dev)
+{
+ struct button_uc_plat *uc_plat = dev_get_uclass_plat(dev);
+ struct qcom_pmic_btn_priv *priv = dev_get_priv(dev);
+ ofnode node = dev_ofnode(dev);
+ int ret;
+ u64 base;
+
+ /* Ignore the top-level pon node */
+ if (!uc_plat->label)
+ return 0;
+
+ /* the pwrkey and resin nodes are children of the "pon" node, get the
+ * PMIC device to use in pmic_reg_* calls.
+ */
+ priv->pmic = dev->parent->parent;
+
+ /* Get the address of the parent pon node */
+ base = dev_read_addr(dev->parent);
+ if (base == FDT_ADDR_T_NONE) {
+ printf("%s: Can't find address\n", dev->name);
+ return -EINVAL;
+ }
+
+ priv->base = base;
+
+ /* Do a sanity check */
+ ret = pmic_reg_read(priv->pmic, priv->base + REG_TYPE);
+ if (ret != 0x1 && ret != 0xb) {
+ printf("%s: unexpected PMIC function type %d\n", dev->name, ret);
+ return -ENXIO;
+ }
+
+ ret = pmic_reg_read(priv->pmic, priv->base + REG_SUBTYPE);
+ if ((ret & 0x7) == 0) {
+ printf("%s: unexpected PMCI function subtype %d\n", dev->name, ret);
+ return -ENXIO;
+ }
+
+ if (NODE_IS_PWRKEY(node)) {
+ priv->status_bit = 0;
+ priv->code = KEY_ENTER;
+ } else if (NODE_IS_RESIN(node)) {
+ priv->status_bit = 1;
+ priv->code = KEY_DOWN;
+ } else {
+ /* Should not get here! */
+ printf("Invalid pon node '%s' should be 'pwrkey' or 'resin'\n",
+ ofnode_get_name(node));
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+static int button_qcom_pmic_bind(struct udevice *parent)
+{
+ struct udevice *dev;
+ ofnode node;
+ int ret;
+
+ dev_for_each_subnode(node, parent) {
+ struct button_uc_plat *uc_plat;
+ const char *label;
+
+ if (!ofnode_is_enabled(node))
+ continue;
+
+ ret = device_bind_driver_to_node(parent, "qcom_pwrkey",
+ ofnode_get_name(node),
+ node, &dev);
+ if (ret) {
+ printf("Failed to bind %s! %d\n", label, ret);
+ return ret;
+ }
+ uc_plat = dev_get_uclass_plat(dev);
+ if (NODE_IS_PWRKEY(node)) {
+ uc_plat->label = "pwrkey";
+ } else if (NODE_IS_RESIN(node)) {
+ uc_plat->label = "vol_down";
+ } else {
+ printf("Unknown button node '%s' should be 'pwrkey' or 'resin'\n",
+ ofnode_get_name(node));
+ device_unbind(dev);
+ }
+ }
+
+ return 0;
+}
+
+static const struct button_ops button_qcom_pmic_ops = {
+ .get_state = qcom_pwrkey_get_state,
+ .get_code = qcom_pwrkey_get_code,
+};
+
+static const struct udevice_id qcom_pwrkey_ids[] = {
+ { .compatible = "qcom,pm8916-pon" },
+ { .compatible = "qcom,pm8941-pon" },
+ { .compatible = "qcom,pm8998-pon" },
+ { }
+};
+
+U_BOOT_DRIVER(qcom_pwrkey) = {
+ .name = "qcom_pwrkey",
+ .id = UCLASS_BUTTON,
+ .of_match = qcom_pwrkey_ids,
+ .bind = button_qcom_pmic_bind,
+ .probe = qcom_pwrkey_probe,
+ .ops = &button_qcom_pmic_ops,
+ .priv_auto = sizeof(struct qcom_pmic_btn_priv),
+};