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From:   ShuFanLee <leechu729@gmail.com>
To:     heikki.krogerus@linux.intel.com, linux@roeck-us.net
Cc:     linux-kernel@vger.kernel.org, linux-usb@vger.kernel.org,
        cy_huang@richtek.com, shufan_lee@richtek.com
Subject: [PATCH] staging: typec: handle vendor defined part and modify drp toggling flow
Date:   Wed, 14 Feb 2018 17:24:04 +0800
Message-Id: <1518600244-29949-1-git-send-email-leechu729@gmail.com>
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

From: ShuFanLee <shufan_lee@richtek.com>

Handle vendor defined behavior in tcpci_init and tcpci_irq.
More operations can be extended in tcpci_vendor_data if needed.
According to TCPCI specification, 4.4.5.2 ROLE_CONTROL,
TCPC shall not start DRP toggling until subsequently the TCPM
writes to the COMMAND register to start DRP toggling.
DRP toggling flow is chagned as following:
  - Write DRP = 0 & Rd/Rd
  - Write DRP = 1
  - Set LOOK4CONNECTION command

Signed-off-by: ShuFanLee <shufan_lee@richtek.com>
---
 drivers/staging/typec/tcpci.c | 98 ++++++++++++++++++++++++++++++++++++-------
 drivers/staging/typec/tcpci.h | 15 +++++++
 2 files changed, 97 insertions(+), 16 deletions(-)

diff --git a/drivers/staging/typec/tcpci.c b/drivers/staging/typec/tcpci.c
index 9bd4412..b3a97b3 100644
--- a/drivers/staging/typec/tcpci.c
+++ b/drivers/staging/typec/tcpci.c
@@ -30,6 +30,7 @@ struct tcpci {
 	bool controls_vbus;
 
 	struct tcpc_dev tcpc;
+	struct tcpci_vendor_data *vdata;
 };
 
 static inline struct tcpci *tcpc_to_tcpci(struct tcpc_dev *tcpc)
@@ -37,16 +38,29 @@ static inline struct tcpci *tcpc_to_tcpci(struct tcpc_dev *tcpc)
 	return container_of(tcpc, struct tcpci, tcpc);
 }
 
-static int tcpci_read16(struct tcpci *tcpci, unsigned int reg,
-			u16 *val)
+int tcpci_read16(struct tcpci *tcpci, unsigned int reg, u16 *val)
 {
 	return regmap_raw_read(tcpci->regmap, reg, val, sizeof(u16));
 }
+EXPORT_SYMBOL_GPL(tcpci_read16);
 
-static int tcpci_write16(struct tcpci *tcpci, unsigned int reg, u16 val)
+int tcpci_write16(struct tcpci *tcpci, unsigned int reg, u16 val)
 {
 	return regmap_raw_write(tcpci->regmap, reg, &val, sizeof(u16));
 }
+EXPORT_SYMBOL_GPL(tcpci_write16);
+
+int tcpci_read8(struct tcpci *tcpci, unsigned int reg, u8 *val)
+{
+	return regmap_raw_read(tcpci->regmap, reg, val, sizeof(u8));
+}
+EXPORT_SYMBOL_GPL(tcpci_read8);
+
+int tcpci_write8(struct tcpci *tcpci, unsigned int reg, u8 val)
+{
+	return regmap_raw_write(tcpci->regmap, reg, &val, sizeof(u8));
+}
+EXPORT_SYMBOL_GPL(tcpci_write8);
 
 static int tcpci_set_cc(struct tcpc_dev *tcpc, enum typec_cc_status cc)
 {
@@ -98,8 +112,10 @@ static int tcpci_set_cc(struct tcpc_dev *tcpc, enum typec_cc_status cc)
 static int tcpci_start_drp_toggling(struct tcpc_dev *tcpc,
 				    enum typec_cc_status cc)
 {
+	int ret;
 	struct tcpci *tcpci = tcpc_to_tcpci(tcpc);
-	unsigned int reg = TCPC_ROLE_CTRL_DRP;
+	unsigned int reg = (TCPC_ROLE_CTRL_CC_RD << TCPC_ROLE_CTRL_CC1_SHIFT) |
+			   (TCPC_ROLE_CTRL_CC_RD << TCPC_ROLE_CTRL_CC2_SHIFT);
 
 	switch (cc) {
 	default:
@@ -116,8 +132,19 @@ static int tcpci_start_drp_toggling(struct tcpc_dev *tcpc,
 			TCPC_ROLE_CTRL_RP_VAL_SHIFT);
 		break;
 	}
-
-	return regmap_write(tcpci->regmap, TCPC_ROLE_CTRL, reg);
+	ret = regmap_write(tcpci->regmap, TCPC_ROLE_CTRL, reg);
+	if (ret < 0)
+		return ret;
+	usleep_range(500, 1000);
+	reg |= TCPC_ROLE_CTRL_DRP;
+	ret = regmap_write(tcpci->regmap, TCPC_ROLE_CTRL, reg);
+	if (ret < 0)
+		return ret;
+	ret = regmap_write(tcpci->regmap, TCPC_COMMAND,
+			   TCPC_CMD_LOOK4CONNECTION);
+	if (ret < 0)
+		return ret;
+	return 0;
 }
 
 static enum typec_cc_status tcpci_to_typec_cc(unsigned int cc, bool sink)
@@ -323,6 +350,15 @@ static int tcpci_init(struct tcpc_dev *tcpc)
 	if (time_after(jiffies, timeout))
 		return -ETIMEDOUT;
 
+	/* Handle vendor init */
+	if (tcpci->vdata) {
+		if (tcpci->vdata->init) {
+			ret = (*tcpci->vdata->init)(tcpci, tcpci->vdata);
+			if (ret < 0)
+				return ret;
+		}
+	}
+
 	/* Clear all events */
 	ret = tcpci_write16(tcpci, TCPC_ALERT, 0xffff);
 	if (ret < 0)
@@ -351,6 +387,13 @@ static irqreturn_t tcpci_irq(int irq, void *dev_id)
 
 	tcpci_read16(tcpci, TCPC_ALERT, &status);
 
+	/* Handle vendor defined interrupt */
+	if (tcpci->vdata) {
+		if (tcpci->vdata->irq_handler)
+			(*tcpci->vdata->irq_handler)(tcpci, tcpci->vdata,
+						     &status);
+	}
+
 	/*
 	 * Clear alert status for everything except RX_STATUS, which shouldn't
 	 * be cleared until we have successfully retrieved message.
@@ -417,7 +460,7 @@ static irqreturn_t tcpci_irq(int irq, void *dev_id)
 	.reg_bits = 8,
 	.val_bits = 8,
 
-	.max_register = 0x7F, /* 0x80 .. 0xFF are vendor defined */
+	.max_register = 0xFF, /* 0x80 .. 0xFF are vendor defined */
 };
 
 static const struct tcpc_config tcpci_tcpc_config = {
@@ -435,22 +478,22 @@ static int tcpci_parse_config(struct tcpci *tcpci)
 	return 0;
 }
 
-static int tcpci_probe(struct i2c_client *client,
-		       const struct i2c_device_id *i2c_id)
+struct tcpci *tcpci_register_port(struct i2c_client *client,
+				  struct tcpci_vendor_data *vdata)
 {
 	struct tcpci *tcpci;
 	int err;
 
 	tcpci = devm_kzalloc(&client->dev, sizeof(*tcpci), GFP_KERNEL);
 	if (!tcpci)
-		return -ENOMEM;
+		return ERR_PTR(-ENOMEM);
 
 	tcpci->client = client;
 	tcpci->dev = &client->dev;
-	i2c_set_clientdata(client, tcpci);
+	tcpci->vdata = vdata;
 	tcpci->regmap = devm_regmap_init_i2c(client, &tcpci_regmap_config);
 	if (IS_ERR(tcpci->regmap))
-		return PTR_ERR(tcpci->regmap);
+		return ERR_CAST(tcpci->regmap);
 
 	tcpci->tcpc.init = tcpci_init;
 	tcpci->tcpc.get_vbus = tcpci_get_vbus;
@@ -467,7 +510,7 @@ static int tcpci_probe(struct i2c_client *client,
 
 	err = tcpci_parse_config(tcpci);
 	if (err < 0)
-		return err;
+		return ERR_PTR(err);
 
 	/* Disable chip interrupts */
 	tcpci_write16(tcpci, TCPC_ALERT_MASK, 0);
@@ -477,17 +520,40 @@ static int tcpci_probe(struct i2c_client *client,
 					IRQF_ONESHOT | IRQF_TRIGGER_LOW,
 					dev_name(tcpci->dev), tcpci);
 	if (err < 0)
-		return err;
+		return ERR_PTR(err);
 
 	tcpci->port = tcpm_register_port(tcpci->dev, &tcpci->tcpc);
-	return PTR_ERR_OR_ZERO(tcpci->port);
+	if (PTR_ERR_OR_ZERO(tcpci->port))
+		return ERR_CAST(tcpci->port);
+
+	return tcpci;
+}
+EXPORT_SYMBOL_GPL(tcpci_register_port);
+
+void tcpci_unregister_port(struct tcpci *tcpci)
+{
+	tcpm_unregister_port(tcpci->port);
+}
+EXPORT_SYMBOL_GPL(tcpci_unregister_port);
+
+static int tcpci_probe(struct i2c_client *client,
+		       const struct i2c_device_id *i2c_id)
+{
+	struct tcpci *tcpci;
+
+	tcpci = tcpci_register_port(client, NULL);
+	if (PTR_ERR_OR_ZERO(tcpci))
+		return PTR_ERR(tcpci);
+
+	i2c_set_clientdata(client, tcpci);
+	return 0;
 }
 
 static int tcpci_remove(struct i2c_client *client)
 {
 	struct tcpci *tcpci = i2c_get_clientdata(client);
 
-	tcpm_unregister_port(tcpci->port);
+	tcpci_unregister_port(tcpci);
 
 	return 0;
 }
diff --git a/drivers/staging/typec/tcpci.h b/drivers/staging/typec/tcpci.h
index fdfb06c..b1fcb4a 100644
--- a/drivers/staging/typec/tcpci.h
+++ b/drivers/staging/typec/tcpci.h
@@ -59,6 +59,7 @@
 #define TCPC_POWER_CTRL_VCONN_ENABLE	BIT(0)
 
 #define TCPC_CC_STATUS			0x1d
+#define TCPC_CC_STATUS_DRPRST		BIT(5)
 #define TCPC_CC_STATUS_TERM		BIT(4)
 #define TCPC_CC_STATUS_CC2_SHIFT	2
 #define TCPC_CC_STATUS_CC2_MASK		0x3
@@ -121,4 +122,18 @@
 #define TCPC_VBUS_VOLTAGE_ALARM_HI_CFG		0x76
 #define TCPC_VBUS_VOLTAGE_ALARM_LO_CFG		0x78
 
+struct tcpci;
+struct tcpci_vendor_data {
+	int (*init)(struct tcpci *tcpci, struct tcpci_vendor_data *data);
+	int (*irq_handler)(struct tcpci *tcpci, struct tcpci_vendor_data *data,
+			   u16 *status);
+};
+
+int tcpci_read16(struct tcpci *tcpci, unsigned int reg, u16 *val);
+int tcpci_write16(struct tcpci *tcpci, unsigned int reg, u16 val);
+int tcpci_read8(struct tcpci *tcpci, unsigned int reg, u8 *val);
+int tcpci_write8(struct tcpci *tcpci, unsigned int reg, u8 val);
+struct tcpci *tcpci_register_port(struct i2c_client *client,
+				  struct tcpci_vendor_data *data);
+void tcpci_unregister_port(struct tcpci *tcpci);
 #endif /* __LINUX_USB_TCPCI_H */
-- 
1.9.1