Re: [PATCH v2] staging: typec: handle vendor defined part and modify drp toggling flow

From: Guenter Roeck
Date: Wed Feb 14 2018 - 09:52:29 EST


On 02/14/2018 04:45 AM, ShuFanLee wrote:
From: ShuFanLee <shufan_lee@xxxxxxxxxxx>

Handle vendor defined behavior in tcpci_init, tcpci_set_vconn and export tcpci_irq.
More operations can be extended in tcpci_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@xxxxxxxxxxx>
---
drivers/staging/typec/tcpci.c | 111 ++++++++++++++++++++++++++++++++++--------
drivers/staging/typec/tcpci.h | 13 +++++
2 files changed, 103 insertions(+), 21 deletions(-)

diff --git a/drivers/staging/typec/tcpci.c b/drivers/staging/typec/tcpci.c
index 9bd4412..461fbd48 100644
--- a/drivers/staging/typec/tcpci.c
+++ b/drivers/staging/typec/tcpci.c
@@ -21,7 +21,6 @@
struct tcpci {
struct device *dev;
- struct i2c_client *client;
struct tcpm_port *port;
@@ -30,6 +29,7 @@ struct tcpci {
bool controls_vbus;
struct tcpc_dev tcpc;
+ struct tcpci_data *data;
};
static inline struct tcpci *tcpc_to_tcpci(struct tcpc_dev *tcpc)
@@ -98,8 +98,10 @@ 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 +118,19 @@ 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)
@@ -178,6 +191,16 @@ static int tcpci_set_vconn(struct tcpc_dev *tcpc, bool enable)
struct tcpci *tcpci = tcpc_to_tcpci(tcpc);
int ret;
+ /* Handle vendor set vconn */
+ if (tcpci->data) {
+ if (tcpci->data->set_vconn) {
+ ret = tcpci->data->set_vconn(tcpci, tcpci->data,
+ enable);
+ if (ret < 0)
+ return ret;
+ }
+ }
+
ret = regmap_write(tcpci->regmap, TCPC_POWER_CTRL,
enable ? TCPC_POWER_CTRL_VCONN_ENABLE : 0);
if (ret < 0)
@@ -323,6 +346,15 @@ static int tcpci_init(struct tcpc_dev *tcpc)
if (time_after(jiffies, timeout))
return -ETIMEDOUT;
+ /* Handle vendor init */
+ if (tcpci->data) {
+ if (tcpci->data->init) {
+ ret = tcpci->data->init(tcpci, tcpci->data);
+ if (ret < 0)
+ return ret;
+ }
+ }
+
/* Clear all events */
ret = tcpci_write16(tcpci, TCPC_ALERT, 0xffff);
if (ret < 0)
@@ -344,9 +376,16 @@ static int tcpci_init(struct tcpc_dev *tcpc)
return tcpci_write16(tcpci, TCPC_ALERT_MASK, reg);
}
-static irqreturn_t tcpci_irq(int irq, void *dev_id)
+static irqreturn_t _tcpci_irq(int irq, void *dev_id)
{
struct tcpci *tcpci = dev_id;
+
+ tcpci_irq(tcpci);
+ return IRQ_HANDLED;

This should probably be
return tcpci_irq(tcpci);

+}
+
+int tcpci_irq(struct tcpci *tcpci)

and this should be

irqreturn_t tcpci_irq(struct tcpci *tcpci)

Otherwise it doesn't add value to have tcpci_irq() return anything.
Alternative would be to make it

void tcpci_irq(struct tcpci *tcpci)

if it will always only return IRQ_HANDLED.

Guenter

+{
u16 status;
tcpci_read16(tcpci, TCPC_ALERT, &status);
@@ -412,6 +451,7 @@ static irqreturn_t tcpci_irq(int irq, void *dev_id)
return IRQ_HANDLED;
}
+EXPORT_SYMBOL_GPL(tcpci_irq);
static const struct regmap_config tcpci_regmap_config = {
.reg_bits = 8,
@@ -435,22 +475,18 @@ 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 device *dev, struct tcpci_data *data)
{
struct tcpci *tcpci;
int err;
- tcpci = devm_kzalloc(&client->dev, sizeof(*tcpci), GFP_KERNEL);
+ tcpci = devm_kzalloc(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->regmap = devm_regmap_init_i2c(client, &tcpci_regmap_config);
- if (IS_ERR(tcpci->regmap))
- return PTR_ERR(tcpci->regmap);
+ tcpci->dev = dev;
+ tcpci->data = data;
+ tcpci->regmap = data->regmap;
tcpci->tcpc.init = tcpci_init;
tcpci->tcpc.get_vbus = tcpci_get_vbus;
@@ -467,27 +503,60 @@ 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);
- err = devm_request_threaded_irq(tcpci->dev, client->irq, NULL,
- tcpci_irq,
+ tcpci->port = tcpm_register_port(tcpci->dev, &tcpci->tcpc);
+ 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;
+ struct tcpci_data *data;
+ int err;
+
+ data = devm_kzalloc(&client->dev, sizeof(*data), GFP_KERNEL);
+ if (!data)
+ return -ENOMEM;
+
+ data->regmap = devm_regmap_init_i2c(client, &tcpci_regmap_config);
+ if (IS_ERR(data->regmap))
+ return PTR_ERR(data->regmap);
+
+ tcpci = tcpci_register_port(&client->dev, data);
+ if (PTR_ERR_OR_ZERO(tcpci))
+ return PTR_ERR(tcpci);
+
+ err = devm_request_threaded_irq(&client->dev, client->irq, NULL,
+ _tcpci_irq,
IRQF_ONESHOT | IRQF_TRIGGER_LOW,
dev_name(tcpci->dev), tcpci);

I am a bit concerned that this may cause problems, since tcpm_register_port()
will send messages to the driver, which may trigger interrupts. It may be
necessary to register interrupts early, prior to calling tcpci_register_port().

if (err < 0)
return err;

You'll need to call tcpm_unregister_port() here (or register the interrupt first).

Guenter

- tcpci->port = tcpm_register_port(tcpci->dev, &tcpci->tcpc);
- return PTR_ERR_OR_ZERO(tcpci->port);
+ 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..c838723 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 +122,16 @@
#define TCPC_VBUS_VOLTAGE_ALARM_HI_CFG 0x76
#define TCPC_VBUS_VOLTAGE_ALARM_LO_CFG 0x78
+struct tcpci;
+struct tcpci_data {
+ struct regmap *regmap;
+ int (*init)(struct tcpci *tcpci, struct tcpci_data *data);
+ int (*set_vconn)(struct tcpci *tcpci, struct tcpci_data *data,
+ bool enable);
+};
+
+struct tcpci *tcpci_register_port(struct device *dev, struct tcpci_data *data);
+void tcpci_unregister_port(struct tcpci *tcpci);
+int tcpci_irq(struct tcpci *tcpci);
+
#endif /* __LINUX_USB_TCPCI_H */