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Date: Wed, 14 Feb 2018 06:46:36 -0800
From: Guenter Roeck <linux@...ck-us.net>
To: ShuFanLee <leechu729@...il.com>, heikki.krogerus@...ux.intel.com
Cc: linux-kernel@...r.kernel.org, linux-usb@...r.kernel.org,
cy_huang@...htek.com, shufan_lee@...htek.com
Subject: Re: [PATCH v2] staging: typec: handle vendor defined part and modify
drp toggling flow
On 02/14/2018 04:45 AM, ShuFanLee wrote:
> From: ShuFanLee <shufan_lee@...htek.com>
>
> 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@...htek.com>
> ---
> 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 */
>
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