diff mbox series

[v4,2/2] usb: typec: ucsi: add support for Cypress CCGx

Message ID 1535665130-25111-2-git-send-email-ajayg@nvidia.com
State Superseded
Headers show
Series [v4,1/2] i2c: buses: add i2c bus driver for NVIDIA GPU | expand

Commit Message

Ajay Gupta Aug. 30, 2018, 9:38 p.m. UTC 
Latest NVIDIA GPU cards have a Cypress CCGx Type-C controller
over I2C interface.

This UCSI I2C driver uses I2C bus driver interface for communicating
with Type-C controller.

Signed-off-by: Ajay Gupta <ajayg@nvidia.com>
---
Changes from v1 -> v2
	Fixed identation in drivers/usb/typec/ucsi/Kconfig
Changes from v2 -> v3
	Fixed most of comments from Heikki
	Rename ucsi_i2c_ccg.c -> ucsi_ccg.c
Changes from v3 -> v4
	Fixed comments from Andy

 drivers/usb/typec/ucsi/Kconfig    |  10 +
 drivers/usb/typec/ucsi/Makefile   |   2 +
 drivers/usb/typec/ucsi/ucsi_ccg.c | 393 ++++++++++++++++++++++++++++++++++++++
 3 files changed, 405 insertions(+)
 create mode 100644 drivers/usb/typec/ucsi/ucsi_ccg.c

Comments

Andy Shevchenko Aug. 31, 2018, 6:51 a.m. UTC | #1 
On Fri, Aug 31, 2018 at 12:41 AM Ajay Gupta <ajayg@nvidia.com> wrote:

> Latest NVIDIA GPU cards have a Cypress CCGx Type-C controller
> over I2C interface.
>
> This UCSI I2C driver uses I2C bus driver interface for communicating
> with Type-C controller.

> Changes from v3 -> v4
>         Fixed comments from Andy

Unfortunatelly not all comments was addressed, see below.

> +               if (err == ARRAY_SIZE(msgs)) {
> +                       err = 0;
> +               } else if (err >= 0) {
> +                       dev_err(dev, "i2c_transfer failed, err %d\n", err);
> +                       return -EIO;
> +               }

Shouldn't be simple
if (err < 0) {
 ...
 return err;
}

?

> +       if (err == ARRAY_SIZE(msgs)) {
> +               err = 0;
> +       } else if (err >= 0) {
> +               dev_err(dev, "i2c_transfer failed, err %d\n", err);
> +               return -EIO;
> +       }

Ditto.

> +       struct device *dev = uc->dev;
> +       u8 data[64];
> +       int err;

> +       unsigned int count = 10;

Move this line upper a bit.

> +       unsigned char buf[3] = {
> +               CCGX_I2C_RAB_INTR_REG & 0xff, CCGX_I2C_RAB_INTR_REG >> 8, 0x0};

This should follow the style you applied earlier in the same file.

Also, & 0xff is redundant (better just to use >> 0).

> +       struct ucsi_ccg *uc = container_of(ppm,
> +               struct ucsi_ccg, ppm);

One line?

> +static int ucsi_ccg_cmd(struct ucsi_ppm *ppm, struct ucsi_control *ctrl)
> +{
> +       struct ucsi_ccg *uc = container_of(ppm, struct ucsi_ccg, ppm);

> +       int err = 0;

Redundant assignment.

> +
> +       ppm->data->ctrl.raw_cmd = ctrl->raw_cmd;
> +       err = ucsi_ccg_send_data(uc);
> +
> +       return err;
> +}

> +static int ucsi_ccg_probe(struct i2c_client *client,
> +                         const struct i2c_device_id *id)

One line?

> +static const struct i2c_device_id ucsi_ccg_device_id[] = {
> +       {"ccgx-ucsi", 0},

> +       {},

Terminator better w/o comma.

> +};
> +MODULE_DEVICE_TABLE(i2c, ucsi_ccg_device_id);
Ajay Gupta Aug. 31, 2018, 8:41 p.m. UTC | #2 
Hi Andy,
> > Latest NVIDIA GPU cards have a Cypress CCGx Type-C controller over I2C
> > interface.
> >
> > This UCSI I2C driver uses I2C bus driver interface for communicating
> > with Type-C controller.
> 
> > Changes from v3 -> v4
> >         Fixed comments from Andy
> 
> Unfortunatelly not all comments was addressed, see below.
> 
> > +               if (err == ARRAY_SIZE(msgs)) {
> > +                       err = 0;
> > +               } else if (err >= 0) {
> > +                       dev_err(dev, "i2c_transfer failed, err %d\n", err);
> > +                       return -EIO;
> > +               }
> 
> Shouldn't be simple
> if (err < 0) {
>  ...
>  return err;
> }
> 
> ?
Ok, will fix
> 
> > +       if (err == ARRAY_SIZE(msgs)) {
> > +               err = 0;
> > +       } else if (err >= 0) {
> > +               dev_err(dev, "i2c_transfer failed, err %d\n", err);
> > +               return -EIO;
> > +       }
> 
> Ditto.
ok
> 
> > +       struct device *dev = uc->dev;
> > +       u8 data[64];
> > +       int err;
> 
> > +       unsigned int count = 10;
> 
> Move this line upper a bit.
ok
> 
> > +       unsigned char buf[3] = {
> > +               CCGX_I2C_RAB_INTR_REG & 0xff, CCGX_I2C_RAB_INTR_REG >>
> > + 8, 0x0};
> 
> This should follow the style you applied earlier in the same file.
> 
> Also, & 0xff is redundant (better just to use >> 0).
Ok, even ">> 0" will be redundant so will just drop  "& 0xff".

> > +       struct ucsi_ccg *uc = container_of(ppm,
> > +               struct ucsi_ccg, ppm);
> 
> One line?
ok
> 
> > +static int ucsi_ccg_cmd(struct ucsi_ppm *ppm, struct ucsi_control
> > +*ctrl) {
> > +       struct ucsi_ccg *uc = container_of(ppm, struct ucsi_ccg, ppm);
> 
> > +       int err = 0;
> 
> Redundant assignment.
ok
> 
> > +
> > +       ppm->data->ctrl.raw_cmd = ctrl->raw_cmd;
> > +       err = ucsi_ccg_send_data(uc);
> > +
> > +       return err;
> > +}
> 
> > +static int ucsi_ccg_probe(struct i2c_client *client,
> > +                         const struct i2c_device_id *id)
> 
> One line?
It crosses column width of 80. It takes total 85.

> 
> > +static const struct i2c_device_id ucsi_ccg_device_id[] = {
> > +       {"ccgx-ucsi", 0},
> 
> > +       {},
> 
> Terminator better w/o comma.
Ok.
> 
> > +};
> > +MODULE_DEVICE_TABLE(i2c, ucsi_ccg_device_id);
> 
Thanks
Ajay

--
nvpublic
--
> --
> With Best Regards,
> Andy Shevchenko
diff mbox series

Patch

diff --git a/drivers/usb/typec/ucsi/Kconfig b/drivers/usb/typec/ucsi/Kconfig
index e36d6c7..7811888 100644
--- a/drivers/usb/typec/ucsi/Kconfig
+++ b/drivers/usb/typec/ucsi/Kconfig
@@ -23,6 +23,16 @@  config TYPEC_UCSI
 
 if TYPEC_UCSI
 
+config UCSI_CCG
+	tristate "UCSI Interface Driver for Cypress CCGx"
+	depends on I2C
+	help
+	  This driver enables UCSI support on platforms that expose a
+	  Cypress CCGx Type-C controller over I2C interface.
+
+	  To compile the driver as a module, choose M here: the module will be
+	  called ucsi_ccg.
+
 config UCSI_ACPI
 	tristate "UCSI ACPI Interface Driver"
 	depends on ACPI
diff --git a/drivers/usb/typec/ucsi/Makefile b/drivers/usb/typec/ucsi/Makefile
index 7afbea5..2f4900b 100644
--- a/drivers/usb/typec/ucsi/Makefile
+++ b/drivers/usb/typec/ucsi/Makefile
@@ -8,3 +8,5 @@  typec_ucsi-y			:= ucsi.o
 typec_ucsi-$(CONFIG_TRACING)	+= trace.o
 
 obj-$(CONFIG_UCSI_ACPI)		+= ucsi_acpi.o
+
+obj-$(CONFIG_UCSI_CCG)		+= ucsi_ccg.o
diff --git a/drivers/usb/typec/ucsi/ucsi_ccg.c b/drivers/usb/typec/ucsi/ucsi_ccg.c
new file mode 100644
index 0000000..68efefa
--- /dev/null
+++ b/drivers/usb/typec/ucsi/ucsi_ccg.c
@@ -0,0 +1,393 @@ 
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * UCSI driver for Cypress CCGx Type-C controller
+ *
+ * Copyright (C) 2017-2018 NVIDIA Corporation. All rights reserved.
+ * Author: Ajay Gupta <ajayg@nvidia.com>
+ *
+ * Some code borrowed from drivers/usb/typec/ucsi/ucsi_acpi.c
+ */
+#include <linux/acpi.h>
+#include <linux/delay.h>
+#include <linux/i2c.h>
+#include <linux/module.h>
+#include <linux/pci.h>
+#include <linux/platform_device.h>
+#include <asm/unaligned.h>
+#include "ucsi.h"
+
+struct ucsi_ccg {
+	struct device *dev;
+	struct ucsi *ucsi;
+	struct ucsi_ppm ppm;
+	struct i2c_client *client;
+	int irq;
+};
+
+#define CCGX_I2C_RAB_DEVICE_MODE			0x00
+#define CCGX_I2C_RAB_READ_SILICON_ID			0x2
+#define CCGX_I2C_RAB_INTR_REG				0x06
+#define CCGX_I2C_RAB_FW1_VERSION			0x28
+#define CCGX_I2C_RAB_FW2_VERSION			0x20
+#define CCGX_I2C_RAB_UCSI_CONTROL			0x39
+#define CCGX_I2C_RAB_UCSI_CONTROL_START			BIT(0)
+#define CCGX_I2C_RAB_UCSI_CONTROL_STOP			BIT(1)
+#define CCGX_I2C_RAB_RESPONSE_REG			0x7E
+#define CCGX_I2C_RAB_UCSI_DATA_BLOCK			0xf000
+
+static int ccg_read(struct ucsi_ccg *uc, u16 rab, u8 *data, u32 len)
+{
+	struct device *dev = uc->dev;
+	struct i2c_client *client = uc->client;
+	unsigned char buf[2];
+	struct i2c_msg msgs[] = {
+		{
+			.addr	= client->addr,
+			.flags  = 0x0,
+			.len	= 0x2,
+			.buf	= buf,
+		},
+		{
+			.addr	= client->addr,
+			.flags  = I2C_M_RD,
+			.buf	= data,
+		},
+	};
+	u32 rlen, rem_len = len;
+	int err = -EIO;
+
+	while (rem_len > 0) {
+		msgs[1].buf = &data[len - rem_len];
+		rlen = min_t(u16, rem_len, 4);
+		msgs[1].len = rlen;
+		put_unaligned_le16(rab, buf);
+		err = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs));
+		if (err == ARRAY_SIZE(msgs)) {
+			err = 0;
+		} else if (err >= 0) {
+			dev_err(dev, "i2c_transfer failed, err %d\n", err);
+			return -EIO;
+		}
+		rab += rlen;
+		rem_len -= rlen;
+	}
+
+	return err;
+}
+
+static int ccg_write(struct ucsi_ccg *uc, u16 rab, u8 *data, u32 len)
+{
+	struct device *dev = uc->dev;
+	struct i2c_client *client = uc->client;
+	unsigned char buf[2];
+	struct i2c_msg msgs[] = {
+		{
+			.addr	= client->addr,
+			.flags  = 0x0,
+			.len	= 0x2,
+			.buf	= buf,
+		},
+		{
+			.addr	= client->addr,
+			.flags  = 0x0,
+			.buf	= data,
+			.len	= len,
+		},
+		{
+			.addr	= client->addr,
+			.flags  = I2C_M_STOP,
+		},
+	};
+	int err;
+
+	put_unaligned_le16(rab, buf);
+	err = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs));
+	if (err == ARRAY_SIZE(msgs)) {
+		err = 0;
+	} else if (err >= 0) {
+		dev_err(dev, "i2c_transfer failed, err %d\n", err);
+		return -EIO;
+	}
+
+	return err;
+}
+
+static int ucsi_ccg_init(struct ucsi_ccg *uc)
+{
+	struct device *dev = uc->dev;
+	u8 data[64];
+	int err;
+	unsigned int count = 10;
+
+	/*
+	 * Selectively issue device reset
+	 * - if RESPONSE register is RESET_COMPLETE, do not issue device reset
+	 *   (will cause usb device disconnect / reconnect)
+	 * - if RESPONSE register is not RESET_COMPLETE, issue device reset
+	 *   (causes PPC to resync device connect state by re-issuing
+	 *   set mux command)
+	 */
+	data[0] = 0x00;
+	data[1] = 0x00;
+
+	err = ccg_read(uc, CCGX_I2C_RAB_RESPONSE_REG, data, 0x2);
+	if (err < 0) {
+		dev_err(dev, "ccg_read failed, err %d\n", err);
+		return -EIO;
+	}
+
+	memset(data, 0, sizeof(data));
+	err = ccg_read(uc, CCGX_I2C_RAB_DEVICE_MODE, data, sizeof(data));
+	if (err < 0) {
+		dev_err(dev, "ccg_read failed, err %d\n", err);
+		return -EIO;
+	}
+
+	dev_info(dev, "Silicon id %2ph", data + CCGX_I2C_RAB_READ_SILICON_ID);
+	dev_info(dev, "FW1 version %8ph\n", data + CCGX_I2C_RAB_FW1_VERSION);
+	dev_info(dev, "FW2 version %8ph\n", data + CCGX_I2C_RAB_FW2_VERSION);
+
+	data[0] = 0x0;
+	data[1] = 0x0;
+	err = ccg_read(uc, CCGX_I2C_RAB_RESPONSE_REG, data, 0x2);
+	if (err < 0) {
+		dev_err(dev, "ccg_read failed, err %d\n", err);
+		return -EIO;
+	}
+
+	data[0] = CCGX_I2C_RAB_UCSI_CONTROL_STOP;
+	err = ccg_write(uc, CCGX_I2C_RAB_UCSI_CONTROL, data, 0x1);
+	if (err < 0) {
+		dev_err(dev, "ccg_write failed, err %d\n", err);
+		return -EIO;
+	}
+
+	data[0] = CCGX_I2C_RAB_UCSI_CONTROL_START;
+	err = ccg_write(uc, CCGX_I2C_RAB_UCSI_CONTROL, data, 0x1);
+	if (err < 0) {
+		dev_err(dev, "ccg_write failed, err %d\n", err);
+		return -EIO;
+	}
+
+	/*
+	 * Flush CCGx RESPONSE queue by acking interrupts
+	 * - above ucsi control register write will push response
+	 * which must be flushed
+	 * - affects f/w update which reads response register
+	 */
+	data[0] = 0xff;
+	do {
+		err = ccg_write(uc, CCGX_I2C_RAB_INTR_REG, data, 0x1);
+		if (err < 0) {
+			dev_err(dev, "ccg_write failed, err %d\n", err);
+			return -EIO;
+		}
+
+		usleep_range(10000, 11000);
+
+		err = ccg_read(uc, CCGX_I2C_RAB_INTR_REG, data, 0x1);
+		if (err < 0) {
+			dev_err(dev, "ccg_read failed, err %d\n", err);
+			return -EIO;
+		}
+	} while ((data[0] != 0x00) && count--);
+
+	return 0;
+}
+
+static int ucsi_ccg_send_data(struct ucsi_ccg *uc)
+{
+	int err;
+	unsigned char buf[4] = {
+		0x20, CCGX_I2C_RAB_UCSI_DATA_BLOCK >> 8,
+		0x8, CCGX_I2C_RAB_UCSI_DATA_BLOCK >> 8,
+	};
+	unsigned char buf1[16];
+	unsigned char buf2[8];
+
+	memcpy(buf1, ((const void *)uc->ppm.data) + 0x20, sizeof(buf1));
+	memcpy(buf2, ((const void *)uc->ppm.data) + 0x8, sizeof(buf2));
+
+	err = ccg_write(uc, *(u16 *)buf, buf1, sizeof(buf1));
+	if (err < 0) {
+		dev_err(uc->dev, "ccg_write failed, err %d\n", err);
+		return -EIO;
+	}
+
+	err = ccg_write(uc, *(u16 *)(buf + 2), buf2, sizeof(buf2));
+	if (err < 0) {
+		dev_err(uc->dev, "ccg_write failed, err %d\n", err);
+		return -EIO;
+	}
+
+	return err;
+}
+
+static int ucsi_ccg_recv_data(struct ucsi_ccg *uc)
+{
+	u8 *ppm = (u8 *)uc->ppm.data;
+	int err;
+	unsigned char buf[6] = {
+		0x0, CCGX_I2C_RAB_UCSI_DATA_BLOCK >> 8,
+		0x4, CCGX_I2C_RAB_UCSI_DATA_BLOCK >> 8,
+		0x10, CCGX_I2C_RAB_UCSI_DATA_BLOCK >> 8,
+	};
+
+	err = ccg_read(uc, *(u16 *)buf, ppm, 0x2);
+	if (err < 0) {
+		dev_err(uc->dev, "ccg_read failed, err %d\n", err);
+		return -EIO;
+	}
+
+	err = ccg_read(uc, *(u16 *)(buf + 2), ppm + 0x4, 0x4);
+	if (err < 0) {
+		dev_err(uc->dev, "ccg_read failed, err %d\n", err);
+		return -EIO;
+	}
+
+	err = ccg_read(uc, *(u16 *)(buf + 4), ppm + 0x10, 0x10);
+	if (err < 0) {
+		dev_err(uc->dev, "ccg_read failed, err %d\n", err);
+		return -EIO;
+	}
+
+	return err;
+}
+
+static int ucsi_ccg_ack_interrupt(struct ucsi_ccg *uc)
+{
+	int err;
+	unsigned char buf[3] = {
+		CCGX_I2C_RAB_INTR_REG & 0xff, CCGX_I2C_RAB_INTR_REG >> 8, 0x0};
+
+	err = ccg_read(uc, *(u16 *)buf, &buf[2], 0x1);
+	if (err < 0) {
+		dev_err(uc->dev, "ccg_read failed, err %d\n", err);
+		return -EIO;
+	}
+
+	err = ccg_write(uc, *(u16 *)buf, &buf[2], 0x1);
+	if (err < 0) {
+		dev_err(uc->dev, "ccg_read failed, err %d\n", err);
+		return -EIO;
+	}
+
+	return err;
+}
+
+static int ucsi_ccg_sync(struct ucsi_ppm *ppm)
+{
+	struct ucsi_ccg *uc = container_of(ppm,
+		struct ucsi_ccg, ppm);
+	int err;
+
+	err = ucsi_ccg_recv_data(uc);
+	if (err < 0) {
+		dev_err(uc->dev, "ucsi_ccg_recv_data() err %d\n", err);
+		return 0;
+	}
+
+	/* ack interrupt to allow next command to run */
+	err = ucsi_ccg_ack_interrupt(uc);
+	if (err < 0)
+		dev_err(uc->dev, "ucsi_ccg_ack_interrupt() err %d\n", err);
+
+	return 0;
+}
+
+static int ucsi_ccg_cmd(struct ucsi_ppm *ppm, struct ucsi_control *ctrl)
+{
+	struct ucsi_ccg *uc = container_of(ppm, struct ucsi_ccg, ppm);
+	int err = 0;
+
+	ppm->data->ctrl.raw_cmd = ctrl->raw_cmd;
+	err = ucsi_ccg_send_data(uc);
+
+	return err;
+}
+
+static irqreturn_t ccg_irq_handler(int irq, void *data)
+{
+	struct ucsi_ccg *uc = data;
+
+	ucsi_notify(uc->ucsi);
+
+	return IRQ_HANDLED;
+}
+
+static int ucsi_ccg_probe(struct i2c_client *client,
+			  const struct i2c_device_id *id)
+{
+	struct device *dev = &client->dev;
+	struct ucsi_ccg *uc;
+	int status;
+
+	uc = devm_kzalloc(dev, sizeof(*uc), GFP_KERNEL);
+	if (!uc)
+		return -ENOMEM;
+
+	uc->ppm.data = devm_kzalloc(dev, sizeof(struct ucsi_data), GFP_KERNEL);
+	if (!uc->ppm.data)
+		return -ENOMEM;
+
+	uc->ppm.cmd = ucsi_ccg_cmd;
+	uc->ppm.sync = ucsi_ccg_sync;
+	uc->dev = dev;
+	uc->client = client;
+
+	/* reset ccg device and initialize ucsi */
+	status = ucsi_ccg_init(uc);
+	if (status < 0) {
+		dev_err(uc->dev, "ucsi_ccg_init failed - %d\n", status);
+		return status;
+	}
+
+	uc->irq = client->irq;
+
+	status = devm_request_threaded_irq(dev, uc->irq, NULL, ccg_irq_handler,
+					   IRQF_ONESHOT | IRQF_TRIGGER_HIGH,
+					   dev_name(dev), uc);
+	if (status < 0) {
+		dev_err(uc->dev, "request_threaded_irq failed - %d\n", status);
+		return status;
+	}
+
+	uc->ucsi = ucsi_register_ppm(dev, &uc->ppm);
+	if (IS_ERR(uc->ucsi)) {
+		dev_err(uc->dev, "ucsi_register_ppm failed\n");
+		return PTR_ERR(uc->ucsi);
+	}
+
+	i2c_set_clientdata(client, uc);
+	return 0;
+}
+
+static int ucsi_ccg_remove(struct i2c_client *client)
+{
+	struct ucsi_ccg *uc = i2c_get_clientdata(client);
+
+	ucsi_unregister_ppm(uc->ucsi);
+
+	return 0;
+}
+
+static const struct i2c_device_id ucsi_ccg_device_id[] = {
+	{"ccgx-ucsi", 0},
+	{},
+};
+MODULE_DEVICE_TABLE(i2c, ucsi_ccg_device_id);
+
+static struct i2c_driver ucsi_ccg_driver = {
+	.driver = {
+		.name = "ucsi_ccg",
+	},
+	.probe = ucsi_ccg_probe,
+	.remove = ucsi_ccg_remove,
+	.id_table = ucsi_ccg_device_id,
+};
+
+module_i2c_driver(ucsi_ccg_driver);
+
+MODULE_AUTHOR("Ajay Gupta <ajayg@nvidia.com>");
+MODULE_DESCRIPTION("UCSI driver for Cypress CCGx Type-C controller");
+MODULE_LICENSE("GPL v2");