3 files changed, 319 insertions, 0 deletions

diff --git a/drivers/usb/typec/ucsi/Kconfig b/drivers/usb/typec/ucsi/Kconfig
index e36d6c73c4a4..78118883f96c 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 7afbea512207..2f4900b26210 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 000000000000..de8a43bdff68
--- /dev/null
+++ b/drivers/usb/typec/ucsi/ucsi_ccg.c
@@ -0,0 +1,307 @@
+// 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;
+};
+
+#define CCGX_RAB_INTR_REG                       0x06
+#define CCGX_RAB_UCSI_CONTROL                   0x39
+#define CCGX_RAB_UCSI_CONTROL_START             BIT(0)
+#define CCGX_RAB_UCSI_CONTROL_STOP              BIT(1)
+#define CCGX_RAB_UCSI_DATA_BLOCK(offset)        (0xf000 | ((offset) & 0xff))
+
+static int ccg_read(struct ucsi_ccg *uc, u16 rab, u8 *data, u32 len)
+{
+        struct i2c_client *client = uc->client;
+        const struct i2c_adapter_quirks *quirks = client->adapter->quirks;
+        unsigned char buf[2];
+        struct i2c_msg msgs[] = {
+                {
+                        .addr   = client->addr,
+                        .flags  = 0x0,
+                        .len    = sizeof(buf),
+                        .buf    = buf,
+                },
+                {
+                        .addr   = client->addr,
+                        .flags  = I2C_M_RD,
+                        .buf    = data,
+                },
+        };
+        u32 rlen, rem_len = len, max_read_len = len;
+        int status;
+
+        /* check any max_read_len limitation on i2c adapter */
+        if (quirks && quirks->max_read_len)
+                max_read_len = quirks->max_read_len;
+
+        while (rem_len > 0) {
+                msgs[1].buf = &data[len - rem_len];
+                rlen = min_t(u16, rem_len, max_read_len);
+                msgs[1].len = rlen;
+                put_unaligned_le16(rab, buf);
+                status = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs));
+                if (status < 0) {
+                        dev_err(uc->dev, "i2c_transfer failed %d\n", status);
+                        return status;
+                }
+                rab += rlen;
+                rem_len -= rlen;
+        }
+
+        return 0;
+}
+
+static int ccg_write(struct ucsi_ccg *uc, u16 rab, u8 *data, u32 len)
+{
+        struct i2c_client *client = uc->client;
+        unsigned char *buf;
+        struct i2c_msg msgs[] = {
+                {
+                        .addr   = client->addr,
+                        .flags  = 0x0,
+                }
+        };
+        int status;
+
+        buf = kzalloc(len + sizeof(rab), GFP_KERNEL);
+        if (!buf)
+                return -ENOMEM;
+
+        put_unaligned_le16(rab, buf);
+        memcpy(buf + sizeof(rab), data, len);
+
+        msgs[0].len = len + sizeof(rab);
+        msgs[0].buf = buf;
+
+        status = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs));
+        if (status < 0) {
+                dev_err(uc->dev, "i2c_transfer failed %d\n", status);
+                kfree(buf);
+                return status;
+        }
+
+        kfree(buf);
+        return 0;
+}
+
+static int ucsi_ccg_init(struct ucsi_ccg *uc)
+{
+        unsigned int count = 10;
+        u8 data;
+        int status;
+
+        data = CCGX_RAB_UCSI_CONTROL_STOP;
+        status = ccg_write(uc, CCGX_RAB_UCSI_CONTROL, &data, sizeof(data));
+        if (status < 0)
+                return status;
+
+        data = CCGX_RAB_UCSI_CONTROL_START;
+        status = ccg_write(uc, CCGX_RAB_UCSI_CONTROL, &data, sizeof(data));
+        if (status < 0)
+                return status;
+
+        /*
+         * Flush CCGx RESPONSE queue by acking interrupts. Above ucsi control
+         * register write will push response which must be cleared.
+         */
+        do {
+                status = ccg_read(uc, CCGX_RAB_INTR_REG, &data, sizeof(data));
+                if (status < 0)
+                        return status;
+
+                if (!data)
+                        return 0;
+
+                status = ccg_write(uc, CCGX_RAB_INTR_REG, &data, sizeof(data));
+                if (status < 0)
+                        return status;
+
+                usleep_range(10000, 11000);
+        } while (--count);
+
+        return -ETIMEDOUT;
+}
+
+static int ucsi_ccg_send_data(struct ucsi_ccg *uc)
+{
+        u8 *ppm = (u8 *)uc->ppm.data;
+        int status;
+        u16 rab;
+
+        rab = CCGX_RAB_UCSI_DATA_BLOCK(offsetof(struct ucsi_data, message_out));
+        status = ccg_write(uc, rab, ppm +
+                           offsetof(struct ucsi_data, message_out),
+                           sizeof(uc->ppm.data->message_out));
+        if (status < 0)
+                return status;
+
+        rab = CCGX_RAB_UCSI_DATA_BLOCK(offsetof(struct ucsi_data, ctrl));
+        return ccg_write(uc, rab, ppm + offsetof(struct ucsi_data, ctrl),
+                         sizeof(uc->ppm.data->ctrl));
+}
+
+static int ucsi_ccg_recv_data(struct ucsi_ccg *uc)
+{
+        u8 *ppm = (u8 *)uc->ppm.data;
+        int status;
+        u16 rab;
+
+        rab = CCGX_RAB_UCSI_DATA_BLOCK(offsetof(struct ucsi_data, cci));
+        status = ccg_read(uc, rab, ppm + offsetof(struct ucsi_data, cci),
+                          sizeof(uc->ppm.data->cci));
+        if (status < 0)
+                return status;
+
+        rab = CCGX_RAB_UCSI_DATA_BLOCK(offsetof(struct ucsi_data, message_in));
+        return ccg_read(uc, rab, ppm + offsetof(struct ucsi_data, message_in),
+                        sizeof(uc->ppm.data->message_in));
+}
+
+static int ucsi_ccg_ack_interrupt(struct ucsi_ccg *uc)
+{
+        int status;
+        unsigned char data;
+
+        status = ccg_read(uc, CCGX_RAB_INTR_REG, &data, sizeof(data));
+        if (status < 0)
+                return status;
+
+        return ccg_write(uc, CCGX_RAB_INTR_REG, &data, sizeof(data));
+}
+
+static int ucsi_ccg_sync(struct ucsi_ppm *ppm)
+{
+        struct ucsi_ccg *uc = container_of(ppm, struct ucsi_ccg, ppm);
+        int status;
+
+        status = ucsi_ccg_recv_data(uc);
+        if (status < 0)
+                return status;
+
+        /* ack interrupt to allow next command to run */
+        return ucsi_ccg_ack_interrupt(uc);
+}
+
+static int ucsi_ccg_cmd(struct ucsi_ppm *ppm, struct ucsi_control *ctrl)
+{
+        struct ucsi_ccg *uc = container_of(ppm, struct ucsi_ccg, ppm);
+
+        ppm->data->ctrl.raw_cmd = ctrl->raw_cmd;
+        return ucsi_ccg_send_data(uc);
+}
+
+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;
+        u16 rab;
+
+        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;
+        }
+
+        status = devm_request_threaded_irq(dev, client->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);
+        }
+
+        rab = CCGX_RAB_UCSI_DATA_BLOCK(offsetof(struct ucsi_data, version));
+        status = ccg_read(uc, rab, (u8 *)(uc->ppm.data) +
+                          offsetof(struct ucsi_data, version),
+                          sizeof(uc->ppm.data->version));
+        if (status < 0) {
+                ucsi_unregister_ppm(uc->ucsi);
+                return status;
+        }
+
+        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");