--- /dev/null
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2020, Google LLC
+ *
+ * MAXIM TCPCI based TCPC driver
+ */
+
+#include <linux/gpio.h>
+#include <linux/gpio/consumer.h>
+#include <linux/interrupt.h>
+#include <linux/i2c.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of_gpio.h>
+#include <linux/regmap.h>
+#include <linux/usb/pd.h>
+#include <linux/usb/tcpm.h>
+#include <linux/usb/typec.h>
+
+#include "tcpci.h"
+
+#define PD_ACTIVITY_TIMEOUT_MS 10000
+
+#define TCPC_VENDOR_ALERT 0x80
+
+#define TCPC_RECEIVE_BUFFER_COUNT_OFFSET 0
+#define TCPC_RECEIVE_BUFFER_FRAME_TYPE_OFFSET 1
+#define TCPC_RECEIVE_BUFFER_RX_BYTE_BUF_OFFSET 2
+
+/*
+ * LongMessage not supported, hence 32 bytes for buf to be read from RECEIVE_BUFFER.
+ * DEVICE_CAPABILITIES_2.LongMessage = 0, the value in READABLE_BYTE_COUNT reg shall be
+ * less than or equal to 31. Since, RECEIVE_BUFFER len = 31 + 1(READABLE_BYTE_COUNT).
+ */
+#define TCPC_RECEIVE_BUFFER_LEN 32
+
+#define MAX_BUCK_BOOST_SID 0x69
+#define MAX_BUCK_BOOST_OP 0xb9
+#define MAX_BUCK_BOOST_OFF 0
+#define MAX_BUCK_BOOST_SOURCE 0xa
+#define MAX_BUCK_BOOST_SINK 0x5
+
+struct max_tcpci_chip {
+ struct tcpci_data data;
+ struct tcpci *tcpci;
+ struct device *dev;
+ struct i2c_client *client;
+ struct tcpm_port *port;
+};
+
+static const struct regmap_range max_tcpci_tcpci_range[] = {
+ regmap_reg_range(0x00, 0x95)
+};
+
+const struct regmap_access_table max_tcpci_tcpci_write_table = {
+ .yes_ranges = max_tcpci_tcpci_range,
+ .n_yes_ranges = ARRAY_SIZE(max_tcpci_tcpci_range),
+};
+
+static const struct regmap_config max_tcpci_regmap_config = {
+ .reg_bits = 8,
+ .val_bits = 8,
+ .max_register = 0x95,
+ .wr_table = &max_tcpci_tcpci_write_table,
+};
+
+static struct max_tcpci_chip *tdata_to_max_tcpci(struct tcpci_data *tdata)
+{
+ return container_of(tdata, struct max_tcpci_chip, data);
+}
+
+static int max_tcpci_read16(struct max_tcpci_chip *chip, unsigned int reg, u16 *val)
+{
+ return regmap_raw_read(chip->data.regmap, reg, val, sizeof(u16));
+}
+
+static int max_tcpci_write16(struct max_tcpci_chip *chip, unsigned int reg, u16 val)
+{
+ return regmap_raw_write(chip->data.regmap, reg, &val, sizeof(u16));
+}
+
+static int max_tcpci_read8(struct max_tcpci_chip *chip, unsigned int reg, u8 *val)
+{
+ return regmap_raw_read(chip->data.regmap, reg, val, sizeof(u8));
+}
+
+static int max_tcpci_write8(struct max_tcpci_chip *chip, unsigned int reg, u8 val)
+{
+ return regmap_raw_write(chip->data.regmap, reg, &val, sizeof(u8));
+}
+
+static void max_tcpci_init_regs(struct max_tcpci_chip *chip)
+{
+ u16 alert_mask = 0;
+ int ret;
+
+ ret = max_tcpci_write16(chip, TCPC_ALERT, 0xffff);
+ if (ret < 0) {
+ dev_err(chip->dev, "Error writing to TCPC_ALERT ret:%d\n", ret);
+ return;
+ }
+
+ ret = max_tcpci_write16(chip, TCPC_VENDOR_ALERT, 0xffff);
+ if (ret < 0) {
+ dev_err(chip->dev, "Error writing to TCPC_VENDOR_ALERT ret:%d\n", ret);
+ return;
+ }
+
+ alert_mask = TCPC_ALERT_TX_SUCCESS | TCPC_ALERT_TX_DISCARDED | TCPC_ALERT_TX_FAILED |
+ TCPC_ALERT_RX_HARD_RST | TCPC_ALERT_RX_STATUS | TCPC_ALERT_CC_STATUS |
+ TCPC_ALERT_VBUS_DISCNCT | TCPC_ALERT_RX_BUF_OVF | TCPC_ALERT_POWER_STATUS;
+
+ ret = max_tcpci_write16(chip, TCPC_ALERT_MASK, alert_mask);
+ if (ret < 0) {
+ dev_err(chip->dev, "Error writing to TCPC_ALERT_MASK ret:%d\n", ret);
+ return;
+ }
+
+ /* Enable vbus voltage monitoring and voltage alerts */
+ ret = max_tcpci_write8(chip, TCPC_POWER_CTRL, 0);
+ if (ret < 0) {
+ dev_err(chip->dev, "Error writing to TCPC_POWER_CTRL ret:%d\n", ret);
+ return;
+ }
+}
+
+static void process_rx(struct max_tcpci_chip *chip, u16 status)
+{
+ struct pd_message msg;
+ u8 count, frame_type, rx_buf[TCPC_RECEIVE_BUFFER_LEN];
+ int ret, payload_index;
+ u8 *rx_buf_ptr;
+
+ /*
+ * READABLE_BYTE_COUNT: Indicates the number of bytes in the RX_BUF_BYTE_x registers
+ * plus one (for the RX_BUF_FRAME_TYPE) Table 4-36.
+ * Read the count and frame type.
+ */
+ ret = regmap_raw_read(chip->data.regmap, TCPC_RX_BYTE_CNT, rx_buf, 2);
+ if (ret < 0) {
+ dev_err(chip->dev, "TCPC_RX_BYTE_CNT read failed ret:%d", ret);
+ return;
+ }
+
+ count = rx_buf[TCPC_RECEIVE_BUFFER_COUNT_OFFSET];
+ frame_type = rx_buf[TCPC_RECEIVE_BUFFER_FRAME_TYPE_OFFSET];
+
+ if (count == 0 || frame_type != TCPC_RX_BUF_FRAME_TYPE_SOP) {
+ max_tcpci_write16(chip, TCPC_ALERT, TCPC_ALERT_RX_STATUS);
+ dev_err(chip->dev, "%s", count == 0 ? "error: count is 0" :
+ "error frame_type is not SOP");
+ return;
+ }
+
+ if (count > sizeof(struct pd_message) || count + 1 > TCPC_RECEIVE_BUFFER_LEN) {
+ dev_err(chip->dev, "Invalid TCPC_RX_BYTE_CNT %d", count);
+ return;
+ }
+
+ /*
+ * Read count + 1 as RX_BUF_BYTE_x is hidden and can only be read through
+ * TCPC_RX_BYTE_CNT
+ */
+ count += 1;
+ ret = regmap_raw_read(chip->data.regmap, TCPC_RX_BYTE_CNT, rx_buf, count);
+ if (ret < 0) {
+ dev_err(chip->dev, "Error: TCPC_RX_BYTE_CNT read failed: %d", ret);
+ return;
+ }
+
+ rx_buf_ptr = rx_buf + TCPC_RECEIVE_BUFFER_RX_BYTE_BUF_OFFSET;
+ msg.header = cpu_to_le16(*(u16 *)rx_buf_ptr);
+ rx_buf_ptr = rx_buf_ptr + sizeof(msg.header);
+ for (payload_index = 0; payload_index < pd_header_cnt_le(msg.header); payload_index++,
+ rx_buf_ptr += sizeof(msg.payload[0]))
+ msg.payload[payload_index] = cpu_to_le32(*(u32 *)rx_buf_ptr);
+
+ /*
+ * Read complete, clear RX status alert bit.
+ * Clear overflow as well if set.
+ */
+ ret = max_tcpci_write16(chip, TCPC_ALERT, status & TCPC_ALERT_RX_BUF_OVF ?
+ TCPC_ALERT_RX_STATUS | TCPC_ALERT_RX_BUF_OVF :
+ TCPC_ALERT_RX_STATUS);
+ if (ret < 0)
+ return;
+
+ tcpm_pd_receive(chip->port, &msg);
+}
+
+static int max_tcpci_set_vbus(struct tcpci *tcpci, struct tcpci_data *tdata, bool source, bool sink)
+{
+ struct max_tcpci_chip *chip = tdata_to_max_tcpci(tdata);
+ u8 buffer_source[2] = {MAX_BUCK_BOOST_OP, MAX_BUCK_BOOST_SOURCE};
+ u8 buffer_sink[2] = {MAX_BUCK_BOOST_OP, MAX_BUCK_BOOST_SINK};
+ u8 buffer_none[2] = {MAX_BUCK_BOOST_OP, MAX_BUCK_BOOST_OFF};
+ struct i2c_client *i2c = chip->client;
+ int ret;
+
+ struct i2c_msg msgs[] = {
+ {
+ .addr = MAX_BUCK_BOOST_SID,
+ .flags = i2c->flags & I2C_M_TEN,
+ .len = 2,
+ .buf = source ? buffer_source : sink ? buffer_sink : buffer_none,
+ },
+ };
+
+ if (source && sink) {
+ dev_err(chip->dev, "Both source and sink set\n");
+ return -EINVAL;
+ }
+
+ ret = i2c_transfer(i2c->adapter, msgs, 1);
+
+ return ret < 0 ? ret : 1;
+}
+
+static void process_power_status(struct max_tcpci_chip *chip)
+{
+ u8 pwr_status;
+ int ret;
+
+ ret = max_tcpci_read8(chip, TCPC_POWER_STATUS, &pwr_status);
+ if (ret < 0)
+ return;
+
+ if (pwr_status == 0xff)
+ max_tcpci_init_regs(chip);
+ else
+ tcpm_vbus_change(chip->port);
+}
+
+static void process_tx(struct max_tcpci_chip *chip, u16 status)
+{
+ if (status & TCPC_ALERT_TX_SUCCESS)
+ tcpm_pd_transmit_complete(chip->port, TCPC_TX_SUCCESS);
+ else if (status & TCPC_ALERT_TX_DISCARDED)
+ tcpm_pd_transmit_complete(chip->port, TCPC_TX_DISCARDED);
+ else if (status & TCPC_ALERT_TX_FAILED)
+ tcpm_pd_transmit_complete(chip->port, TCPC_TX_FAILED);
+
+ /* Reinit regs as Hard reset sets them to default value */
+ if ((status & TCPC_ALERT_TX_SUCCESS) && (status & TCPC_ALERT_TX_FAILED))
+ max_tcpci_init_regs(chip);
+}
+
+static irqreturn_t _max_tcpci_irq(struct max_tcpci_chip *chip, u16 status)
+{
+ u16 mask;
+ int ret;
+
+ /*
+ * Clear alert status for everything except RX_STATUS, which shouldn't
+ * be cleared until we have successfully retrieved message.
+ */
+ if (status & ~TCPC_ALERT_RX_STATUS) {
+ mask = status & TCPC_ALERT_RX_BUF_OVF ?
+ status & ~(TCPC_ALERT_RX_STATUS | TCPC_ALERT_RX_BUF_OVF) :
+ status & ~TCPC_ALERT_RX_STATUS;
+ ret = max_tcpci_write16(chip, TCPC_ALERT, mask);
+ if (ret < 0) {
+ dev_err(chip->dev, "ALERT clear failed\n");
+ return ret;
+ }
+ }
+
+ if (status & TCPC_ALERT_RX_BUF_OVF && !(status & TCPC_ALERT_RX_STATUS)) {
+ ret = max_tcpci_write16(chip, TCPC_ALERT, (TCPC_ALERT_RX_STATUS |
+ TCPC_ALERT_RX_BUF_OVF));
+ if (ret < 0) {
+ dev_err(chip->dev, "ALERT clear failed\n");
+ return ret;
+ }
+ }
+
+ if (status & TCPC_ALERT_RX_STATUS)
+ process_rx(chip, status);
+
+ if (status & TCPC_ALERT_VBUS_DISCNCT)
+ tcpm_vbus_change(chip->port);
+
+ if (status & TCPC_ALERT_CC_STATUS)
+ tcpm_cc_change(chip->port);
+
+ if (status & TCPC_ALERT_POWER_STATUS)
+ process_power_status(chip);
+
+ if (status & TCPC_ALERT_RX_HARD_RST) {
+ tcpm_pd_hard_reset(chip->port);
+ max_tcpci_init_regs(chip);
+ }
+
+ if (status & TCPC_ALERT_TX_SUCCESS || status & TCPC_ALERT_TX_DISCARDED || status &
+ TCPC_ALERT_TX_FAILED)
+ process_tx(chip, status);
+
+ return IRQ_HANDLED;
+}
+
+static irqreturn_t max_tcpci_irq(int irq, void *dev_id)
+{
+ struct max_tcpci_chip *chip = dev_id;
+ u16 status;
+ irqreturn_t irq_return;
+ int ret;
+
+ if (!chip->port)
+ return IRQ_HANDLED;
+
+ ret = max_tcpci_read16(chip, TCPC_ALERT, &status);
+ if (ret < 0) {
+ dev_err(chip->dev, "ALERT read failed\n");
+ return ret;
+ }
+ while (status) {
+ irq_return = _max_tcpci_irq(chip, status);
+ /* Do not return if the ALERT is already set. */
+ ret = max_tcpci_read16(chip, TCPC_ALERT, &status);
+ if (ret < 0)
+ break;
+ }
+
+ return irq_return;
+}
+
+static irqreturn_t max_tcpci_isr(int irq, void *dev_id)
+{
+ struct max_tcpci_chip *chip = dev_id;
+
+ pm_wakeup_event(chip->dev, PD_ACTIVITY_TIMEOUT_MS);
+
+ if (!chip->port)
+ return IRQ_HANDLED;
+
+ return IRQ_WAKE_THREAD;
+}
+
+static int max_tcpci_init_alert(struct max_tcpci_chip *chip, struct i2c_client *client)
+{
+ int ret;
+
+ ret = devm_request_threaded_irq(chip->dev, client->irq, max_tcpci_isr, max_tcpci_irq,
+ (IRQF_TRIGGER_LOW | IRQF_ONESHOT), dev_name(chip->dev),
+ chip);
+
+ if (ret < 0)
+ return ret;
+
+ enable_irq_wake(client->irq);
+ return 0;
+}
+
+static int max_tcpci_start_toggling(struct tcpci *tcpci, struct tcpci_data *tdata,
+ enum typec_cc_status cc)
+{
+ struct max_tcpci_chip *chip = tdata_to_max_tcpci(tdata);
+
+ max_tcpci_init_regs(chip);
+
+ return 0;
+}
+
+static int tcpci_init(struct tcpci *tcpci, struct tcpci_data *data)
+{
+ /*
+ * Generic TCPCI overwrites the regs once this driver initializes
+ * them. Prevent this by returning -1.
+ */
+ return -1;
+}
+
+static int max_tcpci_probe(struct i2c_client *client, const struct i2c_device_id *i2c_id)
+{
+ int ret;
+ struct max_tcpci_chip *chip;
+ u8 power_status;
+
+ chip = devm_kzalloc(&client->dev, sizeof(*chip), GFP_KERNEL);
+ if (!chip)
+ return -ENOMEM;
+
+ chip->client = client;
+ chip->data.regmap = devm_regmap_init_i2c(client, &max_tcpci_regmap_config);
+ if (IS_ERR(chip->data.regmap)) {
+ dev_err(&client->dev, "Regmap init failed\n");
+ return PTR_ERR(chip->data.regmap);
+ }
+
+ chip->dev = &client->dev;
+ i2c_set_clientdata(client, chip);
+
+ ret = max_tcpci_read8(chip, TCPC_POWER_STATUS, &power_status);
+ if (ret < 0)
+ return ret;
+
+ /* Chip level tcpci callbacks */
+ chip->data.set_vbus = max_tcpci_set_vbus;
+ chip->data.start_drp_toggling = max_tcpci_start_toggling;
+ chip->data.TX_BUF_BYTE_x_hidden = true;
+ chip->data.init = tcpci_init;
+
+ max_tcpci_init_regs(chip);
+ chip->tcpci = tcpci_register_port(chip->dev, &chip->data);
+ if (IS_ERR_OR_NULL(chip->tcpci)) {
+ dev_err(&client->dev, "TCPCI port registration failed");
+ ret = PTR_ERR(chip->tcpci);
+ return PTR_ERR(chip->tcpci);
+ }
+ chip->port = tcpci_get_tcpm_port(chip->tcpci);
+ ret = max_tcpci_init_alert(chip, client);
+ if (ret < 0)
+ goto unreg_port;
+
+ device_init_wakeup(chip->dev, true);
+ return 0;
+
+unreg_port:
+ tcpci_unregister_port(chip->tcpci);
+
+ return ret;
+}
+
+static int max_tcpci_remove(struct i2c_client *client)
+{
+ struct max_tcpci_chip *chip = i2c_get_clientdata(client);
+
+ if (!IS_ERR_OR_NULL(chip->tcpci))
+ tcpci_unregister_port(chip->tcpci);
+
+ return 0;
+}
+
+static const struct i2c_device_id max_tcpci_id[] = {
+ { "maxtcpc", 0 },
+ { }
+};
+MODULE_DEVICE_TABLE(i2c, max_tcpci_id);
+
+#ifdef CONFIG_OF
+static const struct of_device_id max_tcpci_of_match[] = {
+ { .compatible = "maxim,tcpc", },
+ {},
+};
+MODULE_DEVICE_TABLE(of, max_tcpci_of_match);
+#endif
+
+static struct i2c_driver max_tcpci_i2c_driver = {
+ .driver = {
+ .name = "maxtcpc",
+ .of_match_table = of_match_ptr(max_tcpci_of_match),
+ },
+ .probe = max_tcpci_probe,
+ .remove = max_tcpci_remove,
+ .id_table = max_tcpci_id,
+};
+module_i2c_driver(max_tcpci_i2c_driver);
+
+MODULE_AUTHOR("Badhri Jagan Sridharan <badhri@google.com>");
+MODULE_DESCRIPTION("Maxim TCPCI based USB Type-C Port Controller Interface Driver");
+MODULE_LICENSE("GPL v2");
projects / platform / kernel / linux-starfive.git / commitdiff