drivers: i2c: introduce new Telink B91 I2C driver

I2C driver basic support for Telink B91 platform.

Signed-off-by: Yuriy Vynnychek <yura.vynnychek@telink-semi.com>

CODEOWNERS

@@ -355,6 +355,7 @@
 /drivers/usb/                             @jfischer-no
 /drivers/usb/device/usb_dc_stm32.c        @ydamigos @loicpoulain
 /drivers/video/                           @loicpoulain
+/drivers/i2c/*b91*                        @yurvyn
 /drivers/i2c/i2c_ll_stm32*                @ydamigos
 /drivers/i2c/i2c_rv32m1_lpi2c*            @henrikbrixandersen
 /drivers/i2c/*sam0*                       @Sizurka

drivers/i2c/CMakeLists.txt

@@ -5,6 +5,7 @@ zephyr_library()
 zephyr_library_sources(i2c_common.c)
 zephyr_library_sources_ifdef(CONFIG_I2C_SHELL		i2c_shell.c)
 zephyr_library_sources_ifdef(CONFIG_I2C_BITBANG		i2c_bitbang.c)
+zephyr_library_sources_ifdef(CONFIG_I2C_TELINK_B91		i2c_b91.c)
 zephyr_library_sources_ifdef(CONFIG_I2C_CC13XX_CC26XX		i2c_cc13xx_cc26xx.c)
 zephyr_library_sources_ifdef(CONFIG_I2C_CC32XX		i2c_cc32xx.c)
 zephyr_library_sources_ifdef(CONFIG_I2C_ESP32		i2c_esp32.c)

drivers/i2c/Kconfig

@@ -24,6 +24,7 @@ config I2C_SHELL
 
 # Include these first so that any properties (e.g. defaults) below can be
 # overridden (by defining symbols in multiple locations)
+source "drivers/i2c/Kconfig.b91"
 source "drivers/i2c/Kconfig.cc13xx_cc26xx"
 source "drivers/i2c/Kconfig.dw"
 source "drivers/i2c/Kconfig.esp32"

drivers/i2c/Kconfig.b91

@@ -0,0 +1,8 @@
+# Copyright (c) 2021 Telink Semiconductor
+# SPDX-License-Identifier: Apache-2.0
+
+config I2C_TELINK_B91
+	bool "Telink Semiconductor B91 I2C driver"
+	depends on SOC_RISCV_TELINK_B91
+	help
+	  Enables Telink B91 I2C driver.

drivers/i2c/i2c_b91.c

@@ -0,0 +1,188 @@
+/*
+ * Copyright (c) 2021 Telink Semiconductor
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#define DT_DRV_COMPAT telink_b91_i2c
+
+#include "i2c.h"
+#include "clock.h"
+
+#include <logging/log.h>
+LOG_MODULE_REGISTER(i2c_telink);
+
+#include <drivers/i2c.h>
+#include "i2c-priv.h"
+#include <drivers/pinmux.h>
+#include <dt-bindings/pinctrl/b91-pinctrl.h>
+
+/* I2C configuration structure */
+struct i2c_b91_cfg {
+	uint32_t bitrate;
+	const uint32_t *pinctrl_list;
+	size_t pinctrl_list_size;
+};
+
+/* I2C data structure */
+struct i2c_b91_data {
+	struct k_sem mutex;
+};
+
+/* API implementation: configure */
+static int i2c_b91_configure(const struct device *dev, uint32_t dev_config)
+{
+	ARG_UNUSED(dev);
+
+	uint32_t i2c_speed = 0u;
+
+	/* check address size */
+	if (dev_config & I2C_ADDR_10_BITS) {
+		LOG_ERR("10-bits address is not supported");
+		return -ENOTSUP;
+	}
+
+	/* check I2C Master/Slave configuration */
+	if (!(dev_config & I2C_MODE_MASTER)) {
+		LOG_ERR("I2C slave is not implemented");
+		return -ENOTSUP;
+	}
+
+	/* check i2c speed */
+	switch (I2C_SPEED_GET(dev_config)) {
+	case I2C_SPEED_STANDARD:
+		i2c_speed = 100000u;
+		break;
+
+	case I2C_SPEED_FAST:
+		i2c_speed = 400000U;
+		break;
+
+	case I2C_SPEED_FAST_PLUS:
+	case I2C_SPEED_HIGH:
+	case I2C_SPEED_ULTRA:
+	default:
+		LOG_ERR("Unsupported I2C speed requested");
+		return -ENOTSUP;
+	}
+
+	/* init i2c */
+	i2c_master_init();
+	i2c_set_master_clk((unsigned char)(sys_clk.pclk * 1000 * 1000 / (4 * i2c_speed)));
+
+	return 0;
+}
+
+/* API implementation: transfer */
+static int i2c_b91_transfer(const struct device *dev,
+			    struct i2c_msg *msgs,
+			    uint8_t num_msgs,
+			    uint16_t addr)
+{
+	int status = 0;
+	uint8_t send_stop = 0;
+	struct i2c_b91_data *data = dev->data;
+
+	/* get the mutex */
+	k_sem_take(&data->mutex, K_FOREVER);
+
+	/* loop through all messages */
+	for (int i = 0; i < num_msgs; i++) {
+		/* check addr size */
+		if (msgs[i].flags & I2C_MSG_ADDR_10_BITS) {
+			LOG_ERR("10-bits address is not supported");
+			k_sem_give(&data->mutex);
+			return -ENOTSUP;
+		}
+
+		/* config stop bit */
+		send_stop = msgs[i].flags & I2C_MSG_STOP ? 1 : 0;
+		i2c_master_send_stop(send_stop);
+
+		/* transfer data */
+		if (msgs[i].flags & I2C_MSG_READ) {
+			status = i2c_master_read(addr, msgs[i].buf, msgs[i].len);
+		} else {
+			status = i2c_master_write(addr, msgs[i].buf, msgs[i].len);
+		}
+
+		/* check status */
+		if (!status) {
+			LOG_ERR("Failed to transfer I2C messages\n");
+			k_sem_give(&data->mutex);
+			return -EIO;
+		}
+	}
+
+	/* release the mutex */
+	k_sem_give(&data->mutex);
+
+	return 0;
+};
+
+/* API implementation: init */
+static int i2c_b91_init(const struct device *dev)
+{
+	int status = 0;
+	const struct device *pinmux;
+	const struct i2c_b91_cfg *cfg = dev->config;
+	struct i2c_b91_data *data = dev->data;
+	uint32_t dev_config = (I2C_MODE_MASTER | i2c_map_dt_bitrate(cfg->bitrate));
+
+	/* init mutex */
+	k_sem_init(&data->mutex, 1, 1);
+
+	/* config i2c on startup */
+	status = i2c_b91_configure(dev, dev_config);
+	if (status != 0) {
+		LOG_ERR("Failed to configure I2C on init");
+		return status;
+	}
+
+	/* get pinmux driver */
+	pinmux = DEVICE_DT_GET(DT_NODELABEL(pinmux));
+	if (!device_is_ready(pinmux)) {
+		return -ENODEV;
+	}
+
+	/* config pins */
+	for (int i = 0; i < cfg->pinctrl_list_size; i++) {
+		pinmux_pin_set(pinmux, B91_PINMUX_GET_PIN(cfg->pinctrl_list[i]),
+			       B91_PINMUX_GET_FUNC(cfg->pinctrl_list[i]));
+	}
+
+	return 0;
+}
+
+/* I2C driver APIs structure */
+static const struct i2c_driver_api i2c_b91_api = {
+	.configure = i2c_b91_configure,
+	.transfer = i2c_b91_transfer,
+};
+
+BUILD_ASSERT(DT_NUM_INST_STATUS_OKAY(DT_DRV_COMPAT) <= 1,
+	     "unsupported I2C instance");
+
+/* I2C driver registration */
+#define I2C_B91_INIT(inst)					  \
+								  \
+	static const uint32_t i2c_pins_##inst[] =		  \
+		B91_PINMUX_DT_INST_GET_ARRAY(inst, 0);		  \
+								  \
+	static struct i2c_b91_data i2c_b91_data_##inst;		  \
+								  \
+	static struct i2c_b91_cfg i2c_b91_cfg_##inst = {	  \
+		.bitrate = DT_INST_PROP(inst, clock_frequency),	  \
+		.pinctrl_list_size = ARRAY_SIZE(i2c_pins_##inst), \
+		.pinctrl_list = i2c_pins_##inst			  \
+	};							  \
+								  \
+	DEVICE_DT_INST_DEFINE(inst, i2c_b91_init,		  \
+			      NULL,				  \
+			      &i2c_b91_data_##inst,		  \
+			      &i2c_b91_cfg_##inst,		  \
+			      POST_KERNEL,			  \
+			      CONFIG_KERNEL_INIT_PRIORITY_DEVICE, \
+			      &i2c_b91_api);
+
+DT_INST_FOREACH_STATUS_OKAY(I2C_B91_INIT)