2  * Driver for the TWSI (i2c) controller found on the Marvell
8  * SPDX-License-Identifier:	GPL-2.0+
12 #include <i2c.h>
33 #include <asm/arch/i2c.h>
44 #include <asm/arch/i2c.h>
84 	/* Number of the device (determined from cell-index property) */
86 	/* The I2C slave address for the device */
88 	/* The configured I2C speed in Hz */
96  * enum mvtwsi_ctrl_register_fields - Bit masks for flags in the control
108 	/* I2C enable */
115  * On sun6i and newer, IFLG is a write-clear bit, which is cleared by writing 1;
126  * enum mvstwsi_status_values - Possible values of I2C controller's status
130  * non-10-bit-address devices are specified.
158  * enum mvstwsi_ack_flags - Determine whether a read byte should be
169  * calc_tick() - Calculate the duration of a clock cycle from the I2C speed
184  * twsi_get_base() - Get controller register base for specified adapter
191 	switch (adap->hwadapnr) {  in twsi_get_base()
217 		printf("Missing mvtwsi controller %d base\n", adap->hwadapnr);  in twsi_get_base()
226  * enum mvtwsi_error_class - types of I2C errors
236  * mvtwsi_error() - Build I2C return code from error information
239  * error into a return code. These error codes are returned from I2C API
257  * twsi_wait() - Wait for I2C bus interrupt flag and check status, or time out.
259  * @return Zero if status is as expected, or a non-zero code if either a time
269 		control = readl(&twsi->control);  in twsi_wait()
271 			status = readl(&twsi->status);  in twsi_wait()
280 	} while (timeout--);  in twsi_wait()
281 	status = readl(&twsi->status);  in twsi_wait()
287  * twsi_start() - Assert a START condition on the bus.
289  * This function is used in both single I2C transactions and inside
290  * back-to-back transactions (repeated starts).
293  * @expected_status:	The I2C bus status expected to be asserted after the
295  * @tick:		The duration of a clock cycle at the current I2C speed.
296  * @return Zero if status is as expected, or a non-zero code if either a time
304 	       MVTWSI_CONTROL_CLEAR_IFLG, &twsi->control);  in twsi_start()
310  * twsi_send() - Send a byte on the I2C bus.
316  * @expected_status:	The I2C bus status expected to be asserted after the
318  * @tick:		The duration of a clock cycle at the current I2C speed.
319  * @return Zero if status is as expected, or a non-zero code if either a time
326 	writel(byte, &twsi->data);  in twsi_send()
327 	/* Clear any pending interrupt -- that will cause sending */  in twsi_send()
329 	       &twsi->control);  in twsi_send()
335  * twsi_recv() - Receive a byte on the I2C bus.
343  * @tick:		The duration of a clock cycle at the current I2C speed.
344  * @return Zero if status is as expected, or a non-zero code if either a time
358 	writel(control | MVTWSI_CONTROL_CLEAR_IFLG, &twsi->control);  in twsi_recv()
363 		*byte = readl(&twsi->data);  in twsi_recv()
368  * twsi_stop() - Assert a STOP condition on the bus.
374  * @tick:	The duration of a clock cycle at the current I2C speed.
375  * @return Zero if the operation succeeded, or a non-zero code if a time out
386 	writel(control | MVTWSI_CONTROL_CLEAR_IFLG, &twsi->control);  in twsi_stop()
389 		stop_status = readl(&twsi->status);  in twsi_stop()
393 	} while (timeout--);  in twsi_stop()
394 	control = readl(&twsi->control);  in twsi_stop()
402  * twsi_calc_freq() - Compute I2C frequency depending on m and n parameters.
406  * @return The I2C frequency corresponding to the passed m and n parameters.
418  * twsi_reset() - Reset the I2C controller.
421  * they must be re-established after the reset.
428 	writel(0, &twsi->soft_reset);  in twsi_reset()
429 	/* Wait 2 ms -- this is what the Marvell LSP does */  in twsi_reset()
434  * __twsi_i2c_set_bus_speed() - Set the speed of the I2C controller.
464 	writel(baud, &twsi->baudrate);  in __twsi_i2c_set_bus_speed()
476  * __twsi_i2c_init() - Initialize the I2C controller.
481  * @slaveadd:		The I2C address to be set for the I2C master.
484  * @return Zero if the operation succeeded, or a non-zero code if a time out
495 	writel(slaveadd, &twsi->slave_address);  in __twsi_i2c_init()
496 	writel(0, &twsi->xtnd_slave_addr);  in __twsi_i2c_init()
506  * i2c_begin() - Start a I2C transaction.
508  * Begin a I2C transaction with a given expected start status and chip address.
509  * A START is asserted, and the address byte is sent to the I2C controller. The
514  * @expected_start_status:	The I2C status the controller is expected to
518  *				I2C speed.
519  * @return Zero if the operation succeeded, or a non-zero code if a time out or
520  *	   unexpected I2C status occurred.
543  * __twsi_i2c_probe_chip() - Probe the given I2C chip address.
545  * This function begins a I2C read transaction, does a dummy read and NAKs; if
550  * @tick:	The duration of a clock cycle at the current I2C speed.
551  * @return Zero if the operation succeeded, or a non-zero code if a time out or
552  *	   unexpected I2C status occurred.
560 	/* Begin i2c read */  in __twsi_i2c_probe_chip()
572  * __twsi_i2c_read() - Read data from a I2C chip.
574  * This function begins a I2C write transaction, and transmits the address
575  * bytes; then begins a I2C read transaction, and receives the data bytes.
589  * @tick:	The duration of a clock cycle at the current I2C speed.
590  * @return Zero if the operation succeeded, or a non-zero code if a time out or
591  *	   unexpected I2C status occurred.
602 		/* Begin i2c write to send the address bytes */  in __twsi_i2c_read()
605 		while ((status == 0) && alen--)  in __twsi_i2c_read()
611 	/* Begin i2c read to receive data bytes */  in __twsi_i2c_read()
616 	while ((status == 0) && length--)  in __twsi_i2c_read()
627  * __twsi_i2c_write() - Send data to a I2C chip.
629  * This function begins a I2C write transaction, and transmits the address
630  * bytes; then begins a new I2C write transaction, and sends the data bytes.
638  * @tick:	The duration of a clock cycle at the current I2C speed.
639  * @return Zero if the operation succeeded, or a non-zero code if a time out or
640  *	   unexpected I2C status occurred.
648 	/* Begin i2c write to send first the address bytes, then the  in __twsi_i2c_write()
652 	while ((status == 0) && (alen-- > 0))  in __twsi_i2c_write()
656 	while ((status == 0) && (length-- > 0))  in __twsi_i2c_write()
764 	return __twsi_i2c_probe_chip(dev->base, chip_addr, dev->tick);
771 	dev->speed = __twsi_i2c_set_bus_speed(dev->base, speed);
772 	dev->tick = calc_tick(dev->speed);
781 	dev->base = devfdt_get_addr_ptr(bus);
783 	if (!dev->base)
784 		return -ENOMEM;
786 	dev->index = fdtdec_get_int(gd->fdt_blob, dev_of_offset(bus),
787 				    "cell-index", -1);
788 	dev->slaveadd = fdtdec_get_int(gd->fdt_blob, dev_of_offset(bus),
789 				       "u-boot,i2c-slave-addr", 0x0);
790 	dev->speed = fdtdec_get_int(gd->fdt_blob, dev_of_offset(bus),
791 				    "clock-frequency", 100000);
800 	__twsi_i2c_init(dev->base, dev->speed, dev->slaveadd, &actual_speed);
801 	dev->speed = actual_speed;
802 	dev->tick = calc_tick(dev->speed);
817 		return -1;
823 	if (dmsg->flags & I2C_M_RD)
824 		return __twsi_i2c_read(dev->base, dmsg->addr, omsg->buf,
825 				       omsg->len, dmsg->buf, dmsg->len,
826 				       dev->tick);
828 		return __twsi_i2c_write(dev->base, dmsg->addr, omsg->buf,
829 					omsg->len, dmsg->buf, dmsg->len,
830 					dev->tick);
840 	{ .compatible = "marvell,mv64xxx-i2c", },
841 	{ .compatible = "marvell,mv78230-i2c", },
842 	{ .compatible = "allwinner,sun6i-a31-i2c", },