1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
5  * Copyright (c) 2024 Pierre-Luc Drouin <pldrouin@pldrouin.net>
19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
30  * Vybrid Family Inter-Integrated Circuit (I2C)
63 #define	I2C_IBFD	0x1	/* I2C Bus Frequency Divider Register */
66 #define	 IBCR_IBIE		(1 << 6) /* I-Bus Interrupt Enable. */
78 #define	 IBSR_IBIF		(1 << 1) /* I-Bus Interrupt Flag. */
87 #define	READ1(_sc, _reg) bus_space_read_1(_sc->bst, _sc->bsh, _reg)
88 #define	WRITE1(_sc, _reg, _val)	bus_space_write_1(_sc->bst,\
89 		_sc->bsh, _reg, _val)
93 	device_printf((_sc)->dev, fmt, ##args)
98 		bus_space_write_1(_sc->bst, _sc->bsh, _reg, _val);\
102 		uint32_t ret=bus_space_read_1(_sc->bst, _sc->bsh, _reg);\
126 	{ -1, 0 }
155 	mtx_init(&sc->mutex, device_get_nameunit(dev), "I2C", MTX_DEF);  in vf_i2c_attach_common()
157 	error = bus_alloc_resources(dev, i2c_spec, sc->res);  in vf_i2c_attach_common()
159 		mtx_destroy(&sc->mutex);  in vf_i2c_attach_common()
165 	sc->bst = rman_get_bustag(sc->res[0]);  in vf_i2c_attach_common()
166 	sc->bsh = rman_get_bushandle(sc->res[0]);  in vf_i2c_attach_common()
168 	mtx_lock(&sc->mutex);  in vf_i2c_attach_common()
172 	if (sc->freq == 0) {  in vf_i2c_attach_common()
178 			sc->freq = UINT32_MAX;  in vf_i2c_attach_common()
179 			device_printf(dev, "Using existing bus frequency divider register value (0x%02X).\n", div_reg);  in vf_i2c_attach_common()
181 …device_printf(dev, "Bus frequency divider value appears unset, defaulting to low I2C bus speed.\n"…  in vf_i2c_attach_common()
185 	mtx_unlock(&sc->mutex);  in vf_i2c_attach_common()
187 	sc->iicbus = device_add_child(dev, "iicbus", DEVICE_UNIT_ANY);  in vf_i2c_attach_common()
189 	if (sc->iicbus == NULL) {  in vf_i2c_attach_common()
191 		mtx_destroy(&sc->mutex);  in vf_i2c_attach_common()
192 		bus_release_resources(dev, i2c_spec, sc->res);  in vf_i2c_attach_common()
216 	mtx_lock(&sc->mutex);  in i2c_detach()
218 	if (sc->freq == 0) {  in i2c_detach()
219 		vf_i2c_dbg(sc, "Writing 0x00 to clock divider register\n");  in i2c_detach()
223 	bus_release_resources(dev, i2c_spec, sc->res);  in i2c_detach()
225 	mtx_unlock(&sc->mutex);  in i2c_detach()
227 	mtx_destroy(&sc->mutex);  in i2c_detach()
239 	while (retry --) {  in wait_for_nibb()
258 	while (retry --) {  in wait_for_icf()
298 	mtx_lock(&sc->mutex);  in i2c_repeated_start()
301 		vf_i2c_dbg(sc, "cant i2c repeat start: bus is no longer busy\n");  in i2c_repeated_start()
302 		mtx_unlock(&sc->mutex);  in i2c_repeated_start()
310 	/* Write target address - LSB is R/W bit */  in i2c_repeated_start()
316 		mtx_unlock(&sc->mutex);  in i2c_repeated_start()
321 	mtx_unlock(&sc->mutex);  in i2c_repeated_start()
340 	mtx_lock(&sc->mutex);  in i2c_start()
353 		mtx_unlock(&sc->mutex);  in i2c_start()
364 	/* Write target address - LSB is R/W bit */  in i2c_start()
369 		mtx_unlock(&sc->mutex);  in i2c_start()
373 	mtx_unlock(&sc->mutex);  in i2c_start()
392 	mtx_lock(&sc->mutex);  in i2c_stop()
397 	mtx_unlock(&sc->mutex);  in i2c_stop()
410 	if (sc->freq == UINT32_MAX)  in i2c_get_div_val()
413 	div_reg = vf610_div_table[nitems(vf610_div_table) - 1].reg_val;  in i2c_get_div_val()
415 	if (sc->hwtype == HW_MVF600)  in i2c_get_div_val()
417 	else if (sc->freq == 0)  in i2c_get_div_val()
418 		div_reg = vf610_div_table[nitems(vf610_div_table) - 1].reg_val;  in i2c_get_div_val()
423 		error = clk_get_freq(sc->clock, &clk_freq);  in i2c_get_div_val()
426 					"Using default divider.\n");  in i2c_get_div_val()
427 			div_reg = vf610_div_table[nitems(vf610_div_table) - 1].reg_val;  in i2c_get_div_val()
430 			for (i = 0; i < nitems(vf610_div_table) - 1; i++)  in i2c_get_div_val()
431 				if ((clk_freq / vf610_div_table[i].div) <= sc->freq)  in i2c_get_div_val()
437 	vf_i2c_dbg(sc, "Writing 0x%02X to clock divider register\n", div_reg);  in i2c_get_div_val()
451 	mtx_lock(&sc->mutex);  in i2c_reset()
459 	mtx_unlock(&sc->mutex);  in i2c_reset()
476 	mtx_lock(&sc->mutex);  in i2c_read()
490 				mtx_unlock(&sc->mutex);  in i2c_read()
495 				if (*read == len - 2) {  in i2c_read()
496 					/* NO ACK on last byte */  in i2c_read()
499 				} else if (*read == len - 1) {  in i2c_read()
509 	mtx_unlock(&sc->mutex);  in i2c_read()
526 	mtx_lock(&sc->mutex);  in i2c_write()
532 			mtx_unlock(&sc->mutex);  in i2c_write()
536 		if (!tx_acked(sc) && (*sent  = (len - 2)) ){  in i2c_write()
537 			mtx_unlock(&sc->mutex);  in i2c_write()
538 			vf_i2c_dbg(sc, "no ACK on %d write\n", *sent);  in i2c_write()
544 	mtx_unlock(&sc->mutex);  in i2c_write()