1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
6  * Copyright (c) 2017-2018 Panasas
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
60 static int imcsmb_readb(device_t dev, u_char slave, char cmd, char *byte);
61 static int imcsmb_readw(device_t dev, u_char slave, char cmd, short *word);
62 static int imcsmb_writeb(device_t dev, u_char slave, char cmd, char byte);
63 static int imcsmb_writew(device_t dev, u_char slave, char cmd, short word);
66 static int imcsmb_transfer(device_t dev, u_char slave, char cmd, void *data,
72  * which any SMBus slave device drivers will connect to.
87 	sc->dev = dev;  in imcsmb_attach()
88 	sc->imcsmb_pci = device_get_parent(dev);  in imcsmb_attach()
89 	sc->regs = device_get_ivars(dev);  in imcsmb_attach()
92 	sc->smbus = device_add_child(dev, "smbus", DEVICE_UNIT_ANY);  in imcsmb_attach()
93 	if (sc->smbus == NULL) {  in imcsmb_attach()
153 		if (*how != SMB_DONTWAIT) {  in imcsmb_callback()
157 		rc = imcsmb_pci_request_bus(sc->imcsmb_pci);  in imcsmb_callback()
161 		imcsmb_pci_release_bus(sc->imcsmb_pci);  in imcsmb_callback()
180  * @param[in] slave
191 imcsmb_readb(device_t dev, u_char slave, char cmd, char *byte)  in imcsmb_readb()  argument
194 	return (imcsmb_transfer(dev, slave, cmd, byte, FALSE, FALSE));  in imcsmb_readb()
204  * @param[in] slave
215 imcsmb_readw(device_t dev, u_char slave, char cmd, short *word)  in imcsmb_readw()  argument
218 	return (imcsmb_transfer(dev, slave, cmd, word, TRUE, FALSE));  in imcsmb_readw()
228  * @param[in] slave
239 imcsmb_writeb(device_t dev, u_char slave, char cmd, char byte)  in imcsmb_writeb()  argument
242 	return (imcsmb_transfer(dev, slave, cmd, &byte, FALSE, TRUE));  in imcsmb_writeb()
252  * @param[in] slave
263 imcsmb_writew(device_t dev, u_char slave, char cmd, short word)  in imcsmb_writew()  argument
266 	return (imcsmb_transfer(dev, slave, cmd, &word, TRUE, TRUE));  in imcsmb_writew()
277  * @param[in] slave
295 imcsmb_transfer(device_t dev, u_char slave, char cmd, void *data, int word_op,  in imcsmb_transfer()  argument
319 	orig_cntl_val = pci_read_config(sc->imcsmb_pci,  in imcsmb_transfer()
320 	    sc->regs->smb_cntl, 4);  in imcsmb_transfer()
328 	 * the four high bits of the slave address.  in imcsmb_transfer()
331 	cntl_val |= ((uint32_t) slave & 0xf0) << 24;  in imcsmb_transfer()
354 	if (word_op) {  in imcsmb_transfer()
359 	if (write_op) {  in imcsmb_transfer()
363 	/* [26:24] The three non-DTI, non-R/W bits of the slave address. */  in imcsmb_transfer()
364 	cmd_val |= (uint32_t) ((slave & 0xe) << 23);  in imcsmb_transfer()
372 	if (write_op) {  in imcsmb_transfer()
373 		if (word_op) {  in imcsmb_transfer()
382 			 * the temperature sensors are I2C. Thus, byte-swap the  in imcsmb_transfer()
398 	pci_write_config(sc->imcsmb_pci, sc->regs->smb_cntl, cntl_val, 4);  in imcsmb_transfer()
401 	 * We just cleared the auto-poll bit, so we need to make sure the device  in imcsmb_transfer()
405 	for (i = 4; i != 0; i--) {  in imcsmb_transfer()
406 		stat_val = pci_read_config(sc->imcsmb_pci, sc->regs->smb_stat,  in imcsmb_transfer()
408 		if ((stat_val & IMCSMB_STATUS_BUSY_BIT) == 0) {  in imcsmb_transfer()
414 	if (i == 0) {  in imcsmb_transfer()
415 		device_printf(sc->dev,  in imcsmb_transfer()
422 	pci_write_config(sc->imcsmb_pci, sc->regs->smb_cmd, cmd_val, 4);  in imcsmb_transfer()
427 	for (i = 35000; i != 0; i -= 10)  in imcsmb_transfer()
430 		stat_val = pci_read_config(sc->imcsmb_pci, sc->regs->smb_stat,  in imcsmb_transfer()
440 		if (write_op) {  in imcsmb_transfer()
441 			if ((stat_val & IMCSMB_STATUS_WRITE_DATA_DONE) != 0) {  in imcsmb_transfer()
445 			if ((stat_val & IMCSMB_STATUS_READ_DATA_VALID) != 0) {  in imcsmb_transfer()
450 	if (i == 0) {  in imcsmb_transfer()
456 	/* It is generally the case that this bit indicates non-ACK, but it  in imcsmb_transfer()
460 	if ((stat_val & IMCSMB_STATUS_BUS_ERROR_BIT) != 0) {  in imcsmb_transfer()
461 		/* While it is not documented, empirically, SPD page-change  in imcsmb_transfer()
465 		if ((slave & 0xf0) != 0x60) {  in imcsmb_transfer()
472 	if (write_op == 0) {  in imcsmb_transfer()
473 		if (word_op) {  in imcsmb_transfer()
475 			 * above, byte-swap.  in imcsmb_transfer()
492 	pci_write_config(sc->imcsmb_pci, sc->regs->smb_cntl, orig_cntl_val, 4);  in imcsmb_transfer()