1 // SPDX-License-Identifier: GPL-2.0-or-later
3 #include "i2c-viai2c-common.h"
5 int viai2c_wait_bus_not_busy(struct viai2c *i2c)  in viai2c_wait_bus_not_busy()  argument
10 	while (!(readw(i2c->base + VIAI2C_REG_CSR) & VIAI2C_CSR_READY_MASK)) {  in viai2c_wait_bus_not_busy()
12 			dev_warn(i2c->dev, "timeout waiting for bus ready\n");  in viai2c_wait_bus_not_busy()
13 			return -EBUSY;  in viai2c_wait_bus_not_busy()
18 	return 0;  in viai2c_wait_bus_not_busy()
22 static int viai2c_write(struct viai2c *i2c, struct i2c_msg *pmsg, int last)  in viai2c_write()  argument
24 	u16 val, tcr_val = i2c->tcr;  in viai2c_write()
26 	i2c->last = last;  in viai2c_write()
28 	if (pmsg->len == 0) {  in viai2c_write()
31 		 * start at -1 and break out early from the loop  in viai2c_write()
33 		i2c->xfered_len = -1;  in viai2c_write()
34 		writew(0, i2c->base + VIAI2C_REG_CDR);  in viai2c_write()
36 		writew(pmsg->buf[0] & 0xFF, i2c->base + VIAI2C_REG_CDR);  in viai2c_write()
39 	if (i2c->platform == VIAI2C_PLAT_WMT && !(pmsg->flags & I2C_M_NOSTART)) {  in viai2c_write()
40 		val = readw(i2c->base + VIAI2C_REG_CR);  in viai2c_write()
43 		writew(val, i2c->base + VIAI2C_REG_CR);  in viai2c_write()
46 	reinit_completion(&i2c->complete);  in viai2c_write()
48 	tcr_val |= pmsg->addr & VIAI2C_TCR_ADDR_MASK;  in viai2c_write()
50 	writew(tcr_val, i2c->base + VIAI2C_REG_TCR);  in viai2c_write()
52 	if (i2c->platform == VIAI2C_PLAT_WMT && pmsg->flags & I2C_M_NOSTART) {  in viai2c_write()
53 		val = readw(i2c->base + VIAI2C_REG_CR);  in viai2c_write()
55 		writew(val, i2c->base + VIAI2C_REG_CR);  in viai2c_write()
58 	if (!wait_for_completion_timeout(&i2c->complete, VIAI2C_TIMEOUT))  in viai2c_write()
59 		return -ETIMEDOUT;  in viai2c_write()
61 	return i2c->ret;  in viai2c_write()
64 static int viai2c_read(struct viai2c *i2c, struct i2c_msg *pmsg, bool first)  in viai2c_read()  argument
66 	u16 val, tcr_val = i2c->tcr;  in viai2c_read()
68 	val = readw(i2c->base + VIAI2C_REG_CR);  in viai2c_read()
71 	if (i2c->platform == VIAI2C_PLAT_WMT && !(pmsg->flags & I2C_M_NOSTART))  in viai2c_read()
74 	if (pmsg->len == 1)  in viai2c_read()
77 	writew(val, i2c->base + VIAI2C_REG_CR);  in viai2c_read()
79 	reinit_completion(&i2c->complete);  in viai2c_read()
81 	tcr_val |= VIAI2C_TCR_READ | (pmsg->addr & VIAI2C_TCR_ADDR_MASK);  in viai2c_read()
83 	writew(tcr_val, i2c->base + VIAI2C_REG_TCR);  in viai2c_read()
85 	if ((i2c->platform == VIAI2C_PLAT_WMT && (pmsg->flags & I2C_M_NOSTART)) ||  in viai2c_read()
86 	    (i2c->platform == VIAI2C_PLAT_ZHAOXIN && !first)) {  in viai2c_read()
87 		val = readw(i2c->base + VIAI2C_REG_CR);  in viai2c_read()
89 		writew(val, i2c->base + VIAI2C_REG_CR);  in viai2c_read()
92 	if (!wait_for_completion_timeout(&i2c->complete, VIAI2C_TIMEOUT))  in viai2c_read()
93 		return -ETIMEDOUT;  in viai2c_read()
95 	return i2c->ret;  in viai2c_read()
102 	int ret = 0;  in viai2c_xfer()
103 	struct viai2c *i2c = i2c_get_adapdata(adap);  in viai2c_xfer()  local
105 	i2c->mode = VIAI2C_BYTE_MODE;  in viai2c_xfer()
106 	for (i = 0; ret >= 0 && i < num; i++) {  in viai2c_xfer()
108 		if (i2c->platform == VIAI2C_PLAT_WMT && !(pmsg->flags & I2C_M_NOSTART)) {  in viai2c_xfer()
109 			ret = viai2c_wait_bus_not_busy(i2c);  in viai2c_xfer()
110 			if (ret < 0)  in viai2c_xfer()
114 		i2c->msg = pmsg;  in viai2c_xfer()
115 		i2c->xfered_len = 0;  in viai2c_xfer()
117 		if (pmsg->flags & I2C_M_RD)  in viai2c_xfer()
118 			ret = viai2c_read(i2c, pmsg, i == 0);  in viai2c_xfer()
120 			ret = viai2c_write(i2c, pmsg, (i + 1) == num);  in viai2c_xfer()
123 	return (ret < 0) ? ret : i;  in viai2c_xfer()
132  *  0: there is still data that needs to be transferred
133  *  -EIO: error occurred
135 int viai2c_irq_xfer(struct viai2c *i2c)  in viai2c_irq_xfer()  argument
138 	struct i2c_msg *msg = i2c->msg;  in viai2c_irq_xfer()
139 	u8 read = msg->flags & I2C_M_RD;  in viai2c_irq_xfer()
140 	void __iomem *base = i2c->base;  in viai2c_irq_xfer()
143 		msg->buf[i2c->xfered_len] = readw(base + VIAI2C_REG_CDR) >> 8;  in viai2c_irq_xfer()
146 		if (i2c->xfered_len == msg->len - 2)  in viai2c_irq_xfer()
152 			return -EIO;  in viai2c_irq_xfer()
155 		if (msg->len == 0) {  in viai2c_irq_xfer()
161 		if ((i2c->xfered_len + 1) == msg->len) {  in viai2c_irq_xfer()
162 			if (i2c->platform == VIAI2C_PLAT_WMT && !i2c->last)  in viai2c_irq_xfer()
164 			else if (i2c->platform == VIAI2C_PLAT_ZHAOXIN && i2c->last)  in viai2c_irq_xfer()
167 			writew(msg->buf[i2c->xfered_len + 1] & 0xFF, base + VIAI2C_REG_CDR);  in viai2c_irq_xfer()
172 	i2c->xfered_len++;  in viai2c_irq_xfer()
174 	return i2c->xfered_len == msg->len;  in viai2c_irq_xfer()
180 	struct viai2c *i2c;  in viai2c_init()  local
182 	i2c = devm_kzalloc(&pdev->dev, sizeof(*i2c), GFP_KERNEL);  in viai2c_init()
183 	if (!i2c)  in viai2c_init()
184 		return -ENOMEM;  in viai2c_init()
186 	i2c->base = devm_platform_get_and_ioremap_resource(pdev, 0, NULL);  in viai2c_init()
187 	if (IS_ERR(i2c->base))  in viai2c_init()
188 		return PTR_ERR(i2c->base);  in viai2c_init()
190 	i2c->platform = plat;  in viai2c_init()
192 	i2c->dev = &pdev->dev;  in viai2c_init()
193 	init_completion(&i2c->complete);  in viai2c_init()
194 	platform_set_drvdata(pdev, i2c);  in viai2c_init()
196 	*pi2c = i2c;  in viai2c_init()
197 	return 0;  in viai2c_init()
201 MODULE_DESCRIPTION("Via/Wondermedia/Zhaoxin I2C controller core");