1 // SPDX-License-Identifier: GPL-2.0-or-later
5  * Copyright (C) Guenter Roeck <linux@roeck-us.net>
36 	u8			ctrl;  member
50 static int sc18is602_wait_ready(struct sc18is602 *hw, int len)  in sc18is602_wait_ready()  argument
53 	int usecs = 1000000 * len / hw->speed + 1;  in sc18is602_wait_ready()
57 		err = i2c_master_recv(hw->client, dummy, 1);  in sc18is602_wait_ready()
62 	return -ETIMEDOUT;  in sc18is602_wait_ready()
68 	unsigned int len = t->len;  in sc18is602_txrx()  local
71 	if (hw->tlen == 0) {  in sc18is602_txrx()
73 		hw->buffer[0] = 1 << msg->spi->chip_select;  in sc18is602_txrx()
74 		hw->tlen = 1;  in sc18is602_txrx()
75 		hw->rindex = 0;  in sc18is602_txrx()
82 	if (t->tx_buf) {  in sc18is602_txrx()
83 		memcpy(&hw->buffer[hw->tlen], t->tx_buf, len);  in sc18is602_txrx()
84 		hw->tlen += len;  in sc18is602_txrx()
85 		if (t->rx_buf)  in sc18is602_txrx()
88 			hw->rindex = hw->tlen - 1;  in sc18is602_txrx()
89 	} else if (t->rx_buf) {  in sc18is602_txrx()
91 		 * For receive-only transfers we still need to perform a dummy  in sc18is602_txrx()
96 		hw->rindex = hw->tlen - 1;  in sc18is602_txrx()
97 		memset(&hw->buffer[hw->tlen], 0, len);  in sc18is602_txrx()
98 		hw->tlen += len;  in sc18is602_txrx()
102 	if (do_transfer && hw->tlen > 1) {  in sc18is602_txrx()
106 		ret = i2c_master_send(hw->client, hw->buffer, hw->tlen);  in sc18is602_txrx()
109 		if (ret != hw->tlen)  in sc18is602_txrx()
110 			return -EIO;  in sc18is602_txrx()
112 		if (t->rx_buf) {  in sc18is602_txrx()
113 			int rlen = hw->rindex + len;  in sc18is602_txrx()
115 			ret = sc18is602_wait_ready(hw, hw->tlen);  in sc18is602_txrx()
118 			ret = i2c_master_recv(hw->client, hw->buffer, rlen);  in sc18is602_txrx()
122 				return -EIO;  in sc18is602_txrx()
123 			memcpy(t->rx_buf, &hw->buffer[hw->rindex], len);  in sc18is602_txrx()
125 		hw->tlen = 0;  in sc18is602_txrx()
127 	return len;  in sc18is602_txrx()
132 	u8 ctrl = 0;  in sc18is602_setup_transfer()  local
136 		ctrl |= SC18IS602_MODE_CPHA;  in sc18is602_setup_transfer()
138 		ctrl |= SC18IS602_MODE_CPOL;  in sc18is602_setup_transfer()
140 		ctrl |= SC18IS602_MODE_LSB_FIRST;  in sc18is602_setup_transfer()
143 	if (hz >= hw->freq / 4) {  in sc18is602_setup_transfer()
144 		ctrl |= SC18IS602_MODE_CLOCK_DIV_4;  in sc18is602_setup_transfer()
145 		hw->speed = hw->freq / 4;  in sc18is602_setup_transfer()
146 	} else if (hz >= hw->freq / 16) {  in sc18is602_setup_transfer()
147 		ctrl |= SC18IS602_MODE_CLOCK_DIV_16;  in sc18is602_setup_transfer()
148 		hw->speed = hw->freq / 16;  in sc18is602_setup_transfer()
149 	} else if (hz >= hw->freq / 64) {  in sc18is602_setup_transfer()
150 		ctrl |= SC18IS602_MODE_CLOCK_DIV_64;  in sc18is602_setup_transfer()
151 		hw->speed = hw->freq / 64;  in sc18is602_setup_transfer()
153 		ctrl |= SC18IS602_MODE_CLOCK_DIV_128;  in sc18is602_setup_transfer()
154 		hw->speed = hw->freq / 128;  in sc18is602_setup_transfer()
159 	 * value of 0xff for hw->ctrl ensures that the correct mode will be set  in sc18is602_setup_transfer()
162 	if (ctrl == hw->ctrl)  in sc18is602_setup_transfer()
165 	ret = i2c_smbus_write_byte_data(hw->client, 0xf0, ctrl);  in sc18is602_setup_transfer()
169 	hw->ctrl = ctrl;  in sc18is602_setup_transfer()
177 	if (t && t->len + tlen > SC18IS602_BUFSIZ + 1)  in sc18is602_check_transfer()
178 		return -EINVAL;  in sc18is602_check_transfer()
187 	struct spi_device *spi = m->spi;  in sc18is602_transfer_one()
191 	hw->tlen = 0;  in sc18is602_transfer_one()
192 	list_for_each_entry(t, &m->transfers, transfer_list) {  in sc18is602_transfer_one()
195 		status = sc18is602_check_transfer(spi, t, hw->tlen);  in sc18is602_transfer_one()
199 		status = sc18is602_setup_transfer(hw, t->speed_hz, spi->mode);  in sc18is602_transfer_one()
203 		do_transfer = t->cs_change || list_is_last(&t->transfer_list,  in sc18is602_transfer_one()
204 							   &m->transfers);  in sc18is602_transfer_one()
206 		if (t->len) {  in sc18is602_transfer_one()
210 			m->actual_length += status;  in sc18is602_transfer_one()
216 	m->status = status;  in sc18is602_transfer_one()
229 	struct sc18is602 *hw = spi_master_get_devdata(spi->master);  in sc18is602_setup()
232 	if (hw->id == sc18is602 && spi->chip_select == 2)  in sc18is602_setup()
233 		return -ENXIO;  in sc18is602_setup()
241 	struct device *dev = &client->dev;  in sc18is602_probe()
242 	struct device_node *np = dev->of_node;  in sc18is602_probe()
247 	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C |  in sc18is602_probe()
249 		return -EINVAL;  in sc18is602_probe()
253 		return -ENOMEM;  in sc18is602_probe()
259 	hw->reset = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_HIGH);  in sc18is602_probe()
260 	if (IS_ERR(hw->reset))  in sc18is602_probe()
261 		return PTR_ERR(hw->reset);  in sc18is602_probe()
262 	gpiod_set_value_cansleep(hw->reset, 0);  in sc18is602_probe()
264 	hw->master = master;  in sc18is602_probe()
265 	hw->client = client;  in sc18is602_probe()
266 	hw->dev = dev;  in sc18is602_probe()
267 	hw->ctrl = 0xff;  in sc18is602_probe()
269 	if (client->dev.of_node)  in sc18is602_probe()
270 		hw->id = (enum chips)of_device_get_match_data(&client->dev);  in sc18is602_probe()
272 		hw->id = id->driver_data;  in sc18is602_probe()
274 	switch (hw->id) {  in sc18is602_probe()
277 		master->num_chipselect = 4;  in sc18is602_probe()
278 		hw->freq = SC18IS602_CLOCK;  in sc18is602_probe()
281 		master->num_chipselect = 2;  in sc18is602_probe()
283 			hw->freq = pdata->clock_frequency;  in sc18is602_probe()
286 			int len;  in sc18is602_probe()  local
288 			val = of_get_property(np, "clock-frequency", &len);  in sc18is602_probe()
289 			if (val && len >= sizeof(__be32))  in sc18is602_probe()
290 				hw->freq = be32_to_cpup(val);  in sc18is602_probe()
292 		if (!hw->freq)  in sc18is602_probe()
293 			hw->freq = SC18IS602_CLOCK;  in sc18is602_probe()
296 	master->bus_num = np ? -1 : client->adapter->nr;  in sc18is602_probe()
297 	master->mode_bits = SPI_CPHA | SPI_CPOL | SPI_LSB_FIRST;  in sc18is602_probe()
298 	master->bits_per_word_mask = SPI_BPW_MASK(8);  in sc18is602_probe()
299 	master->setup = sc18is602_setup;  in sc18is602_probe()
300 	master->transfer_one_message = sc18is602_transfer_one;  in sc18is602_probe()
301 	master->max_transfer_size = sc18is602_max_transfer_size;  in sc18is602_probe()
302 	master->max_message_size = sc18is602_max_transfer_size;  in sc18is602_probe()
303 	master->dev.of_node = np;  in sc18is602_probe()
304 	master->min_speed_hz = hw->freq / 128;  in sc18is602_probe()
305 	master->max_speed_hz = hw->freq / 4;  in sc18is602_probe()