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v5.4
  1// SPDX-License-Identifier: GPL-2.0-or-later
  2/*
  3 * Analog Devices AD-FMCOMMS1-EBZ board I2C-SPI bridge driver
  4 *
  5 * Copyright 2012 Analog Devices Inc.
  6 * Author: Lars-Peter Clausen <lars@metafoo.de>
  7 */
  8
  9#include <linux/kernel.h>
 10#include <linux/module.h>
 11#include <linux/delay.h>
 12#include <linux/i2c.h>
 13#include <linux/spi/spi.h>
 14#include <asm/unaligned.h>
 15
 16#define SPI_XCOMM_SETTINGS_LEN_OFFSET		10
 17#define SPI_XCOMM_SETTINGS_3WIRE		BIT(6)
 18#define SPI_XCOMM_SETTINGS_CS_HIGH		BIT(5)
 19#define SPI_XCOMM_SETTINGS_SAMPLE_END		BIT(4)
 20#define SPI_XCOMM_SETTINGS_CPHA			BIT(3)
 21#define SPI_XCOMM_SETTINGS_CPOL			BIT(2)
 22#define SPI_XCOMM_SETTINGS_CLOCK_DIV_MASK	0x3
 23#define SPI_XCOMM_SETTINGS_CLOCK_DIV_64		0x2
 24#define SPI_XCOMM_SETTINGS_CLOCK_DIV_16		0x1
 25#define SPI_XCOMM_SETTINGS_CLOCK_DIV_4		0x0
 26
 27#define SPI_XCOMM_CMD_UPDATE_CONFIG	0x03
 28#define SPI_XCOMM_CMD_WRITE		0x04
 29
 30#define SPI_XCOMM_CLOCK 48000000
 31
 32struct spi_xcomm {
 33	struct i2c_client *i2c;
 34
 35	uint16_t settings;
 36	uint16_t chipselect;
 37
 38	unsigned int current_speed;
 39
 40	uint8_t buf[63];
 41};
 42
 43static int spi_xcomm_sync_config(struct spi_xcomm *spi_xcomm, unsigned int len)
 44{
 45	uint16_t settings;
 46	uint8_t *buf = spi_xcomm->buf;
 47
 48	settings = spi_xcomm->settings;
 49	settings |= len << SPI_XCOMM_SETTINGS_LEN_OFFSET;
 50
 51	buf[0] = SPI_XCOMM_CMD_UPDATE_CONFIG;
 52	put_unaligned_be16(settings, &buf[1]);
 53	put_unaligned_be16(spi_xcomm->chipselect, &buf[3]);
 54
 55	return i2c_master_send(spi_xcomm->i2c, buf, 5);
 56}
 57
 58static void spi_xcomm_chipselect(struct spi_xcomm *spi_xcomm,
 59	struct spi_device *spi, int is_active)
 60{
 61	unsigned long cs = spi->chip_select;
 62	uint16_t chipselect = spi_xcomm->chipselect;
 63
 64	if (is_active)
 65		chipselect |= BIT(cs);
 66	else
 67		chipselect &= ~BIT(cs);
 68
 69	spi_xcomm->chipselect = chipselect;
 70}
 71
 72static int spi_xcomm_setup_transfer(struct spi_xcomm *spi_xcomm,
 73	struct spi_device *spi, struct spi_transfer *t, unsigned int *settings)
 74{
 75	if (t->len > 62)
 76		return -EINVAL;
 77
 78	if (t->speed_hz != spi_xcomm->current_speed) {
 79		unsigned int divider;
 80
 81		divider = DIV_ROUND_UP(SPI_XCOMM_CLOCK, t->speed_hz);
 82		if (divider >= 64)
 83			*settings |= SPI_XCOMM_SETTINGS_CLOCK_DIV_64;
 84		else if (divider >= 16)
 85			*settings |= SPI_XCOMM_SETTINGS_CLOCK_DIV_16;
 86		else
 87			*settings |= SPI_XCOMM_SETTINGS_CLOCK_DIV_4;
 88
 89		spi_xcomm->current_speed = t->speed_hz;
 90	}
 91
 92	if (spi->mode & SPI_CPOL)
 93		*settings |= SPI_XCOMM_SETTINGS_CPOL;
 94	else
 95		*settings &= ~SPI_XCOMM_SETTINGS_CPOL;
 96
 97	if (spi->mode & SPI_CPHA)
 98		*settings &= ~SPI_XCOMM_SETTINGS_CPHA;
 99	else
100		*settings |= SPI_XCOMM_SETTINGS_CPHA;
101
102	if (spi->mode & SPI_3WIRE)
103		*settings |= SPI_XCOMM_SETTINGS_3WIRE;
104	else
105		*settings &= ~SPI_XCOMM_SETTINGS_3WIRE;
106
107	return 0;
108}
109
110static int spi_xcomm_txrx_bufs(struct spi_xcomm *spi_xcomm,
111	struct spi_device *spi, struct spi_transfer *t)
112{
113	int ret;
114
115	if (t->tx_buf) {
116		spi_xcomm->buf[0] = SPI_XCOMM_CMD_WRITE;
117		memcpy(spi_xcomm->buf + 1, t->tx_buf, t->len);
118
119		ret = i2c_master_send(spi_xcomm->i2c, spi_xcomm->buf, t->len + 1);
120		if (ret < 0)
121			return ret;
122		else if (ret != t->len + 1)
123			return -EIO;
124	} else if (t->rx_buf) {
125		ret = i2c_master_recv(spi_xcomm->i2c, t->rx_buf, t->len);
126		if (ret < 0)
127			return ret;
128		else if (ret != t->len)
129			return -EIO;
130	}
131
132	return t->len;
133}
134
135static int spi_xcomm_transfer_one(struct spi_master *master,
136	struct spi_message *msg)
137{
138	struct spi_xcomm *spi_xcomm = spi_master_get_devdata(master);
139	unsigned int settings = spi_xcomm->settings;
140	struct spi_device *spi = msg->spi;
141	unsigned cs_change = 0;
142	struct spi_transfer *t;
143	bool is_first = true;
144	int status = 0;
145	bool is_last;
146
147	spi_xcomm_chipselect(spi_xcomm, spi, true);
148
149	list_for_each_entry(t, &msg->transfers, transfer_list) {
150
151		if (!t->tx_buf && !t->rx_buf && t->len) {
152			status = -EINVAL;
153			break;
154		}
155
156		status = spi_xcomm_setup_transfer(spi_xcomm, spi, t, &settings);
157		if (status < 0)
158			break;
159
160		is_last = list_is_last(&t->transfer_list, &msg->transfers);
161		cs_change = t->cs_change;
162
163		if (cs_change ^ is_last)
164			settings |= BIT(5);
165		else
166			settings &= ~BIT(5);
167
168		if (t->rx_buf) {
169			spi_xcomm->settings = settings;
170			status = spi_xcomm_sync_config(spi_xcomm, t->len);
171			if (status < 0)
172				break;
173		} else if (settings != spi_xcomm->settings || is_first) {
174			spi_xcomm->settings = settings;
175			status = spi_xcomm_sync_config(spi_xcomm, 0);
176			if (status < 0)
177				break;
178		}
179
180		if (t->len) {
181			status = spi_xcomm_txrx_bufs(spi_xcomm, spi, t);
182
183			if (status < 0)
184				break;
185
186			if (status > 0)
187				msg->actual_length += status;
188		}
189		status = 0;
190
191		if (t->delay_usecs)
192			udelay(t->delay_usecs);
193
194		is_first = false;
195	}
196
197	if (status != 0 || !cs_change)
198		spi_xcomm_chipselect(spi_xcomm, spi, false);
199
200	msg->status = status;
201	spi_finalize_current_message(master);
202
203	return status;
204}
205
206static int spi_xcomm_probe(struct i2c_client *i2c,
207	const struct i2c_device_id *id)
208{
209	struct spi_xcomm *spi_xcomm;
210	struct spi_master *master;
211	int ret;
212
213	master = spi_alloc_master(&i2c->dev, sizeof(*spi_xcomm));
214	if (!master)
215		return -ENOMEM;
216
217	spi_xcomm = spi_master_get_devdata(master);
218	spi_xcomm->i2c = i2c;
219
220	master->num_chipselect = 16;
221	master->mode_bits = SPI_CPHA | SPI_CPOL | SPI_3WIRE;
222	master->bits_per_word_mask = SPI_BPW_MASK(8);
223	master->flags = SPI_MASTER_HALF_DUPLEX;
224	master->transfer_one_message = spi_xcomm_transfer_one;
225	master->dev.of_node = i2c->dev.of_node;
226	i2c_set_clientdata(i2c, master);
227
228	ret = devm_spi_register_master(&i2c->dev, master);
229	if (ret < 0)
230		spi_master_put(master);
231
232	return ret;
233}
234
235static const struct i2c_device_id spi_xcomm_ids[] = {
236	{ "spi-xcomm" },
237	{ },
238};
239MODULE_DEVICE_TABLE(i2c, spi_xcomm_ids);
240
241static struct i2c_driver spi_xcomm_driver = {
242	.driver = {
243		.name	= "spi-xcomm",
244	},
245	.id_table	= spi_xcomm_ids,
246	.probe		= spi_xcomm_probe,
247};
248module_i2c_driver(spi_xcomm_driver);
249
250MODULE_LICENSE("GPL");
251MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
252MODULE_DESCRIPTION("Analog Devices AD-FMCOMMS1-EBZ board I2C-SPI bridge driver");
v6.2
  1// SPDX-License-Identifier: GPL-2.0-or-later
  2/*
  3 * Analog Devices AD-FMCOMMS1-EBZ board I2C-SPI bridge driver
  4 *
  5 * Copyright 2012 Analog Devices Inc.
  6 * Author: Lars-Peter Clausen <lars@metafoo.de>
  7 */
  8
  9#include <linux/kernel.h>
 10#include <linux/module.h>
 11#include <linux/delay.h>
 12#include <linux/i2c.h>
 13#include <linux/spi/spi.h>
 14#include <asm/unaligned.h>
 15
 16#define SPI_XCOMM_SETTINGS_LEN_OFFSET		10
 17#define SPI_XCOMM_SETTINGS_3WIRE		BIT(6)
 18#define SPI_XCOMM_SETTINGS_CS_HIGH		BIT(5)
 19#define SPI_XCOMM_SETTINGS_SAMPLE_END		BIT(4)
 20#define SPI_XCOMM_SETTINGS_CPHA			BIT(3)
 21#define SPI_XCOMM_SETTINGS_CPOL			BIT(2)
 22#define SPI_XCOMM_SETTINGS_CLOCK_DIV_MASK	0x3
 23#define SPI_XCOMM_SETTINGS_CLOCK_DIV_64		0x2
 24#define SPI_XCOMM_SETTINGS_CLOCK_DIV_16		0x1
 25#define SPI_XCOMM_SETTINGS_CLOCK_DIV_4		0x0
 26
 27#define SPI_XCOMM_CMD_UPDATE_CONFIG	0x03
 28#define SPI_XCOMM_CMD_WRITE		0x04
 29
 30#define SPI_XCOMM_CLOCK 48000000
 31
 32struct spi_xcomm {
 33	struct i2c_client *i2c;
 34
 35	uint16_t settings;
 36	uint16_t chipselect;
 37
 38	unsigned int current_speed;
 39
 40	uint8_t buf[63];
 41};
 42
 43static int spi_xcomm_sync_config(struct spi_xcomm *spi_xcomm, unsigned int len)
 44{
 45	uint16_t settings;
 46	uint8_t *buf = spi_xcomm->buf;
 47
 48	settings = spi_xcomm->settings;
 49	settings |= len << SPI_XCOMM_SETTINGS_LEN_OFFSET;
 50
 51	buf[0] = SPI_XCOMM_CMD_UPDATE_CONFIG;
 52	put_unaligned_be16(settings, &buf[1]);
 53	put_unaligned_be16(spi_xcomm->chipselect, &buf[3]);
 54
 55	return i2c_master_send(spi_xcomm->i2c, buf, 5);
 56}
 57
 58static void spi_xcomm_chipselect(struct spi_xcomm *spi_xcomm,
 59	struct spi_device *spi, int is_active)
 60{
 61	unsigned long cs = spi->chip_select;
 62	uint16_t chipselect = spi_xcomm->chipselect;
 63
 64	if (is_active)
 65		chipselect |= BIT(cs);
 66	else
 67		chipselect &= ~BIT(cs);
 68
 69	spi_xcomm->chipselect = chipselect;
 70}
 71
 72static int spi_xcomm_setup_transfer(struct spi_xcomm *spi_xcomm,
 73	struct spi_device *spi, struct spi_transfer *t, unsigned int *settings)
 74{
 75	if (t->len > 62)
 76		return -EINVAL;
 77
 78	if (t->speed_hz != spi_xcomm->current_speed) {
 79		unsigned int divider;
 80
 81		divider = DIV_ROUND_UP(SPI_XCOMM_CLOCK, t->speed_hz);
 82		if (divider >= 64)
 83			*settings |= SPI_XCOMM_SETTINGS_CLOCK_DIV_64;
 84		else if (divider >= 16)
 85			*settings |= SPI_XCOMM_SETTINGS_CLOCK_DIV_16;
 86		else
 87			*settings |= SPI_XCOMM_SETTINGS_CLOCK_DIV_4;
 88
 89		spi_xcomm->current_speed = t->speed_hz;
 90	}
 91
 92	if (spi->mode & SPI_CPOL)
 93		*settings |= SPI_XCOMM_SETTINGS_CPOL;
 94	else
 95		*settings &= ~SPI_XCOMM_SETTINGS_CPOL;
 96
 97	if (spi->mode & SPI_CPHA)
 98		*settings &= ~SPI_XCOMM_SETTINGS_CPHA;
 99	else
100		*settings |= SPI_XCOMM_SETTINGS_CPHA;
101
102	if (spi->mode & SPI_3WIRE)
103		*settings |= SPI_XCOMM_SETTINGS_3WIRE;
104	else
105		*settings &= ~SPI_XCOMM_SETTINGS_3WIRE;
106
107	return 0;
108}
109
110static int spi_xcomm_txrx_bufs(struct spi_xcomm *spi_xcomm,
111	struct spi_device *spi, struct spi_transfer *t)
112{
113	int ret;
114
115	if (t->tx_buf) {
116		spi_xcomm->buf[0] = SPI_XCOMM_CMD_WRITE;
117		memcpy(spi_xcomm->buf + 1, t->tx_buf, t->len);
118
119		ret = i2c_master_send(spi_xcomm->i2c, spi_xcomm->buf, t->len + 1);
120		if (ret < 0)
121			return ret;
122		else if (ret != t->len + 1)
123			return -EIO;
124	} else if (t->rx_buf) {
125		ret = i2c_master_recv(spi_xcomm->i2c, t->rx_buf, t->len);
126		if (ret < 0)
127			return ret;
128		else if (ret != t->len)
129			return -EIO;
130	}
131
132	return t->len;
133}
134
135static int spi_xcomm_transfer_one(struct spi_master *master,
136	struct spi_message *msg)
137{
138	struct spi_xcomm *spi_xcomm = spi_master_get_devdata(master);
139	unsigned int settings = spi_xcomm->settings;
140	struct spi_device *spi = msg->spi;
141	unsigned cs_change = 0;
142	struct spi_transfer *t;
143	bool is_first = true;
144	int status = 0;
145	bool is_last;
146
147	spi_xcomm_chipselect(spi_xcomm, spi, true);
148
149	list_for_each_entry(t, &msg->transfers, transfer_list) {
150
151		if (!t->tx_buf && !t->rx_buf && t->len) {
152			status = -EINVAL;
153			break;
154		}
155
156		status = spi_xcomm_setup_transfer(spi_xcomm, spi, t, &settings);
157		if (status < 0)
158			break;
159
160		is_last = list_is_last(&t->transfer_list, &msg->transfers);
161		cs_change = t->cs_change;
162
163		if (cs_change ^ is_last)
164			settings |= BIT(5);
165		else
166			settings &= ~BIT(5);
167
168		if (t->rx_buf) {
169			spi_xcomm->settings = settings;
170			status = spi_xcomm_sync_config(spi_xcomm, t->len);
171			if (status < 0)
172				break;
173		} else if (settings != spi_xcomm->settings || is_first) {
174			spi_xcomm->settings = settings;
175			status = spi_xcomm_sync_config(spi_xcomm, 0);
176			if (status < 0)
177				break;
178		}
179
180		if (t->len) {
181			status = spi_xcomm_txrx_bufs(spi_xcomm, spi, t);
182
183			if (status < 0)
184				break;
185
186			if (status > 0)
187				msg->actual_length += status;
188		}
189		status = 0;
190
191		spi_transfer_delay_exec(t);
 
192
193		is_first = false;
194	}
195
196	if (status != 0 || !cs_change)
197		spi_xcomm_chipselect(spi_xcomm, spi, false);
198
199	msg->status = status;
200	spi_finalize_current_message(master);
201
202	return status;
203}
204
205static int spi_xcomm_probe(struct i2c_client *i2c)
 
206{
207	struct spi_xcomm *spi_xcomm;
208	struct spi_master *master;
209	int ret;
210
211	master = spi_alloc_master(&i2c->dev, sizeof(*spi_xcomm));
212	if (!master)
213		return -ENOMEM;
214
215	spi_xcomm = spi_master_get_devdata(master);
216	spi_xcomm->i2c = i2c;
217
218	master->num_chipselect = 16;
219	master->mode_bits = SPI_CPHA | SPI_CPOL | SPI_3WIRE;
220	master->bits_per_word_mask = SPI_BPW_MASK(8);
221	master->flags = SPI_MASTER_HALF_DUPLEX;
222	master->transfer_one_message = spi_xcomm_transfer_one;
223	master->dev.of_node = i2c->dev.of_node;
224	i2c_set_clientdata(i2c, master);
225
226	ret = devm_spi_register_master(&i2c->dev, master);
227	if (ret < 0)
228		spi_master_put(master);
229
230	return ret;
231}
232
233static const struct i2c_device_id spi_xcomm_ids[] = {
234	{ "spi-xcomm" },
235	{ },
236};
237MODULE_DEVICE_TABLE(i2c, spi_xcomm_ids);
238
239static struct i2c_driver spi_xcomm_driver = {
240	.driver = {
241		.name	= "spi-xcomm",
242	},
243	.id_table	= spi_xcomm_ids,
244	.probe_new	= spi_xcomm_probe,
245};
246module_i2c_driver(spi_xcomm_driver);
247
248MODULE_LICENSE("GPL");
249MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
250MODULE_DESCRIPTION("Analog Devices AD-FMCOMMS1-EBZ board I2C-SPI bridge driver");