1 // SPDX-License-Identifier: GPL-2.0
3  * Driver for Microchip 48L640 64 Kb SPI Serial EERAM
23 #include <linux/spi/flash.h>
24 #include <linux/spi/spi.h>
33 	struct spi_device	*spi;  member
60 static int mchp48l640_mkcmd(struct mchp48l640_flash *flash, u8 cmd, loff_t addr, char *buf)  in mchp48l640_mkcmd()  argument
69 static int mchp48l640_read_status(struct mchp48l640_flash *flash, int *status)  in mchp48l640_read_status()  argument
76 	mutex_lock(&flash->lock);  in mchp48l640_read_status()
77 	ret = spi_write_then_read(flash->spi, &cmd[0], 1, &cmd[1], 1);  in mchp48l640_read_status()
78 	mutex_unlock(&flash->lock);  in mchp48l640_read_status()
81 	dev_dbg(&flash->spi->dev, "read status ret: %d status: %x", ret, *status);  in mchp48l640_read_status()
86 static int mchp48l640_waitforbit(struct mchp48l640_flash *flash, int bit, bool set)  in mchp48l640_waitforbit()  argument
93 		ret = mchp48l640_read_status(flash, &status);  in mchp48l640_waitforbit()
94 		dev_dbg(&flash->spi->dev, "read status ret: %d bit: %x %sset status: %x",  in mchp48l640_waitforbit()
110 	dev_err(&flash->spi->dev, "Timeout waiting for bit %x %s set in status register.",  in mchp48l640_waitforbit()
112 	return -ETIMEDOUT;  in mchp48l640_waitforbit()
115 static int mchp48l640_write_prepare(struct mchp48l640_flash *flash, bool enable)  in mchp48l640_write_prepare()  argument
125 	mutex_lock(&flash->lock);  in mchp48l640_write_prepare()
126 	ret = spi_write(flash->spi, cmd, 1);  in mchp48l640_write_prepare()
127 	mutex_unlock(&flash->lock);  in mchp48l640_write_prepare()
130 		dev_err(&flash->spi->dev, "write %sable failed ret: %d",  in mchp48l640_write_prepare()
133 	dev_dbg(&flash->spi->dev, "write %sable success ret: %d",  in mchp48l640_write_prepare()
136 		return mchp48l640_waitforbit(flash, MCHP48L640_STATUS_WEL, true);  in mchp48l640_write_prepare()
141 static int mchp48l640_set_mode(struct mchp48l640_flash *flash)  in mchp48l640_set_mode()  argument
146 	ret = mchp48l640_write_prepare(flash, true);  in mchp48l640_set_mode()
153 	mutex_lock(&flash->lock);  in mchp48l640_set_mode()
154 	ret = spi_write(flash->spi, cmd, 2);  in mchp48l640_set_mode()
155 	mutex_unlock(&flash->lock);  in mchp48l640_set_mode()
157 		dev_err(&flash->spi->dev, "Could not set continuous mode ret: %d", ret);  in mchp48l640_set_mode()
159 	return mchp48l640_waitforbit(flash, MCHP48L640_STATUS_PRO, true);  in mchp48l640_set_mode()
162 static int mchp48l640_wait_rdy(struct mchp48l640_flash *flash)  in mchp48l640_wait_rdy()  argument
164 	return mchp48l640_waitforbit(flash, MCHP48L640_STATUS_RDY, false);  in mchp48l640_wait_rdy()
170 	struct mchp48l640_flash *flash = to_mchp48l640_flash(mtd);  in mchp48l640_write_page()  local
177 		return -ENOMEM;  in mchp48l640_write_page()
179 	ret = mchp48l640_wait_rdy(flash);  in mchp48l640_write_page()
183 	ret = mchp48l640_write_prepare(flash, true);  in mchp48l640_write_page()
187 	mutex_lock(&flash->lock);  in mchp48l640_write_page()
188 	cmdlen = mchp48l640_mkcmd(flash, MCHP48L640_CMD_WRITE, to, cmd);  in mchp48l640_write_page()
190 	ret = spi_write(flash->spi, cmd, cmdlen + len);  in mchp48l640_write_page()
191 	mutex_unlock(&flash->lock);  in mchp48l640_write_page()
197 	ret = mchp48l640_waitforbit(flash, MCHP48L640_STATUS_WEL, false);  in mchp48l640_write_page()
205 	dev_err(&flash->spi->dev, "write fail with: %d", ret);  in mchp48l640_write_page()
212 	struct mchp48l640_flash *flash = to_mchp48l640_flash(mtd);  in mchp48l640_write()  local
217 	size_t page_sz = flash->caps->page_size;  in mchp48l640_write()
224 		ws = min((len - wlen), page_sz);  in mchp48l640_write()
238 	struct mchp48l640_flash *flash = to_mchp48l640_flash(mtd);  in mchp48l640_read_page()  local
245 		return -ENOMEM;  in mchp48l640_read_page()
247 	ret = mchp48l640_wait_rdy(flash);  in mchp48l640_read_page()
251 	mutex_lock(&flash->lock);  in mchp48l640_read_page()
252 	cmdlen = mchp48l640_mkcmd(flash, MCHP48L640_CMD_READ, from, cmd);  in mchp48l640_read_page()
253 	ret = spi_write_then_read(flash->spi, cmd, cmdlen, buf, len);  in mchp48l640_read_page()
254 	mutex_unlock(&flash->lock);  in mchp48l640_read_page()
263 	dev_err(&flash->spi->dev, "read fail with: %d", ret);  in mchp48l640_read_page()
270 	struct mchp48l640_flash *flash = to_mchp48l640_flash(mtd);  in mchp48l640_read()  local
275 	size_t page_sz = flash->caps->page_size;  in mchp48l640_read()
282 		ws = min((len - wlen), page_sz);  in mchp48l640_read()
298 static int mchp48l640_probe(struct spi_device *spi)  in mchp48l640_probe()  argument
300 	struct mchp48l640_flash *flash;  in mchp48l640_probe()  local
305 	flash = devm_kzalloc(&spi->dev, sizeof(*flash), GFP_KERNEL);  in mchp48l640_probe()
306 	if (!flash)  in mchp48l640_probe()
307 		return -ENOMEM;  in mchp48l640_probe()
309 	flash->spi = spi;  in mchp48l640_probe()
310 	mutex_init(&flash->lock);  in mchp48l640_probe()
311 	spi_set_drvdata(spi, flash);  in mchp48l640_probe()
313 	err = mchp48l640_read_status(flash, &status);  in mchp48l640_probe()
317 	err = mchp48l640_set_mode(flash);  in mchp48l640_probe()
321 	data = dev_get_platdata(&spi->dev);  in mchp48l640_probe()
323 	flash->caps = of_device_get_match_data(&spi->dev);  in mchp48l640_probe()
324 	if (!flash->caps)  in mchp48l640_probe()
325 		flash->caps = &mchp48l640_caps;  in mchp48l640_probe()
327 	mtd_set_of_node(&flash->mtd, spi->dev.of_node);  in mchp48l640_probe()
328 	flash->mtd.dev.parent	= &spi->dev;  in mchp48l640_probe()
329 	flash->mtd.type		= MTD_RAM;  in mchp48l640_probe()
330 	flash->mtd.flags	= MTD_CAP_RAM;  in mchp48l640_probe()
331 	flash->mtd.writesize	= flash->caps->page_size;  in mchp48l640_probe()
332 	flash->mtd.size		= flash->caps->size;  in mchp48l640_probe()
333 	flash->mtd._read	= mchp48l640_read;  in mchp48l640_probe()
334 	flash->mtd._write	= mchp48l640_write;  in mchp48l640_probe()
336 	err = mtd_device_register(&flash->mtd, data ? data->parts : NULL,  in mchp48l640_probe()
337 				  data ? data->nr_parts : 0);  in mchp48l640_probe()
344 static void mchp48l640_remove(struct spi_device *spi)  in mchp48l640_remove()  argument
346 	struct mchp48l640_flash *flash = spi_get_drvdata(spi);  in mchp48l640_remove()  local
348 	WARN_ON(mtd_device_unregister(&flash->mtd));  in mchp48l640_remove()
367 MODULE_DEVICE_TABLE(spi, mchp48l640_spi_ids);
381 MODULE_DESCRIPTION("MTD SPI driver for Microchip 48l640 EERAM chips");
384 MODULE_ALIAS("spi:mchp48l640");