1 // SPDX-License-Identifier: GPL-2.0-only
5  * Driver for Microchip 23k256 SPI RAM chips
11 #include <linux/mtd/mtd.h>
12 #include <linux/mtd/partitions.h>
30 	struct mtd_info		mtd;  member
39 #define to_mchp23k256_flash(x) container_of(x, struct mchp23k256_flash, mtd)
51 	for (i = flash->caps->addr_width; i > 0; i--, addr >>= 8)  in mchp23k256_addr2cmd()
57 	return 1 + flash->caps->addr_width;  in mchp23k256_cmdsz()
60 static int mchp23k256_write(struct mtd_info *mtd, loff_t to, size_t len,  in mchp23k256_write()  argument
63 	struct mchp23k256_flash *flash = to_mchp23k256_flash(mtd);  in mchp23k256_write()
84 	mutex_lock(&flash->lock);  in mchp23k256_write()
86 	ret = spi_sync(flash->spi, &message);  in mchp23k256_write()
88 	mutex_unlock(&flash->lock);  in mchp23k256_write()
94 		*retlen += message.actual_length - cmd_len;  in mchp23k256_write()
99 static int mchp23k256_read(struct mtd_info *mtd, loff_t from, size_t len,  in mchp23k256_read()  argument
102 	struct mchp23k256_flash *flash = to_mchp23k256_flash(mtd);  in mchp23k256_read()
124 	mutex_lock(&flash->lock);  in mchp23k256_read()
126 	ret = spi_sync(flash->spi, &message);  in mchp23k256_read()
128 	mutex_unlock(&flash->lock);  in mchp23k256_read()
134 		*retlen += message.actual_length - cmd_len;  in mchp23k256_read()
177 	flash = devm_kzalloc(&spi->dev, sizeof(*flash), GFP_KERNEL);  in mchp23k256_probe()
179 		return -ENOMEM;  in mchp23k256_probe()
181 	flash->spi = spi;  in mchp23k256_probe()
182 	mutex_init(&flash->lock);  in mchp23k256_probe()
189 	data = dev_get_platdata(&spi->dev);  in mchp23k256_probe()
191 	flash->caps = of_device_get_match_data(&spi->dev);  in mchp23k256_probe()
192 	if (!flash->caps)  in mchp23k256_probe()
193 		flash->caps = &mchp23k256_caps;  in mchp23k256_probe()
195 	mtd_set_of_node(&flash->mtd, spi->dev.of_node);  in mchp23k256_probe()
196 	flash->mtd.dev.parent	= &spi->dev;  in mchp23k256_probe()
197 	flash->mtd.type		= MTD_RAM;  in mchp23k256_probe()
198 	flash->mtd.flags	= MTD_CAP_RAM;  in mchp23k256_probe()
199 	flash->mtd.writesize	= 1;  in mchp23k256_probe()
200 	flash->mtd.size		= flash->caps->size;  in mchp23k256_probe()
201 	flash->mtd._read	= mchp23k256_read;  in mchp23k256_probe()
202 	flash->mtd._write	= mchp23k256_write;  in mchp23k256_probe()
204 	err = mtd_device_register(&flash->mtd, data ? data->parts : NULL,  in mchp23k256_probe()
205 				  data ? data->nr_parts : 0);  in mchp23k256_probe()
216 	WARN_ON(mtd_device_unregister(&flash->mtd));  in mchp23k256_remove()
257 MODULE_DESCRIPTION("MTD SPI driver for MCHP23K256 RAM chips");