1 // SPDX-License-Identifier: GPL-2.0
3  * SPI NOR Software Write Protection logic.
10 #include <linux/mtd/spi-nor.h>
18 	if (nor->flags & SNOR_F_HAS_SR_BP3_BIT6)  in spi_nor_get_sr_bp_mask()
21 	if (nor->flags & SNOR_F_HAS_4BIT_BP)  in spi_nor_get_sr_bp_mask()
29 	if (nor->flags & SNOR_F_HAS_SR_TB_BIT6)  in spi_nor_get_sr_tb_mask()
42 	unsigned int sector_size = nor->info->sector_size ?: SPI_NOR_DEFAULT_SECTOR_SIZE;  in spi_nor_get_min_prot_length_sr()
43 	u64 n_sectors = div_u64(nor->params->size, sector_size);  in spi_nor_get_min_prot_length_sr()
46 	/* Reserved one for "protect none" and one for "protect all". */  in spi_nor_get_min_prot_length_sr()
47 	bp_slots = (1 << hweight8(mask)) - 2;  in spi_nor_get_min_prot_length_sr()
51 		return sector_size << (bp_slots_needed - bp_slots);  in spi_nor_get_min_prot_length_sr()
59 	struct mtd_info *mtd = &nor->mtd;  in spi_nor_get_locked_range_sr()
65 	if (nor->flags & SNOR_F_HAS_SR_BP3_BIT6 && val & SR_BP3_BIT6)  in spi_nor_get_locked_range_sr()
78 	*len = min_prot_len << (bp - 1);  in spi_nor_get_locked_range_sr()
80 	if (*len > mtd->size)  in spi_nor_get_locked_range_sr()
81 		*len = mtd->size;  in spi_nor_get_locked_range_sr()
83 	if (nor->flags & SNOR_F_HAS_SR_TB && sr & tb_mask)  in spi_nor_get_locked_range_sr()
86 		*ofs = mtd->size - *len;  in spi_nor_get_locked_range_sr()
108 		/* Requested range is a sub-range of locked range */  in spi_nor_check_lock_status_sr()
131  *   - SEC: sector/block protect - only handle SEC=0 (block protect)
132  *   - CMP: complement protect - only support CMP=0 (range is not complemented)
135  *   - TB: top/bottom protect
140  *  --------------------------------------------------------------------------
149  *  ------|-------|-------|-------|-------|---------------|-------------------
161 	struct mtd_info *mtd = &nor->mtd;  in spi_nor_sr_lock()
168 	bool can_be_top = true, can_be_bottom = nor->flags & SNOR_F_HAS_SR_TB;  in spi_nor_sr_lock()
171 	ret = spi_nor_read_sr(nor, nor->bouncebuf);  in spi_nor_sr_lock()
175 	status_old = nor->bouncebuf[0];  in spi_nor_sr_lock()
186 	if (!spi_nor_is_locked_sr(nor, ofs + len, mtd->size - (ofs + len),  in spi_nor_sr_lock()
191 		return -EINVAL;  in spi_nor_sr_lock()
198 		lock_len = mtd->size - ofs;  in spi_nor_sr_lock()
202 	if (lock_len == mtd->size) {  in spi_nor_sr_lock()
206 		pow = ilog2(lock_len) - ilog2(min_prot_len) + 1;  in spi_nor_sr_lock()
209 		if (nor->flags & SNOR_F_HAS_SR_BP3_BIT6 && val & SR_BP3)  in spi_nor_sr_lock()
213 			return -EINVAL;  in spi_nor_sr_lock()
217 			return -EINVAL;  in spi_nor_sr_lock()
224 	 * wrongly tied to GND (that includes internal pull-downs).  in spi_nor_sr_lock()
227 	if (!(nor->flags & SNOR_F_NO_WP))  in spi_nor_sr_lock()
239 		return -EINVAL;  in spi_nor_sr_lock()
251 	struct mtd_info *mtd = &nor->mtd;  in spi_nor_sr_unlock()
258 	bool can_be_top = true, can_be_bottom = nor->flags & SNOR_F_HAS_SR_TB;  in spi_nor_sr_unlock()
261 	ret = spi_nor_read_sr(nor, nor->bouncebuf);  in spi_nor_sr_unlock()
265 	status_old = nor->bouncebuf[0];  in spi_nor_sr_unlock()
276 	if (!spi_nor_is_unlocked_sr(nor, ofs + len, mtd->size - (ofs + len),  in spi_nor_sr_unlock()
281 		return -EINVAL;  in spi_nor_sr_unlock()
288 		lock_len = mtd->size - (ofs + len);  in spi_nor_sr_unlock()
296 		pow = ilog2(lock_len) - ilog2(min_prot_len) + 1;  in spi_nor_sr_unlock()
299 		if (nor->flags & SNOR_F_HAS_SR_BP3_BIT6 && val & SR_BP3)  in spi_nor_sr_unlock()
302 		/* Some power-of-two sizes are not supported */  in spi_nor_sr_unlock()
304 			return -EINVAL;  in spi_nor_sr_unlock()
309 	/* Don't protect status register if we're fully unlocked */  in spi_nor_sr_unlock()
322 		return -EINVAL;  in spi_nor_sr_unlock()
338 	ret = spi_nor_read_sr(nor, nor->bouncebuf);  in spi_nor_sr_is_locked()
342 	return spi_nor_is_locked_sr(nor, ofs, len, nor->bouncebuf[0]);  in spi_nor_sr_is_locked()
353 	nor->params->locking_ops = &spi_nor_sr_locking_ops;  in spi_nor_init_default_locking_ops()
365 	ret = nor->params->locking_ops->lock(nor, ofs, len);  in spi_nor_lock()
380 	ret = nor->params->locking_ops->unlock(nor, ofs, len);  in spi_nor_unlock()
395 	ret = nor->params->locking_ops->is_locked(nor, ofs, len);  in spi_nor_is_locked()
402  * spi_nor_try_unlock_all() - Tries to unlock the entire flash memory array.
405  * Some SPI NOR flashes are write protected by default after a power-on reset
406  * cycle, in order to avoid inadvertent writes during power-up. Backward
407  * compatibility imposes to unlock the entire flash memory array at power-up
411  * write-protected. Thus any errors are ignored.
417 	if (!(nor->flags & SNOR_F_HAS_LOCK))  in spi_nor_try_unlock_all()
420 	dev_dbg(nor->dev, "Unprotecting entire flash array\n");  in spi_nor_try_unlock_all()
422 	ret = spi_nor_unlock(&nor->mtd, 0, nor->params->size);  in spi_nor_try_unlock_all()
424 		dev_dbg(nor->dev, "Failed to unlock the entire flash memory array\n");  in spi_nor_try_unlock_all()
429 	struct mtd_info *mtd = &nor->mtd;  in spi_nor_set_mtd_locking_ops()
431 	if (!nor->params->locking_ops)  in spi_nor_set_mtd_locking_ops()
434 	mtd->_lock = spi_nor_lock;  in spi_nor_set_mtd_locking_ops()
435 	mtd->_unlock = spi_nor_unlock;  in spi_nor_set_mtd_locking_ops()
436 	mtd->_is_locked = spi_nor_is_locked;  in spi_nor_set_mtd_locking_ops()