1 // SPDX-License-Identifier: GPL-2.0
3  * SPI NOR Software Write Protection logic.
9 #include <linux/mtd/spi-nor.h>
17 	if (nor->flags & SNOR_F_HAS_SR_BP3_BIT6)  in spi_nor_get_sr_bp_mask()
20 	if (nor->flags & SNOR_F_HAS_4BIT_BP)  in spi_nor_get_sr_bp_mask()
28 	if (nor->flags & SNOR_F_HAS_SR_TB_BIT6)  in spi_nor_get_sr_tb_mask()
39 	/* Reserved one for "protect none" and one for "protect all". */  in spi_nor_get_min_prot_length_sr()
40 	bp_slots = (1 << hweight8(mask)) - 2;  in spi_nor_get_min_prot_length_sr()
41 	bp_slots_needed = ilog2(nor->info->n_sectors);  in spi_nor_get_min_prot_length_sr()
44 		return nor->info->sector_size <<  in spi_nor_get_min_prot_length_sr()
45 			(bp_slots_needed - bp_slots);  in spi_nor_get_min_prot_length_sr()
47 		return nor->info->sector_size;  in spi_nor_get_min_prot_length_sr()
53 	struct mtd_info *mtd = &nor->mtd;  in spi_nor_get_locked_range_sr()
59 	if (nor->flags & SNOR_F_HAS_SR_BP3_BIT6 && val & SR_BP3_BIT6)  in spi_nor_get_locked_range_sr()
72 	*len = min_prot_len << (bp - 1);  in spi_nor_get_locked_range_sr()
74 	if (*len > mtd->size)  in spi_nor_get_locked_range_sr()
75 		*len = mtd->size;  in spi_nor_get_locked_range_sr()
77 	if (nor->flags & SNOR_F_HAS_SR_TB && sr & tb_mask)  in spi_nor_get_locked_range_sr()
80 		*ofs = mtd->size - *len;  in spi_nor_get_locked_range_sr()
102 		/* Requested range is a sub-range of locked range */  in spi_nor_check_lock_status_sr()
126  *   - SEC: sector/block protect - only handle SEC=0 (block protect)
127  *   - CMP: complement protect - only support CMP=0 (range is not complemented)
130  *   - TB: top/bottom protect
135  *  --------------------------------------------------------------------------
144  *  ------|-------|-------|-------|-------|---------------|-------------------
156 	struct mtd_info *mtd = &nor->mtd;  in spi_nor_sr_lock()
163 	bool can_be_top = true, can_be_bottom = nor->flags & SNOR_F_HAS_SR_TB;  in spi_nor_sr_lock()
166 	ret = spi_nor_read_sr(nor, nor->bouncebuf);  in spi_nor_sr_lock()
170 	status_old = nor->bouncebuf[0];  in spi_nor_sr_lock()
181 	if (!spi_nor_is_locked_sr(nor, ofs + len, mtd->size - (ofs + len),  in spi_nor_sr_lock()
186 		return -EINVAL;  in spi_nor_sr_lock()
193 		lock_len = mtd->size - ofs;  in spi_nor_sr_lock()
197 	if (lock_len == mtd->size) {  in spi_nor_sr_lock()
201 		pow = ilog2(lock_len) - ilog2(min_prot_len) + 1;  in spi_nor_sr_lock()
204 		if (nor->flags & SNOR_F_HAS_SR_BP3_BIT6 && val & SR_BP3)  in spi_nor_sr_lock()
208 			return -EINVAL;  in spi_nor_sr_lock()
212 			return -EINVAL;  in spi_nor_sr_lock()
229 		return -EINVAL;  in spi_nor_sr_lock()
241 	struct mtd_info *mtd = &nor->mtd;  in spi_nor_sr_unlock()
248 	bool can_be_top = true, can_be_bottom = nor->flags & SNOR_F_HAS_SR_TB;  in spi_nor_sr_unlock()
251 	ret = spi_nor_read_sr(nor, nor->bouncebuf);  in spi_nor_sr_unlock()
255 	status_old = nor->bouncebuf[0];  in spi_nor_sr_unlock()
266 	if (!spi_nor_is_unlocked_sr(nor, ofs + len, mtd->size - (ofs + len),  in spi_nor_sr_unlock()
271 		return -EINVAL;  in spi_nor_sr_unlock()
278 		lock_len = mtd->size - (ofs + len);  in spi_nor_sr_unlock()
286 		pow = ilog2(lock_len) - ilog2(min_prot_len) + 1;  in spi_nor_sr_unlock()
289 		if (nor->flags & SNOR_F_HAS_SR_BP3_BIT6 && val & SR_BP3)  in spi_nor_sr_unlock()
292 		/* Some power-of-two sizes are not supported */  in spi_nor_sr_unlock()
294 			return -EINVAL;  in spi_nor_sr_unlock()
299 	/* Don't protect status register if we're fully unlocked */  in spi_nor_sr_unlock()
312 		return -EINVAL;  in spi_nor_sr_unlock()
328 	ret = spi_nor_read_sr(nor, nor->bouncebuf);  in spi_nor_sr_is_locked()
332 	return spi_nor_is_locked_sr(nor, ofs, len, nor->bouncebuf[0]);  in spi_nor_sr_is_locked()
343 	nor->params->locking_ops = &spi_nor_sr_locking_ops;  in spi_nor_init_default_locking_ops()
355 	ret = nor->params->locking_ops->lock(nor, ofs, len);  in spi_nor_lock()
370 	ret = nor->params->locking_ops->unlock(nor, ofs, len);  in spi_nor_unlock()
385 	ret = nor->params->locking_ops->is_locked(nor, ofs, len);  in spi_nor_is_locked()
392  * spi_nor_try_unlock_all() - Tries to unlock the entire flash memory array.
395  * Some SPI NOR flashes are write protected by default after a power-on reset
396  * cycle, in order to avoid inadvertent writes during power-up. Backward
397  * compatibility imposes to unlock the entire flash memory array at power-up
401  * write-protected. Thus any errors are ignored.
407 	if (!(nor->flags & SNOR_F_HAS_LOCK))  in spi_nor_try_unlock_all()
410 	dev_dbg(nor->dev, "Unprotecting entire flash array\n");  in spi_nor_try_unlock_all()
412 	ret = spi_nor_unlock(&nor->mtd, 0, nor->params->size);  in spi_nor_try_unlock_all()
414 		dev_dbg(nor->dev, "Failed to unlock the entire flash memory array\n");  in spi_nor_try_unlock_all()
419 	struct mtd_info *mtd = &nor->mtd;  in spi_nor_set_mtd_locking_ops()
421 	if (!nor->params->locking_ops)  in spi_nor_set_mtd_locking_ops()
424 	mtd->_lock = spi_nor_lock;  in spi_nor_set_mtd_locking_ops()
425 	mtd->_unlock = spi_nor_unlock;  in spi_nor_set_mtd_locking_ops()
426 	mtd->_is_locked = spi_nor_is_locked;  in spi_nor_set_mtd_locking_ops()