From 78f1ddf7bb6ee77815e8d91275356b453524140c Mon Sep 17 00:00:00 2001 From: Tudor Ambarus Date: Sat, 2 Nov 2019 11:23:37 +0000 Subject: mtd: spi-nor: Describe all the Reg Ops Document all the Register Operations. Signed-off-by: Tudor Ambarus Reviewed-by: Vignesh Raghavendra --- drivers/mtd/spi-nor/spi-nor.c | 138 ++++++++++++++++++++++++++++++++++++++---- 1 file changed, 127 insertions(+), 11 deletions(-) (limited to 'drivers/mtd') diff --git a/drivers/mtd/spi-nor/spi-nor.c b/drivers/mtd/spi-nor/spi-nor.c index a96704fcb845..83da51047848 100644 --- a/drivers/mtd/spi-nor/spi-nor.c +++ b/drivers/mtd/spi-nor/spi-nor.c @@ -388,9 +388,11 @@ static ssize_t spi_nor_write_data(struct spi_nor *nor, loff_t to, size_t len, return nor->controller_ops->write(nor, to, len, buf); } -/* - * Set write enable latch with Write Enable command. - * Returns negative if error occurred. +/** + * spi_nor_write_enable() - Set write enable latch with Write Enable command. + * @nor: pointer to 'struct spi_nor'. + * + * Return: 0 on success, -errno otherwise. */ static int spi_nor_write_enable(struct spi_nor *nor) { @@ -415,8 +417,11 @@ static int spi_nor_write_enable(struct spi_nor *nor) return ret; } -/* - * Send write disable instruction to the chip. +/** + * spi_nor_write_disable() - Send Write Disable instruction to the chip. + * @nor: pointer to 'struct spi_nor'. + * + * Return: 0 on success, -errno otherwise. */ static int spi_nor_write_disable(struct spi_nor *nor) { @@ -534,6 +539,14 @@ static int spi_nor_read_cr(struct spi_nor *nor, u8 *cr) return ret; } +/** + * macronix_set_4byte() - Set 4-byte address mode for Macronix flashes. + * @nor: pointer to 'struct spi_nor'. + * @enable: true to enter the 4-byte address mode, false to exit the 4-byte + * address mode. + * + * Return: 0 on success, -errno otherwise. + */ static int macronix_set_4byte(struct spi_nor *nor, bool enable) { int ret; @@ -562,6 +575,14 @@ static int macronix_set_4byte(struct spi_nor *nor, bool enable) return ret; } +/** + * st_micron_set_4byte() - Set 4-byte address mode for ST and Micron flashes. + * @nor: pointer to 'struct spi_nor'. + * @enable: true to enter the 4-byte address mode, false to exit the 4-byte + * address mode. + * + * Return: 0 on success, -errno otherwise. + */ static int st_micron_set_4byte(struct spi_nor *nor, bool enable) { int ret; @@ -577,6 +598,14 @@ static int st_micron_set_4byte(struct spi_nor *nor, bool enable) return spi_nor_write_disable(nor); } +/** + * spansion_set_4byte() - Set 4-byte address mode for Spansion flashes. + * @nor: pointer to 'struct spi_nor'. + * @enable: true to enter the 4-byte address mode, false to exit the 4-byte + * address mode. + * + * Return: 0 on success, -errno otherwise. + */ static int spansion_set_4byte(struct spi_nor *nor, bool enable) { int ret; @@ -602,6 +631,13 @@ static int spansion_set_4byte(struct spi_nor *nor, bool enable) return ret; } +/** + * spi_nor_write_ear() - Write Extended Address Register. + * @nor: pointer to 'struct spi_nor'. + * @ear: value to write to the Extended Address Register. + * + * Return: 0 on success, -errno otherwise. + */ static int spi_nor_write_ear(struct spi_nor *nor, u8 ear) { int ret; @@ -627,6 +663,14 @@ static int spi_nor_write_ear(struct spi_nor *nor, u8 ear) return ret; } +/** + * winbond_set_4byte() - Set 4-byte address mode for Winbond flashes. + * @nor: pointer to 'struct spi_nor'. + * @enable: true to enter the 4-byte address mode, false to exit the 4-byte + * address mode. + * + * Return: 0 on success, -errno otherwise. + */ static int winbond_set_4byte(struct spi_nor *nor, bool enable) { int ret; @@ -651,6 +695,14 @@ static int winbond_set_4byte(struct spi_nor *nor, bool enable) return spi_nor_write_disable(nor); } +/** + * spi_nor_xread_sr() - Read the Status Register on S3AN flashes. + * @nor: pointer to 'struct spi_nor'. + * @sr: pointer to a DMA-able buffer where the value of the + * Status Register will be written. + * + * Return: 0 on success, -errno otherwise. + */ static int spi_nor_xread_sr(struct spi_nor *nor, u8 *sr) { int ret; @@ -674,6 +726,13 @@ static int spi_nor_xread_sr(struct spi_nor *nor, u8 *sr) return ret; } +/** + * s3an_sr_ready() - Query the Status Register of the S3AN flash to see if the + * flash is ready for new commands. + * @nor: pointer to 'struct spi_nor'. + * + * Return: 0 on success, -errno otherwise. + */ static int s3an_sr_ready(struct spi_nor *nor) { int ret; @@ -685,6 +744,10 @@ static int s3an_sr_ready(struct spi_nor *nor) return !!(nor->bouncebuf[0] & XSR_RDY); } +/** + * spi_nor_clear_sr() - Clear the Status Register. + * @nor: pointer to 'struct spi_nor'. + */ static void spi_nor_clear_sr(struct spi_nor *nor) { int ret; @@ -706,6 +769,13 @@ static void spi_nor_clear_sr(struct spi_nor *nor) dev_dbg(nor->dev, "error %d clearing SR\n", ret); } +/** + * spi_nor_sr_ready() - Query the Status Register to see if the flash is ready + * for new commands. + * @nor: pointer to 'struct spi_nor'. + * + * Return: 0 on success, -errno otherwise. + */ static int spi_nor_sr_ready(struct spi_nor *nor) { int ret = spi_nor_read_sr(nor, nor->bouncebuf); @@ -727,6 +797,10 @@ static int spi_nor_sr_ready(struct spi_nor *nor) return !(nor->bouncebuf[0] & SR_WIP); } +/** + * spi_nor_clear_fsr() - Clear the Flag Status Register. + * @nor: pointer to 'struct spi_nor'. + */ static void spi_nor_clear_fsr(struct spi_nor *nor) { int ret; @@ -748,6 +822,13 @@ static void spi_nor_clear_fsr(struct spi_nor *nor) dev_dbg(nor->dev, "error %d clearing FSR\n", ret); } +/** + * spi_nor_fsr_ready() - Query the Flag Status Register to see if the flash is + * ready for new commands. + * @nor: pointer to 'struct spi_nor'. + * + * Return: 0 on success, -errno otherwise. + */ static int spi_nor_fsr_ready(struct spi_nor *nor) { int ret = spi_nor_read_fsr(nor, nor->bouncebuf); @@ -772,6 +853,12 @@ static int spi_nor_fsr_ready(struct spi_nor *nor) return nor->bouncebuf[0] & FSR_READY; } +/** + * spi_nor_ready() - Query the flash to see if it is ready for new commands. + * @nor: pointer to 'struct spi_nor'. + * + * Return: 0 on success, -errno otherwise. + */ static int spi_nor_ready(struct spi_nor *nor) { int sr, fsr; @@ -788,9 +875,13 @@ static int spi_nor_ready(struct spi_nor *nor) return sr && fsr; } -/* - * Service routine to read status register until ready, or timeout occurs. - * Returns non-zero if error. +/** + * spi_nor_wait_till_ready_with_timeout() - Service routine to read the + * Status Register until ready, or timeout occurs. + * @nor: pointer to "struct spi_nor". + * @timeout_jiffies: jiffies to wait until timeout. + * + * Return: 0 on success, -errno otherwise. */ static int spi_nor_wait_till_ready_with_timeout(struct spi_nor *nor, unsigned long timeout_jiffies) @@ -818,6 +909,13 @@ static int spi_nor_wait_till_ready_with_timeout(struct spi_nor *nor, return -ETIMEDOUT; } +/** + * spi_nor_wait_till_ready() - Wait for a predefined amount of time for the + * flash to be ready, or timeout occurs. + * @nor: pointer to "struct spi_nor". + * + * Return: 0 on success, -errno otherwise. + */ static int spi_nor_wait_till_ready(struct spi_nor *nor) { return spi_nor_wait_till_ready_with_timeout(nor, @@ -880,6 +978,14 @@ static int spi_nor_write_sr_and_check(struct spi_nor *nor, u8 status_new, return ((nor->bouncebuf[0] & mask) != (status_new & mask)) ? -EIO : 0; } +/** + * spi_nor_write_sr2() - Write the Status Register 2 using the + * SPINOR_OP_WRSR2 (3eh) command. + * @nor: pointer to 'struct spi_nor'. + * @sr2: pointer to DMA-able buffer to write to the Status Register 2. + * + * Return: 0 on success, -errno otherwise. + */ static int spi_nor_write_sr2(struct spi_nor *nor, const u8 *sr2) { int ret; @@ -909,6 +1015,15 @@ static int spi_nor_write_sr2(struct spi_nor *nor, const u8 *sr2) return spi_nor_wait_till_ready(nor); } +/** + * spi_nor_read_sr2() - Read the Status Register 2 using the + * SPINOR_OP_RDSR2 (3fh) command. + * @nor: pointer to 'struct spi_nor'. + * @sr2: pointer to DMA-able buffer where the value of the + * Status Register 2 will be written. + * + * Return: 0 on success, -errno otherwise. + */ static int spi_nor_read_sr2(struct spi_nor *nor, u8 *sr2) { int ret; @@ -932,10 +1047,11 @@ static int spi_nor_read_sr2(struct spi_nor *nor, u8 *sr2) return ret; } -/* - * Erase the whole flash memory +/** + * spi_nor_erase_chip() - Erase the entire flash memory. + * @nor: pointer to 'struct spi_nor'. * - * Returns 0 if successful, non-zero otherwise. + * Return: 0 on success, -errno otherwise. */ static int spi_nor_erase_chip(struct spi_nor *nor) { -- cgit