From 1103b8517041b08286cae0da8481bef9164c961a Mon Sep 17 00:00:00 2001 From: Brian Norris Date: Fri, 27 Mar 2015 10:29:50 -0700 Subject: [PATCH] mtd: m25p80: bind to "nor-jedec" ID, for auto-detection MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Use the new 'nor-jedec' binding to provide automatic detection of flash that use the 0x9F READ ID opcode. This can help for use cases where platforms just specify compatibility with "m25p80", and then see messages like this: m25p80 spi32766.0: found s25fl256s1, expected m25p80 Instead, they can just specify the generic string and see this: m25p80 spi32766.0: s25fl256s1 (32768 Kbytes) Also, update the language about m25p_ids[] to straighten out the expectations here. We should no longer need to continuously grow the m25p_ids[] table, and in fact, we might want to start removing entries which are not used in device trees so far, so we can just default to auto-detection as much as possible in the future. Signed-off-by: Brian Norris Cc: Rafał Miłecki --- drivers/mtd/devices/m25p80.c | 21 ++++++++++++++++++--- 1 file changed, 18 insertions(+), 3 deletions(-) diff --git a/drivers/mtd/devices/m25p80.c b/drivers/mtd/devices/m25p80.c index 85e35467fba6..7c8b1694a134 100644 --- a/drivers/mtd/devices/m25p80.c +++ b/drivers/mtd/devices/m25p80.c @@ -223,6 +223,8 @@ static int m25p_probe(struct spi_device *spi) */ if (data && data->type) flash_name = data->type; + else if (!strcmp(spi->modalias, "nor-jedec")) + flash_name = NULL; /* auto-detect */ else flash_name = spi->modalias; @@ -247,9 +249,16 @@ static int m25p_remove(struct spi_device *spi) } /* - * XXX This needs to be kept in sync with spi_nor_ids. We can't share - * it with spi-nor, because if this is built as a module then modpost - * won't be able to read it and add appropriate aliases. + * Do NOT add to this array without reading the following: + * + * Historically, many flash devices are bound to this driver by their name. But + * since most of these flash are compatible to some extent, and their + * differences can often be differentiated by the JEDEC read-ID command, we + * encourage new users to add support to the spi-nor library, and simply bind + * against a generic string here (e.g., "nor-jedec"). + * + * Many flash names are kept here in this list (as well as in spi-nor.c) to + * keep them available as module aliases for existing platforms. */ static const struct spi_device_id m25p_ids[] = { {"at25fs010"}, {"at25fs040"}, {"at25df041a"}, {"at25df321a"}, @@ -291,6 +300,12 @@ static const struct spi_device_id m25p_ids[] = { {"w25x64"}, {"w25q64"}, {"w25q80"}, {"w25q80bl"}, {"w25q128"}, {"w25q256"}, {"cat25c11"}, {"cat25c03"}, {"cat25c09"}, {"cat25c17"}, {"cat25128"}, + + /* + * Generic support for SPI NOR that can be identified by the JEDEC READ + * ID opcode (0x9F). Use this, if possible. + */ + {"nor-jedec"}, { }, }; MODULE_DEVICE_TABLE(spi, m25p_ids); -- 2.20.1