Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S935027AbdDSQBF (ORCPT ); Wed, 19 Apr 2017 12:01:05 -0400 Received: from mail-it0-f66.google.com ([209.85.214.66]:33654 "EHLO mail-it0-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1765686AbdDSQBC (ORCPT ); Wed, 19 Apr 2017 12:01:02 -0400 MIME-Version: 1.0 In-Reply-To: References: <20170419152305.17226-1-andrew.smirnov@gmail.com> <20170419152305.17226-5-andrew.smirnov@gmail.com> From: Andrey Smirnov Date: Wed, 19 Apr 2017 09:01:00 -0700 Message-ID: Subject: Re: [PATCH v3 5/6] mtd: dataflash: Make use of "extened device information" To: Marek Vasut Cc: linux-mtd@lists.infradead.org, Chris Healy , David Woodhouse , Brian Norris , Boris Brezillon , Richard Weinberger , Cyrille Pitchen , linux-kernel Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 7955 Lines: 205 On Wed, Apr 19, 2017 at 8:42 AM, Marek Vasut wrote: > On 04/19/2017 05:23 PM, Andrey Smirnov wrote: >> In anticipation of supporting chips that need it, extend the size of >> struct flash_info's 'jedec_id' field to make room 2 byte of extended >> device information as well as add code to fetch this data during >> jedec_probe(). >> >> Cc: cphealy@gmail.com >> Cc: David Woodhouse >> Cc: Brian Norris >> Cc: Boris Brezillon >> Cc: Marek Vasut >> Cc: Richard Weinberger >> Cc: Cyrille Pitchen >> Cc: linux-kernel@vger.kernel.org >> Signed-off-by: Andrey Smirnov >> --- >> >> Changes since [v2]: >> >> - Make 'id' have same size as 'jedec' >> >> - Get rid of eid_mask variable in favour of using GENMASK >> in-place >> >> Changes since [v1]: >> >> - Formatting >> >> [v1] http://lkml.kernel.org/r/20170411161722.11164-1-andrew.smirnov@gmail.com >> [v2] http://lkml.kernel.org/r/20170418142127.23301-3-andrew.smirnov@gmail.com >> >> drivers/mtd/devices/mtd_dataflash.c | 115 +++++++++++++++++++++--------------- >> 1 file changed, 68 insertions(+), 47 deletions(-) >> >> diff --git a/drivers/mtd/devices/mtd_dataflash.c b/drivers/mtd/devices/mtd_dataflash.c >> index 2d3e403..941e8b7 100644 >> --- a/drivers/mtd/devices/mtd_dataflash.c >> +++ b/drivers/mtd/devices/mtd_dataflash.c >> @@ -687,7 +687,7 @@ struct flash_info { >> /* JEDEC id has a high byte of zero plus three data bytes: >> * the manufacturer id, then a two byte device id. >> */ >> - u32 jedec_id; >> + u64 jedec_id; >> >> /* The size listed here is what works with OP_ERASE_PAGE. */ >> unsigned nr_pages; >> @@ -710,62 +710,34 @@ static struct flash_info dataflash_data[] = { >> * These newer chips also support 128-byte security registers (with >> * 64 bytes one-time-programmable) and software write-protection. >> */ >> - { "AT45DB011B", 0x1f2200, 512, 264, 9, SUP_POW2PS}, >> - { "at45db011d", 0x1f2200, 512, 256, 8, SUP_POW2PS | IS_POW2PS}, >> + { "AT45DB011B", 0x1f22000000, 512, 264, 9, SUP_POW2PS}, >> + { "at45db011d", 0x1f22000000, 512, 256, 8, SUP_POW2PS | IS_POW2PS}, >> >> - { "AT45DB021B", 0x1f2300, 1024, 264, 9, SUP_POW2PS}, >> - { "at45db021d", 0x1f2300, 1024, 256, 8, SUP_POW2PS | IS_POW2PS}, >> + { "AT45DB021B", 0x1f23000000, 1024, 264, 9, SUP_POW2PS}, >> + { "at45db021d", 0x1f23000000, 1024, 256, 8, SUP_POW2PS | IS_POW2PS}, >> >> - { "AT45DB041x", 0x1f2400, 2048, 264, 9, SUP_POW2PS}, >> - { "at45db041d", 0x1f2400, 2048, 256, 8, SUP_POW2PS | IS_POW2PS}, >> + { "AT45DB041x", 0x1f24000000, 2048, 264, 9, SUP_POW2PS}, >> + { "at45db041d", 0x1f24000000, 2048, 256, 8, SUP_POW2PS | IS_POW2PS}, >> >> - { "AT45DB081B", 0x1f2500, 4096, 264, 9, SUP_POW2PS}, >> - { "at45db081d", 0x1f2500, 4096, 256, 8, SUP_POW2PS | IS_POW2PS}, >> + { "AT45DB081B", 0x1f25000000, 4096, 264, 9, SUP_POW2PS}, >> + { "at45db081d", 0x1f25000000, 4096, 256, 8, SUP_POW2PS | IS_POW2PS}, >> >> - { "AT45DB161x", 0x1f2600, 4096, 528, 10, SUP_POW2PS}, >> - { "at45db161d", 0x1f2600, 4096, 512, 9, SUP_POW2PS | IS_POW2PS}, >> + { "AT45DB161x", 0x1f26000000, 4096, 528, 10, SUP_POW2PS}, >> + { "at45db161d", 0x1f26000000, 4096, 512, 9, SUP_POW2PS | IS_POW2PS}, >> >> - { "AT45DB321x", 0x1f2700, 8192, 528, 10, 0}, /* rev C */ >> + { "AT45DB321x", 0x1f27000000, 8192, 528, 10, 0}, /* rev C */ >> >> - { "AT45DB321x", 0x1f2701, 8192, 528, 10, SUP_POW2PS}, >> - { "at45db321d", 0x1f2701, 8192, 512, 9, SUP_POW2PS | IS_POW2PS}, >> + { "AT45DB321x", 0x1f27010000, 8192, 528, 10, SUP_POW2PS}, >> + { "at45db321d", 0x1f27010000, 8192, 512, 9, SUP_POW2PS | IS_POW2PS}, >> >> - { "AT45DB642x", 0x1f2800, 8192, 1056, 11, SUP_POW2PS}, >> - { "at45db642d", 0x1f2800, 8192, 1024, 10, SUP_POW2PS | IS_POW2PS}, >> + { "AT45DB642x", 0x1f28000000, 8192, 1056, 11, SUP_POW2PS}, >> + { "at45db642d", 0x1f28000000, 8192, 1024, 10, SUP_POW2PS | IS_POW2PS}, >> }; >> >> -static struct flash_info *jedec_probe(struct spi_device *spi) >> +static struct flash_info *jedec_lookup(struct spi_device *spi, u64 jedec) >> { >> - int ret; >> - u8 code = OP_READ_ID; >> - u8 id[3]; >> - u32 jedec; >> - struct flash_info *info; >> int status; >> - >> - /* >> - * JEDEC also defines an optional "extended device information" >> - * string for after vendor-specific data, after the three bytes >> - * we use here. Supporting some chips might require using it. >> - * >> - * If the vendor ID isn't Atmel's (0x1f), assume this call failed. >> - * That's not an error; only rev C and newer chips handle it, and >> - * only Atmel sells these chips. >> - */ >> - ret = spi_write_then_read(spi, &code, 1, id, 3); >> - if (ret < 0) { >> - dev_dbg(&spi->dev, "error %d reading JEDEC ID\n", ret); >> - return ERR_PTR(ret); >> - } >> - >> - if (id[0] != CFI_MFR_ATMEL) >> - return NULL; >> - >> - jedec = id[0]; >> - jedec = jedec << 8; >> - jedec |= id[1]; >> - jedec = jedec << 8; >> - jedec |= id[2]; >> + struct flash_info *info; >> >> for (info = dataflash_data; >> info < dataflash_data + ARRAY_SIZE(dataflash_data); >> @@ -793,12 +765,61 @@ static struct flash_info *jedec_probe(struct spi_device *spi) >> } >> } >> >> + return NULL; >> +} >> + >> +static struct flash_info *jedec_probe(struct spi_device *spi) >> +{ >> + int ret; >> + u8 code = OP_READ_ID; >> + u64 jedec; >> + u8 id[sizeof(jedec)] = {0}; >> + const unsigned int id_size = 5; >> + const unsigned int first_byte = sizeof(id) - id_size; >> + struct flash_info *info; >> + >> + /* >> + * JEDEC also defines an optional "extended device information" >> + * string for after vendor-specific data, after the three bytes >> + * we use here. Supporting some chips might require using it. >> + * >> + * If the vendor ID isn't Atmel's (0x1f), assume this call failed. >> + * That's not an error; only rev C and newer chips handle it, and >> + * only Atmel sells these chips. >> + */ >> + ret = spi_write_then_read(spi, &code, 1, &id[first_byte], id_size); > > Hm, looking at this again, what prevents you from reading these bytes > into &id[0] ? Might be easier, ie. > > ret = spi_write_then_read(spi, &code, 1, id, id_size); > Then I'd have to add 6 more '0's to each of the IDs in dataflash_data, which would make that code even less readable. >> + if (ret < 0) { >> + pr_debug("%s: error %d reading JEDEC ID\n", >> + dev_name(&spi->dev), ret); >> + return ERR_PTR(ret); >> + } >> + >> + if (id[first_byte] != CFI_MFR_ATMEL) > > if (id[0] != CFI_MFR_ATMEL) > >> + return NULL; >> + >> + jedec = be64_to_cpup((__be64 *)id); >> + >> + info = jedec_lookup(spi, jedec); > > ... define these somewhere at the beginning of the dataflash code ... > #define DATAFLASH_MASK_STD GENMASK(63, 40) > #define DATAFLASH_MASK_EXT GENMASK(63, 16) > > ... then ... > info = jedec_lookup(spi, jedec & DATAFLASH_MASK_EXT); > >> + if (info) >> + return info; >> + >> + /* >> + * Clear extended id bits (bits 0 through 15) and try to find >> + * a match again in case our chip does not support returning >> + * extended ID information and we got invalid bits instead >> + */ >> + jedec &= GENMASK_ULL(63, 16); > > info = jedec_lookup(spi, jedec & DATAFLASH_MASK_STD); > Sure, OK. Thanks, Andrey Smirnov