From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752874AbbCPIq1 (ORCPT ); Mon, 16 Mar 2015 04:46:27 -0400 Received: from mail-wi0-f169.google.com ([209.85.212.169]:33377 "EHLO mail-wi0-f169.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750749AbbCPIqY (ORCPT ); Mon, 16 Mar 2015 04:46:24 -0400 MIME-Version: 1.0 In-Reply-To: <20150313073829.GH12966@brian-ubuntu> References: <20150313073829.GH12966@brian-ubuntu> Date: Mon, 16 Mar 2015 16:46:21 +0800 Message-ID: Subject: Re: [PATCH v2] mtd:spi-nor: Add Altera EPCQ Driver From: Viet Nga Dao To: Brian Norris Cc: Viet Nga Dao , David Woodhouse , "linux-mtd@lists.infradead.org" , "linux-kernel@vger.kernel.org" , "devicetree@vger.kernel.org" Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Mar 13, 2015 at 3:38 PM, Brian Norris wrote: > Hi Viet, > > On Wed, Feb 11, 2015 at 12:53:00PM +0800, Viet Nga Dao wrote: >> From: Viet Nga Dao >> >> Altera EPCQ Controller is a soft IP which enables access to Altera EPCQ and >> EPCS flash chips. This patch adds driver for these devices. >> >> Signed-off-by: VIET NGA DAO >> >> --- >> v2: >> - Change to spi_nor structure >> - Add lock and unlock functions for spi_nor >> - Simplify the altera_epcq_lock function >> - Replace reg by compatible in device tree >> --- >> .../devicetree/bindings/mtd/altera_epcq.txt | 45 ++ >> drivers/mtd/spi-nor/Kconfig | 12 + >> drivers/mtd/spi-nor/Makefile | 1 + >> drivers/mtd/spi-nor/altera_epcq.c | 507 ++++++++++++++++++++ >> drivers/mtd/spi-nor/altera_epcq.h | 116 +++++ >> drivers/mtd/spi-nor/spi-nor.c | 86 ++++- >> include/linux/mtd/spi-nor.h | 3 +- >> 7 files changed, 764 insertions(+), 6 deletions(-) >> create mode 100644 Documentation/devicetree/bindings/mtd/altera_epcq.txt >> create mode 100644 drivers/mtd/spi-nor/altera_epcq.c >> create mode 100644 drivers/mtd/spi-nor/altera_epcq.h > > Please split this up into at least 2 patches, if not 3. One or more for > the spi-nor changes, split logically; one for your new driver; and maybe > a separate one for the binding documentation. > > Also, as Rafal noted, your patche is whitespace damaged, so I can't > apply or build it. > > Please make sure you can apply, build, and run your patch on top of > l2-mtd.git: > > http://git.infradead.org/l2-mtd.git > git://git.infradead.org/l2-mtd.git > > ... >> diff --git a/drivers/mtd/spi-nor/Kconfig b/drivers/mtd/spi-nor/Kconfig >> index 64a4f0e..83178b9 100644 >> --- a/drivers/mtd/spi-nor/Kconfig >> +++ b/drivers/mtd/spi-nor/Kconfig >> @@ -28,4 +28,16 @@ config SPI_FSL_QUADSPI >> This enables support for the Quad SPI controller in master mode. >> We only connect the NOR to this controller now. >> >> +config SPI_ALTERA_EPCQ >> + tristate "Support Altera EPCQ/EPCS Flash chips" >> + depends on OF >> + help >> + This enables access to Altera EPCQ/EPCS flash chips, used for data >> + storage. See the driver source for the current list, >> + or to add other chips. >> + >> + If you want to compile this driver as a module ( = code which can be >> + inserted in and removed from the running kernel whenever you want), >> + say M here and read . > > I don't think you need to explain what a module is here. Look at other > Kconfig entries as examples, but I think you can just drop that last > paragraph. > >> + >> endif # MTD_SPI_NOR > ... >> diff --git a/drivers/mtd/spi-nor/altera_epcq.c >> b/drivers/mtd/spi-nor/altera_epcq.c >> new file mode 100644 >> index 0000000..9db0d05 >> --- /dev/null >> +++ b/drivers/mtd/spi-nor/altera_epcq.c >> @@ -0,0 +1,507 @@ >> +/* >> + * Copyright (C) 2014 Altera Corporation. All rights reserved >> + * >> + * This program is free software; you can redistribute it and/or modify it >> + * under the terms and conditions of the GNU General Public License, >> + * version 2, as published by the Free Software Foundation. >> + * >> + * This program is distributed in the hope it will be useful, but WITHOUT >> + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or >> + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for >> + * more details. >> + * >> + * You should have received a copy of the GNU General Public License along with >> + * this program. If not, see . >> + */ >> + >> +#include >> +#include >> +#include >> +#include >> +#include >> +#include >> +#include >> +#include >> +#include >> +#include >> +#include >> +#include >> +#include >> +#include >> +#include >> +#include >> +#include >> +#include >> +#include >> +#include >> +#include >> + >> +#include "altera_epcq.h" >> + >> +static int altera_epcq_write_reg(struct spi_nor *nor, u8 opcode, u8 *val, >> + int len, int wr_en) >> +{ >> + return 0; >> +} >> + >> +static int altera_epcq_read_reg(struct spi_nor *nor, u8 opcode, u8 *val, >> + int len) >> +{ >> + struct altera_epcq_flash *flash = nor->priv; >> + struct altera_epcq *dev = flash->priv; >> + u32 data = 0; >> + u8 id[5]; >> + >> + switch (opcode) { >> + case SPINOR_OP_RDSR: >> + data = readl(dev->csr_base + EPCQ_SR_REG); >> + *val = (u8)data & EPCQ_SR_MASK; >> + break; >> + case SPINOR_OP_RDID: >> + /* opcode id */ >> + if (dev->is_epcs) { >> + data = readl(dev->csr_base + EPCQ_SID_REG); >> + id[4] = EPCS_OPCODE_ID; >> + } else { >> + data = readl(dev->csr_base + EPCQ_RDID_REG); >> + id[4] = EPCQ_OPCODE_ID; >> + } > > I think Rafal had some suggestions on changing how you match > IDs/devices. This, at least, doesn't look very good; you're faking a > particular ID, then matching it in spi-nor.c? > > You might be better off doing something like the *-nonjedec entries in > spi-nor.c, and just match a string, similar to what Rafal mentioned I > think. > >> + id[0] = 0xFF; /* non standard jedec id */ >> + id[1] = 0xFF; /* non standard jedec id */ >> + id[2] = 0xFF; /* non standard jedec id */ >> + id[3] = (u8)data & EPCQ_ID_MASK; /* device id */ >> + memcpy(val, &id, 5); >> + break; >> + default: > > Is it dangerous to return indeterminate data here? Might want to at > least zero it out. > >> + break; >> + } >> + return 0; >> +} >> + >> +static int altera_epcq_write_erase_check(struct spi_nor *nor, >> + bool write_erase) >> +{ >> + struct altera_epcq_flash *flash = nor->priv; >> + struct altera_epcq *dev = flash->priv; >> + u32 val; >> + u32 mask; >> + >> + if (write_erase) >> + mask = EPCQ_ISR_ILLEGAL_WRITE_MASK; >> + else >> + mask = EPCQ_ISR_ILLEGAL_ERASE_MASK; >> + >> + val = readl(dev->csr_base + EPCQ_ISR_REG); >> + if (val & mask) { >> + dev_err(nor->dev, >> + "write/erase failed, sector might be protected\n"); >> + /* clear this status for next use */ >> + writel(val, dev->csr_base + EPCQ_ISR_REG); >> + return -EIO; >> + } >> + return 0; >> +} >> + >> +static int altera_epcq_addr_to_sector(struct mtd_info *mtd, int offset) >> +{ >> + if (mtd->erasesize_shift) > > Is mtd->erasesize_shift ever zero for you? > >> + return offset >> mtd->erasesize_shift; >> + do_div(offset, mtd->erasesize); >> + return offset; >> +} >> + >> +static int altera_epcq_erase(struct spi_nor *nor, loff_t offset) >> +{ >> + >> + struct altera_epcq_flash *flash = nor->priv; >> + struct altera_epcq *dev = flash->priv; >> + struct mtd_info *mtd = &flash->mtd; >> + u32 val; >> + int ret; >> + int sector_value; >> + >> + ret = nor->wait_till_ready(nor); > > wait_till_ready() doesn't exist any more. And you shouldn't need to call > it here. > >> + if (ret) >> + return ret; >> + >> + sector_value = altera_epcq_addr_to_sector(mtd, offset); >> + /* sanity check that block_offset is a valid sector number */ >> + if (sector_value < 0) >> + return -EINVAL; >> + >> + /* sector value should occupy bits 17:8 */ >> + val = (sector_value << 8) & EPCQ_MEM_OP_SECTOR_VALUE_MASK; >> + >> + /* sector erase commands occupies lower 2 bits */ >> + val |= EPCQ_MEM_OP_SECTOR_ERASE_CMD; >> + >> + /* write sector erase command to EPCQ_MEM_OP register */ >> + writel(val, dev->csr_base + EPCQ_MEM_OP_REG); >> + >> + /* wait the erase command is done then check whether >> + * write triggered a illegal write interrupt >> + */ >> + ret = nor->wait_till_ready(nor); >> + if (ret) >> + return ret; >> + >> + ret = altera_epcq_write_erase_check(nor, 0); > > This function looks like it's doing interrupt-based error reporting. > Do you have an IRQ you should be requesting for this driver? It seems > like you should be doing the following sequence: > > 1. begin write/erase > 2. wait for an interrupt to signal completion > 3. check interrupt status register for erase/write failure (e.g., locked > block) > 4. return to spi-nor layer, which will read the flash status register > > That way, you don't have to use the spi-nor "wait till ready" helpers, > which really aren't suited for this. > There is no completion interrupt status register in this controller. So i just checked again with hardware engineer. The illegal write/erase interrupt status register can be read right after write/erase operation. Hence, i will remove all the wait ready functions. >> + if (ret < 0) >> + return ret; >> + >> + return 0; >> +} >> + >> +static int altera_epcq_read(struct spi_nor *nor, loff_t from, size_t len, >> + size_t *retlen, u_char *buf) >> +{ >> + struct altera_epcq_flash *flash = nor->priv; >> + struct altera_epcq *dev = flash->priv; >> + int ret = 0; >> + >> + mutex_lock(&flash->lock); > > Hmm, why do you need this lock? I think spi-nor.c will do the per-flash > locking for you, so you can remove flash->lock throughout this driver. > >> + /* wait till previous write/erase is done. */ >> + ret = nor->wait_till_ready(nor); > > Drop this. > >> + if (ret) >> + goto err; >> + >> + memcpy_fromio(buf, dev->data_base + from, len); >> + *retlen = len; >> + >> +err: >> + mutex_unlock(&flash->lock); >> + return ret; >> +} >> + >> +static void altera_epcq_write(struct spi_nor *nor, loff_t to, size_t len, >> + size_t *retlen, const u_char *buf) >> +{ >> + struct altera_epcq_flash *flash = nor->priv; >> + struct altera_epcq *dev = flash->priv; >> + int ret = 0; >> + >> + mutex_lock(&flash->lock); >> + >> + /* wait until finished previous write command */ >> + ret = nor->wait_till_ready(nor); > > Drop this. (Same throughout. I'll probably stop commenting.) > >> + if (ret) >> + goto err; >> + >> + memcpy_toio(dev->data_base + to, buf, len); >> + *retlen += len; >> + >> + /* wait until finished write command then >> + * check whether write triggered a illegal write interrupt >> + */ >> + ret = nor->wait_till_ready(nor); >> + if (ret) >> + goto err; >> + >> + ret = altera_epcq_write_erase_check(nor, 1); > > Same comments as in the erase function. You probably need to do some > sort of interrupt handling, or else you'll need to handle the above > "wait_till_ready()" some other way. > >> + if (ret < 0) >> + goto err; >> + >> +err: >> + mutex_unlock(&flash->lock); >> +} >> + >> +static int altera_epcq_lock(struct spi_nor *nor, loff_t ofs, uint64_t len) >> +{ >> + struct altera_epcq_flash *flash = nor->priv; >> + struct altera_epcq *dev = flash->priv; >> + struct mtd_info *mtd = &flash->mtd; >> + uint32_t offset = ofs; >> + int ret = 0; >> + u32 sector_start, sector_end; >> + u32 num_sectors; >> + u32 mem_op; >> + u32 sr_bp; >> + u32 sr_tb; >> + >> + sector_start = offset; >> + sector_end = altera_epcq_addr_to_sector(mtd, offset + len); >> + num_sectors = mtd->size; >> + do_div(num_sectors, mtd->erasesize); >> + >> + dev_dbg(nor->dev, "%s: sector start is %u,sector end is %u\n", >> + __func__, sector_start, sector_end); >> + >> + mutex_lock(&flash->lock); >> + /* wait until finished previous write command. */ >> + ret = nor->wait_till_ready(nor); >> + if (ret) >> + goto err; >> + >> + if (sector_start >= num_sectors / 2) { >> + sr_bp = fls(num_sectors - 1 - sector_start) + 1; >> + sr_tb = 0; >> + } else if ((sector_end < num_sectors / 2) && ~dev->is_epcs) { >> + sr_bp = fls(sector_end) + 1; >> + sr_tb = 1; >> + } else { >> + sr_bp = 16; >> + sr_tb = 0; >> + } >> + >> + mem_op = (sr_tb << 12) | (sr_bp << 8); >> + mem_op &= EPCQ_MEM_OP_SECTOR_PROTECT_VALUE_MASK; >> + mem_op |= EPCQ_MEM_OP_SECTOR_PROTECT_CMD; >> + writel(mem_op, dev->csr_base + EPCQ_MEM_OP_REG); >> + >> +err: >> + mutex_unlock(&flash->lock); >> + return ret; >> +} >> + >> +static int altera_epcq_unlock(struct spi_nor *nor, loff_t ofs, uint64_t len) >> +{ >> + struct altera_epcq_flash *flash = nor->priv; >> + struct altera_epcq *dev = flash->priv; >> + int ret = 0; >> + u32 mem_op; >> + >> + mutex_lock(&flash->lock); >> + /* wait until finished previous write command. */ >> + ret = nor->wait_till_ready(nor); >> + if (ret) >> + goto err; >> + dev_info(nor->dev, "Unlock all protected area\n"); >> + mem_op = 0; >> + mem_op &= EPCQ_MEM_OP_SECTOR_PROTECT_VALUE_MASK; >> + mem_op |= EPCQ_MEM_OP_SECTOR_PROTECT_CMD; >> + writel(mem_op, dev->csr_base + EPCQ_MEM_OP_REG); >> + >> +err: >> + mutex_unlock(&flash->lock); >> + return ret; >> +} >> + >> +static void altera_epcq_chip_select(struct altera_epcq *dev, u32 bank) >> +{ >> + u32 val = 0; >> + >> + switch (bank) { >> + case 0: >> + val = EPCQ_CHIP_SELECT_0; >> + break; >> + case 1: >> + val = EPCQ_CHIP_SELECT_1; >> + break; >> + case 2: >> + val = EPCQ_CHIP_SELECT_2; >> + break; >> + default: >> + return; >> + } >> + writel(val, dev->csr_base + EPCQ_CHIP_SELECT_REG); >> +} >> + >> + >> +static int altera_epcq_probe_config_dt(struct platform_device *pdev, >> + struct device_node *np, >> + struct altera_epcq_plat_data *pdata) >> +{ >> + struct device_node *pp = NULL; >> + struct resource *epcq_res; >> + int i = 0; >> + >> + pdata->is_epcs = of_property_read_bool(np, "is-epcs"); >> + >> + epcq_res = platform_get_resource_byname(pdev, IORESOURCE_MEM, >> + "csr_base"); >> + pdata->csr_base = devm_ioremap_resource(&pdev->dev, epcq_res); >> + if (IS_ERR(pdata->csr_base)) { >> + dev_err(&pdev->dev, "%s: ERROR: failed to map csr base\n", >> + __func__); >> + return PTR_ERR(pdata->csr_base); >> + } >> + >> + epcq_res = platform_get_resource_byname(pdev, IORESOURCE_MEM, >> + "data_base"); >> + pdata->data_base = devm_ioremap_resource(&pdev->dev, epcq_res); >> + if (IS_ERR(pdata->data_base)) { >> + dev_err(&pdev->dev, "%s: ERROR: failed to map data base\n", >> + __func__); >> + return PTR_ERR(pdata->data_base); >> + } >> + >> + /* Fill structs for each subnode (flash device) */ >> + for_each_available_child_of_node(np, pp) { >> + /* Read bank id from DT */ >> + pdata->np[i] = pp; >> + i++; >> + } >> + pdata->num_flashes = i; >> + return 0; >> +} >> + >> +static int altera_epcq_setup_banks(struct platform_device *pdev, >> + u32 bank, struct device_node *np) >> +{ >> + struct altera_epcq *dev = platform_get_drvdata(pdev); >> + struct mtd_part_parser_data ppdata = {}; >> + struct altera_epcq_flash *flash; >> + struct spi_nor *nor; >> + int ret = 0; >> + char modalias[40]; >> + >> + altera_epcq_chip_select(dev, bank); >> + >> + if (bank > dev->num_flashes - 1) >> + return -EINVAL; >> + >> + flash = devm_kzalloc(&pdev->dev, sizeof(*flash), GFP_KERNEL); >> + if (!flash) >> + return -ENOMEM; >> + >> + mutex_init(&flash->lock); >> + >> + dev->flash[bank] = flash; >> + nor = &flash->nor; >> + nor->mtd = &flash->mtd; >> + nor->dev = &pdev->dev; >> + nor->priv = flash; >> + flash->mtd.priv = nor; >> + flash->priv = dev; >> + >> + /* spi nor framework*/ >> + nor->read_reg = altera_epcq_read_reg; >> + nor->write_reg = altera_epcq_write_reg; >> + nor->read = altera_epcq_read; >> + nor->write = altera_epcq_write; >> + nor->erase = altera_epcq_erase; >> + nor->_lock = altera_epcq_lock; >> + nor->_unlock = altera_epcq_unlock; >> + >> + if (of_modalias_node(np, modalias, sizeof(modalias)) < 0) >> + return -EINVAL; >> + >> + ret = spi_nor_scan(nor, modalias, SPI_NOR_QUAD); >> + if (ret) >> + return ret; >> + ppdata.of_node = np; >> + >> + return mtd_device_parse_register(&flash->mtd, NULL, &ppdata, NULL, 0); >> +} >> + >> +static int altera_epcq_probe(struct platform_device *pdev) >> +{ >> + struct device_node *np = pdev->dev.of_node; >> + struct altera_epcq_plat_data *pdata = NULL; >> + struct altera_epcq *dev; >> + int ret = 0; >> + int i; >> + >> + if (!np) { >> + ret = -ENODEV; >> + dev_err(&pdev->dev, "no device found\n"); >> + goto err; >> + } >> + >> + pdata = devm_kzalloc(&pdev->dev, >> + sizeof(struct altera_epcq_plat_data), >> + GFP_KERNEL); >> + >> + if (!pdata) { >> + ret = -ENOMEM; >> + goto err; >> + } >> + >> + ret = altera_epcq_probe_config_dt(pdev, np, pdata); >> + if (ret) { >> + ret = -ENODEV; >> + dev_err(&pdev->dev, "probe fail\n"); >> + goto err; >> + } >> + >> + dev = devm_kzalloc(&pdev->dev, sizeof(*dev), GFP_ATOMIC); >> + if (!dev) { >> + ret = -ENOMEM; >> + goto err; >> + } >> + mutex_init(&dev->lock); >> + dev->is_epcs = pdata->is_epcs; >> + dev->csr_base = pdata->csr_base; >> + dev->data_base = pdata->data_base; >> + >> + /* check number of flashes */ >> + dev->num_flashes = pdata->num_flashes; >> + if (dev->num_flashes > MAX_NUM_FLASH_CHIP) { >> + dev_err(&pdev->dev, "exceeding max number of flashes\n"); >> + dev->num_flashes = MAX_NUM_FLASH_CHIP; >> + } >> + >> + /* check clock */ >> + dev->clk = devm_clk_get(&pdev->dev, NULL); >> + if (IS_ERR(dev->clk)) { >> + ret = PTR_ERR(dev->clk); >> + goto err; >> + } >> + ret = clk_prepare_enable(dev->clk); >> + if (ret) >> + goto err; >> + >> + platform_set_drvdata(pdev, dev); >> + >> + /* loop for each flash which is connected to epcq */ >> + for (i = 0; i < dev->num_flashes; i++) { > > I'm curious: are you doing any tests with multiple flashes > simultaneously? > >> + ret = altera_epcq_setup_banks(pdev, i, pdata->np[i]); >> + if (ret) { >> + dev_err(&pdev->dev, "bank setup failed\n"); >> + goto err_bank_setup; >> + } >> + } >> + >> + return 0; >> + >> +err_bank_setup: >> + clk_disable_unprepare(dev->clk); >> +err: >> + return ret; >> +} >> + >> +static int altera_epcq_remove(struct platform_device *pdev) >> +{ >> + struct altera_epcq *dev; >> + struct altera_epcq_flash *flash; >> + int ret, i; >> + >> + dev = platform_get_drvdata(pdev); >> + >> + /* clean up for all nor flash */ >> + for (i = 0; i < dev->num_flashes; i++) { >> + flash = dev->flash[i]; >> + if (!flash) >> + continue; >> + >> + /* clean up mtd stuff */ >> + ret = mtd_device_unregister(&flash->mtd); >> + if (ret) >> + dev_err(&pdev->dev, "error removing mtd\n"); >> + } >> + >> + clk_disable_unprepare(dev->clk); >> + >> + return 0; >> +} >> + >> +static const struct of_device_id altera_epcq_id_table[] = { >> + { .compatible = "altr,epcq-1.0" }, >> + {} >> +}; >> +MODULE_DEVICE_TABLE(of, altera_epcq_id_table); >> + >> +static struct platform_driver altera_epcq_driver = { >> + .driver = { >> + .name = ALTERA_EPCQ_RESOURCE_NAME, >> + .bus = &platform_bus_type, >> + .of_match_table = altera_epcq_id_table, >> + }, >> + .probe = altera_epcq_probe, >> + .remove = altera_epcq_remove, >> +}; >> +module_platform_driver(altera_epcq_driver); >> + >> +MODULE_AUTHOR("Viet Nga Dao "); >> +MODULE_DESCRIPTION("Altera EPCQ Driver"); >> +MODULE_LICENSE("GPL v2"); >> diff --git a/drivers/mtd/spi-nor/altera_epcq.h >> b/drivers/mtd/spi-nor/altera_epcq.h >> new file mode 100644 >> index 0000000..bc29f65 >> --- /dev/null >> +++ b/drivers/mtd/spi-nor/altera_epcq.h > > Do you need this to be a separate header? From what I can tell, it's all > private to the driver. So it may be better to merge the two. > > [snip] > >> diff --git a/drivers/mtd/spi-nor/spi-nor.c b/drivers/mtd/spi-nor/spi-nor.c >> index 3b8a411..bfbb274 100644 >> --- a/drivers/mtd/spi-nor/spi-nor.c >> +++ b/drivers/mtd/spi-nor/spi-nor.c >> @@ -330,7 +330,7 @@ erase_err: >> return ret; >> } >> >> -static int spi_nor_lock(struct mtd_info *mtd, loff_t ofs, uint64_t len) >> +static int stmicro_spi_nor_lock(struct mtd_info *mtd, loff_t ofs, uint64_t len) >> { >> struct spi_nor *nor = mtd_to_spi_nor(mtd); >> uint32_t offset = ofs; >> @@ -377,7 +377,8 @@ err: >> return ret; >> } >> >> -static int spi_nor_unlock(struct mtd_info *mtd, loff_t ofs, uint64_t len) >> +static int stmicro_spi_nor_unlock(struct mtd_info *mtd, loff_t ofs, >> + uint64_t len) >> { >> struct spi_nor *nor = mtd_to_spi_nor(mtd); >> uint32_t offset = ofs; >> @@ -424,6 +425,48 @@ err: >> return ret; >> } >> >> +static int spi_nor_lock(struct mtd_info *mtd, loff_t ofs, uint64_t len) >> +{ >> + struct spi_nor *nor = mtd_to_spi_nor(mtd); >> + int ret = 0; >> + >> + ret = spi_nor_lock_and_prep(nor, SPI_NOR_OPS_LOCK); >> + if (ret) >> + return ret; >> + >> + /* Wait until finished previous command */ >> + ret = wait_till_ready(nor); >> + if (ret) >> + goto err; >> + >> + ret = nor->_lock(nor, ofs, len); >> + >> +err: >> + spi_nor_unlock_and_unprep(nor, SPI_NOR_OPS_LOCK); >> + return ret; >> +} >> + >> +static int spi_nor_unlock(struct mtd_info *mtd, loff_t ofs, uint64_t len) >> +{ >> + struct spi_nor *nor = mtd_to_spi_nor(mtd); >> + int ret = 0; >> + >> + ret = spi_nor_lock_and_prep(nor, SPI_NOR_OPS_LOCK); >> + if (ret) >> + return ret; >> + >> + /* Wait until finished previous command */ >> + ret = wait_till_ready(nor); >> + if (ret) >> + goto err; >> + >> + ret = nor->_unlock(nor, ofs, len); >> + >> +err: >> + spi_nor_unlock_and_unprep(nor, SPI_NOR_OPS_LOCK); >> + return ret; >> +} >> + >> struct flash_info { >> /* JEDEC id zero means "no ID" (most older chips); otherwise it has >> * a high byte of zero plus three data bytes: the manufacturer id, > ... >> @@ -904,7 +977,8 @@ static void spi_nor_shutdown(struct spi_nor *nor) >> static int spi_nor_check(struct spi_nor *nor) >> { >> if (!nor->dev || !nor->read || !nor->write || >> - !nor->read_reg || !nor->write_reg || !nor->erase) { >> + !nor->read_reg || !nor->write_reg || !nor->erase || >> + !nor->_lock || !nor->_unlock) { > > No, lock() and unlock() are optional and should not be required here. > >> pr_err("spi-nor: please fill all the necessary fields!\n"); >> return -EINVAL; >> } > [...] >> @@ -987,6 +1060,9 @@ int spi_nor_scan(struct spi_nor *nor, const char >> *name, enum read_mode mode) >> >> /* nor protection support for STmicro chips */ >> if (JEDEC_MFR(info->jedec_id) == CFI_MFR_ST) { >> + mtd->_lock = stmicro_spi_nor_lock; >> + mtd->_unlock = stmicro_spi_nor_unlock; >> + } else { >> mtd->_lock = spi_nor_lock; >> mtd->_unlock = spi_nor_unlock; >> } > > No, you can't just magically create a lock() and unlock() function for > all non-ST flash here. You need to only assign this when you *know* the > flash supports lock/unlock. > >> diff --git a/include/linux/mtd/spi-nor.h b/include/linux/mtd/spi-nor.h >> index 29d1a0d..042bed2 100644 >> --- a/include/linux/mtd/spi-nor.h >> +++ b/include/linux/mtd/spi-nor.h >> @@ -183,7 +183,8 @@ struct spi_nor { >> void (*write)(struct spi_nor *nor, loff_t to, >> size_t len, size_t *retlen, const u_char *write_buf); >> int (*erase)(struct spi_nor *nor, loff_t offs); >> - >> + int (*_lock)(struct spi_nor *nor, loff_t offs, uint64_t len); >> + int (*_unlock)(struct spi_nor *nor, loff_t offs, uint64_t len); > > You need to document new fields in the comments. > >> void *priv; >> }; >> > > All in all, I think your spi-nor lock/unlock changes should be rewritten > a bit to be safer (i.e., apply only to flash that support it) and to > require less duplication (particularly on the locking). How about the > following? I've only compile-tested it, but it should now allow you to > supply nor->flash_lock() and nor->flash_unlock() implementations in your > driver. > > diff --git a/drivers/mtd/spi-nor/spi-nor.c b/drivers/mtd/spi-nor/spi-nor.c > index b6a5a0c269e1..60bf3caf1ead 100644 > --- a/drivers/mtd/spi-nor/spi-nor.c > +++ b/drivers/mtd/spi-nor/spi-nor.c > @@ -369,17 +369,13 @@ erase_err: > return ret; > } > > -static int spi_nor_lock(struct mtd_info *mtd, loff_t ofs, uint64_t len) > +static int stm_lock(struct spi_nor *nor, loff_t ofs, uint64_t len) > { > - struct spi_nor *nor = mtd_to_spi_nor(mtd); > + struct mtd_info *mtd = nor->mtd; > uint32_t offset = ofs; > uint8_t status_old, status_new; > int ret = 0; > > - ret = spi_nor_lock_and_prep(nor, SPI_NOR_OPS_LOCK); > - if (ret) > - return ret; > - > status_old = read_sr(nor); > > if (offset < mtd->size - (mtd->size / 2)) > @@ -402,26 +398,18 @@ static int spi_nor_lock(struct mtd_info *mtd, loff_t ofs, uint64_t len) > (status_old & (SR_BP2 | SR_BP1 | SR_BP0))) { > write_enable(nor); > ret = write_sr(nor, status_new); > - if (ret) > - goto err; > } > > -err: > - spi_nor_unlock_and_unprep(nor, SPI_NOR_OPS_LOCK); > return ret; > } > > -static int spi_nor_unlock(struct mtd_info *mtd, loff_t ofs, uint64_t len) > +static int stm_unlock(struct spi_nor *nor, loff_t ofs, uint64_t len) > { > - struct spi_nor *nor = mtd_to_spi_nor(mtd); > + struct mtd_info *mtd = nor->mtd; > uint32_t offset = ofs; > uint8_t status_old, status_new; > int ret = 0; > > - ret = spi_nor_lock_and_prep(nor, SPI_NOR_OPS_UNLOCK); > - if (ret) > - return ret; > - > status_old = read_sr(nor); > > if (offset+len > mtd->size - (mtd->size / 64)) > @@ -444,15 +432,41 @@ static int spi_nor_unlock(struct mtd_info *mtd, loff_t ofs, uint64_t len) > (status_old & (SR_BP2 | SR_BP1 | SR_BP0))) { > write_enable(nor); > ret = write_sr(nor, status_new); > - if (ret) > - goto err; > } > > -err: > + return ret; > +} > + > +static int spi_nor_lock(struct mtd_info *mtd, loff_t ofs, uint64_t len) > +{ > + struct spi_nor *nor = mtd_to_spi_nor(mtd); > + int ret; > + > + ret = spi_nor_lock_and_prep(nor, SPI_NOR_OPS_LOCK); > + if (ret) > + return ret; > + > + ret = nor->flash_lock(nor, ofs, len); > + > spi_nor_unlock_and_unprep(nor, SPI_NOR_OPS_UNLOCK); > return ret; > } > > +static int spi_nor_unlock(struct mtd_info *mtd, loff_t ofs, uint64_t len) > +{ > + struct spi_nor *nor = mtd_to_spi_nor(mtd); > + int ret; > + > + ret = spi_nor_lock_and_prep(nor, SPI_NOR_OPS_UNLOCK); > + if (ret) > + return ret; > + > + ret = nor->flash_unlock(nor, ofs, len); > + > + spi_nor_unlock_and_unprep(nor, SPI_NOR_OPS_LOCK); > + return ret; > +} > + > /* Used when the "_ext_id" is two bytes at most */ > #define INFO(_jedec_id, _ext_id, _sector_size, _n_sectors, _flags) \ > ((kernel_ulong_t)&(struct flash_info) { \ > @@ -1045,6 +1059,11 @@ int spi_nor_scan(struct spi_nor *nor, const char *name, enum read_mode mode) > > /* nor protection support for STmicro chips */ > if (JEDEC_MFR(info) == CFI_MFR_ST) { > + nor->flash_lock = stm_lock; > + nor->flash_unlock = stm_unlock; > + } > + > + if (nor->flash_lock && nor->flash_unlock) { > mtd->_lock = spi_nor_lock; > mtd->_unlock = spi_nor_unlock; > } > diff --git a/include/linux/mtd/spi-nor.h b/include/linux/mtd/spi-nor.h > index 4720b86ee73d..e5409524bb0a 100644 > --- a/include/linux/mtd/spi-nor.h > +++ b/include/linux/mtd/spi-nor.h > @@ -155,6 +155,8 @@ enum spi_nor_option_flags { > * @write: [DRIVER-SPECIFIC] write data to the SPI NOR > * @erase: [DRIVER-SPECIFIC] erase a sector of the SPI NOR > * at the offset @offs > + * @lock: [FLASH-SPECIFIC] lock a region of the SPI NOR > + * @unlock: [FLASH-SPECIFIC] unlock a region of the SPI NOR > * @priv: the private data > */ > struct spi_nor { > @@ -189,6 +191,9 @@ struct spi_nor { > size_t len, size_t *retlen, const u_char *write_buf); > int (*erase)(struct spi_nor *nor, loff_t offs); > > + int (*flash_lock)(struct spi_nor *nor, loff_t ofs, uint64_t len); > + int (*flash_unlock)(struct spi_nor *nor, loff_t ofs, uint64_t len); > + > void *priv; > }; >