From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sourav Poddar Subject: Re: [PATCHv2 07/10] drivers: mtd: m25p80: Adapt driver to support memory mapped read. Date: Thu, 12 Dec 2013 13:45:24 +0530 Message-ID: <52A9709C.4010606@ti.com> References: <1386339891-32717-1-git-send-email-sourav.poddar@ti.com> <1386339891-32717-8-git-send-email-sourav.poddar@ti.com> <20131212075536.GA1596@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset="ISO-8859-1"; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from bear.ext.ti.com ([192.94.94.41]:46392 "EHLO bear.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751399Ab3LLIP6 (ORCPT ); Thu, 12 Dec 2013 03:15:58 -0500 In-Reply-To: <20131212075536.GA1596@gmail.com> Sender: linux-omap-owner@vger.kernel.org List-Id: linux-omap@vger.kernel.org To: Huang Shijie Cc: broonie@kernel.org, linux-spi@vger.kernel.org, computersforpeace@gmail.com, marex@denx.de, devicetree@vger.kernel.org, balbi@ti.com, linux-mtd@lists.infradead.org, bcousson@baylibre.com, linux-omap@vger.kernel.org, dwmw2@infradead.org On Thursday 12 December 2013 01:25 PM, Huang Shijie wrote: > On Fri, Dec 06, 2013 at 07:54:48PM +0530, Sourav Poddar wrote: >> Adapt driver to do a memory mapped read. >> @@ -109,6 +109,7 @@ struct m25p { >> u8 program_opcode; >> u8 *command; >> enum read_type flash_read; >> + void __iomem *mem_addr; > I think we can remove this field. > You can use a local variable in the m25p80_read. > >> }; >> >> static inline struct m25p *mtd_to_m25p(struct mtd_info *mtd) >> @@ -515,6 +516,7 @@ static int m25p80_read(struct mtd_info *mtd, loff_t from, size_t len, >> size_t *retlen, u_char *buf) >> { >> struct m25p *flash = mtd_to_m25p(mtd); >> + struct spi_master *master = flash->spi->master; >> struct spi_transfer t[2]; >> struct spi_message m; >> uint8_t opcode; >> @@ -523,6 +525,20 @@ static int m25p80_read(struct mtd_info *mtd, loff_t from, size_t len, >> pr_debug("%s: %s from 0x%08x, len %zd\n", dev_name(&flash->spi->dev), >> __func__, (u32)from, len); >> >> + if (master->mmap) { >> + mutex_lock(&flash->lock); >> + /* Wait till previous write/erase is done. */ >> + if (wait_till_ready(flash)) { >> + mutex_unlock(&flash->lock); >> + return 1; >> + } >> + flash->mem_addr = master->get_buf(master); >> + memcpy(buf, flash->mem_addr + from, len); >> + master->put_buf(master); >> + *retlen = len; >> + goto out; >> + } >> + >> spi_message_init(&m); >> memset(t, 0, (sizeof t)); >> >> @@ -558,6 +574,7 @@ static int m25p80_read(struct mtd_info *mtd, loff_t from, size_t len, >> >> *retlen = m.actual_length - m25p_cmdsz(flash) - dummy; >> >> +out: >> mutex_unlock(&flash->lock); >> >> return 0; >> @@ -1286,6 +1303,9 @@ static int m25p_probe(struct spi_device *spi) >> flash->addr_width = 3; >> } >> >> + if (spi->master->configure_from_slave) >> + m25p80_fill_flash_information(flash); >> + > You have add a configure_from_slave hook in the SPI, why you also need > a same hook in the SPI-NOR framework? > We need a way to provoke this, currently it is placed in m25p80. If m25p80 is removed, for where should I handle these in nor framework? > And i think the enable_mmap/disable_mmap is not needed too. > > All the three hooks are used to set the SPI bus controller. > And the SPI-NOR framework only handles the issues between the > SPI bus controller and the SPI-NOR, or the SPI-NOR controller and the > SPI-NOR. My controller can be used as spi flash controller as well as a spi controller. > thanks > Huang Shijie > >