From mboxrd@z Thu Jan 1 00:00:00 1970 From: Shawn Guo Subject: [PATCH v3 08/10] ARM: mxs: add ocotp read function Date: Wed, 5 Jan 2011 22:07:35 +0800 Message-ID: <1294236457-17476-9-git-send-email-shawn.guo@freescale.com> References: <1294236457-17476-1-git-send-email-shawn.guo@freescale.com> Mime-Version: 1.0 Content-Type: text/plain Cc: Shawn Guo To: , , , , , , , Received: from am1ehsobe002.messaging.microsoft.com ([213.199.154.205]:58084 "EHLO AM1EHSOBE002.bigfish.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751483Ab1AEOGe (ORCPT ); Wed, 5 Jan 2011 09:06:34 -0500 In-Reply-To: <1294236457-17476-1-git-send-email-shawn.guo@freescale.com> Sender: netdev-owner@vger.kernel.org List-ID: Signed-off-by: Shawn Guo --- Changes for v2: - Add mutex locking for mxs_read_ocotp() - Use type size_t for count and i - Add comment for clk_enable/disable skipping - Add ERROR bit clearing and polling step arch/arm/mach-mxs/Makefile | 2 +- arch/arm/mach-mxs/include/mach/common.h | 1 + arch/arm/mach-mxs/ocotp.c | 79 +++++++++++++++++++++++++++++++ 3 files changed, 81 insertions(+), 1 deletions(-) create mode 100644 arch/arm/mach-mxs/ocotp.c diff --git a/arch/arm/mach-mxs/Makefile b/arch/arm/mach-mxs/Makefile index 39d3f9c..f23ebbd 100644 --- a/arch/arm/mach-mxs/Makefile +++ b/arch/arm/mach-mxs/Makefile @@ -1,5 +1,5 @@ # Common support -obj-y := clock.o devices.o gpio.o icoll.o iomux.o system.o timer.o +obj-y := clock.o devices.o gpio.o icoll.o iomux.o ocotp.o system.o timer.o obj-$(CONFIG_SOC_IMX23) += clock-mx23.o mm-mx23.o obj-$(CONFIG_SOC_IMX28) += clock-mx28.o mm-mx28.o diff --git a/arch/arm/mach-mxs/include/mach/common.h b/arch/arm/mach-mxs/include/mach/common.h index 59133eb..cf02552 100644 --- a/arch/arm/mach-mxs/include/mach/common.h +++ b/arch/arm/mach-mxs/include/mach/common.h @@ -13,6 +13,7 @@ struct clk; +extern int mxs_read_ocotp(int offset, int count, u32 *values); extern int mxs_reset_block(void __iomem *); extern void mxs_timer_init(struct clk *, int); diff --git a/arch/arm/mach-mxs/ocotp.c b/arch/arm/mach-mxs/ocotp.c new file mode 100644 index 0000000..902ef59 --- /dev/null +++ b/arch/arm/mach-mxs/ocotp.c @@ -0,0 +1,79 @@ +/* + * Copyright 2010 Freescale Semiconductor, Inc. All Rights Reserved. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that 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. + */ + +#include +#include +#include + +#include + +#define BM_OCOTP_CTRL_BUSY (1 << 8) +#define BM_OCOTP_CTRL_ERROR (1 << 9) +#define BM_OCOTP_CTRL_RD_BANK_OPEN (1 << 12) + +static DEFINE_MUTEX(ocotp_mutex); + +int mxs_read_ocotp(unsigned offset, size_t count, u32 *values) +{ + void __iomem *ocotp_base = MXS_IO_ADDRESS(MXS_OCOTP_BASE_ADDR); + int timeout = 0x400; + size_t i; + + mutex_lock(&ocotp_mutex); + + /* + * clk_enable(hbus_clk) for ocotp can be skipped + * as it must be on when system is running. + */ + + /* try to clear ERROR bit */ + __mxs_clrl(BM_OCOTP_CTRL_ERROR, ocotp_base); + + /* check both BUSY and ERROR cleared */ + while ((__raw_readl(ocotp_base) & + (BM_OCOTP_CTRL_BUSY | BM_OCOTP_CTRL_ERROR)) && --timeout) + /* nothing */; + + if (unlikely(!timeout)) + goto error_unlock; + + /* open OCOTP banks for read */ + __mxs_setl(BM_OCOTP_CTRL_RD_BANK_OPEN, ocotp_base); + + /* approximately wait 32 hclk cycles */ + udelay(1); + + /* poll BUSY bit becoming cleared */ + timeout = 0x400; + while ((__raw_readl(ocotp_base) & BM_OCOTP_CTRL_BUSY) && --timeout) + /* nothing */; + + if (unlikely(!timeout)) + goto error_unlock; + + for (i = 0; i < count; i++, offset += 4) + *values++ = __raw_readl(ocotp_base + offset); + + /* close banks for power saving */ + __mxs_clrl(BM_OCOTP_CTRL_RD_BANK_OPEN, ocotp_base); + + mutex_unlock(&ocotp_mutex); + + return 0; + +error_unlock: + mutex_unlock(&ocotp_mutex); + pr_err("%s: timeout in reading OCOTP\n", __func__); + return -ETIMEDOUT; +} -- 1.7.1