From patchwork Mon Jun 17 18:46:39 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: pekon gupta X-Patchwork-Id: 252040 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:770:15f::2]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTPS id 8E4AF2C016F for ; Tue, 18 Jun 2013 04:48:09 +1000 (EST) Received: from merlin.infradead.org ([2001:4978:20e::2]) by casper.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1UoeSl-0005iZ-6g; Mon, 17 Jun 2013 18:47:35 +0000 Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1UoeSg-0001aB-MQ; Mon, 17 Jun 2013 18:47:30 +0000 Received: from bear.ext.ti.com ([192.94.94.41]) by merlin.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1UoeSa-0001Xp-M6 for linux-mtd@lists.infradead.org; Mon, 17 Jun 2013 18:47:26 +0000 Received: from dlelxv90.itg.ti.com ([172.17.2.17]) by bear.ext.ti.com (8.13.7/8.13.7) with ESMTP id r5HIl10e010659; Mon, 17 Jun 2013 13:47:01 -0500 Received: from DFLE73.ent.ti.com (dfle73.ent.ti.com [128.247.5.110]) by dlelxv90.itg.ti.com (8.14.3/8.13.8) with ESMTP id r5HIl1om014395; Mon, 17 Jun 2013 13:47:01 -0500 Received: from dlelxv22.itg.ti.com (172.17.1.197) by DFLE73.ent.ti.com (128.247.5.110) with Microsoft SMTP Server id 14.2.342.3; Mon, 17 Jun 2013 13:47:00 -0500 Received: from psplinux064.india.ti.com (psplinux064.india.ti.com [10.24.100.118]) by dlelxv22.itg.ti.com (8.13.8/8.13.8) with ESMTP id r5HIkp5g011304; Mon, 17 Jun 2013 13:46:59 -0500 From: Pekon Gupta To: , Subject: [PATCH v5 3/3] mtd: devices: elm: Low power transition support Date: Tue, 18 Jun 2013 00:16:39 +0530 Message-ID: <1371494799-11876-4-git-send-email-pekon@ti.com> X-Mailer: git-send-email 1.8.1 In-Reply-To: <1371494799-11876-1-git-send-email-pekon@ti.com> References: <1371494799-11876-1-git-send-email-pekon@ti.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20130617_144724_839051_43A7287E X-CRM114-Status: GOOD ( 15.61 ) X-Spam-Score: -8.0 (--------) X-Spam-Report: SpamAssassin version 3.3.2 on merlin.infradead.org summary: Content analysis details: (-8.0 points) pts rule name description ---- ---------------------- -------------------------------------------------- -5.0 RCVD_IN_DNSWL_HI RBL: Sender listed at http://www.dnswl.org/, high trust [192.94.94.41 listed in list.dnswl.org] -0.0 SPF_PASS SPF: sender matches SPF record -1.1 RP_MATCHES_RCVD Envelope sender domain matches handover relay domain -1.9 BAYES_00 BODY: Bayes spam probability is 0 to 1% [score: 0.0000] Cc: tony@atomide.com, khilman@linaro.org, Pekon Gupta X-BeenThere: linux-mtd@lists.infradead.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-mtd" Errors-To: linux-mtd-bounces+incoming=patchwork.ozlabs.org@lists.infradead.org From: avinash philip ELM is used for locating bit-flip errors in when using BCH ECC scheme. This patch adds suspend/resume support for leaf level ELM driver, And also provides ELM register context save & restore support, so that configurations are preserved across hardware power-off/on transitions. Signed-off-by: Philip Avinash Signed-off-by: Pekon Gupta --- drivers/mtd/devices/elm.c | 117 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 117 insertions(+) diff --git a/drivers/mtd/devices/elm.c b/drivers/mtd/devices/elm.c index dccef9f..e6a7b89 100644 --- a/drivers/mtd/devices/elm.c +++ b/drivers/mtd/devices/elm.c @@ -20,14 +20,21 @@ #include #include #include +#include #include #include +#define ELM_SYSCONFIG 0x010 #define ELM_IRQSTATUS 0x018 #define ELM_IRQENABLE 0x01c #define ELM_LOCATION_CONFIG 0x020 #define ELM_PAGE_CTRL 0x080 #define ELM_SYNDROME_FRAGMENT_0 0x400 +#define ELM_SYNDROME_FRAGMENT_1 0x404 +#define ELM_SYNDROME_FRAGMENT_2 0x408 +#define ELM_SYNDROME_FRAGMENT_3 0x40c +#define ELM_SYNDROME_FRAGMENT_4 0x410 +#define ELM_SYNDROME_FRAGMENT_5 0x414 #define ELM_SYNDROME_FRAGMENT_6 0x418 #define ELM_LOCATION_STATUS 0x800 #define ELM_ERROR_LOCATION_0 0x880 @@ -56,12 +63,27 @@ #define SYNDROME_FRAGMENT_REG_SIZE 0x40 #define ERROR_LOCATION_SIZE 0x100 +struct elm_registers { + u32 elm_irqenable; + u32 elm_sysconfig; + u32 elm_location_config; + u32 elm_page_ctrl; + u32 elm_syndrome_fragment_6[ERROR_VECTOR_MAX]; + u32 elm_syndrome_fragment_5[ERROR_VECTOR_MAX]; + u32 elm_syndrome_fragment_4[ERROR_VECTOR_MAX]; + u32 elm_syndrome_fragment_3[ERROR_VECTOR_MAX]; + u32 elm_syndrome_fragment_2[ERROR_VECTOR_MAX]; + u32 elm_syndrome_fragment_1[ERROR_VECTOR_MAX]; + u32 elm_syndrome_fragment_0[ERROR_VECTOR_MAX]; +}; + struct elm_info { struct device *dev; void __iomem *elm_base; struct completion elm_completion; struct list_head list; enum bch_ecc bch_type; + struct elm_registers elm_regs; }; static LIST_HEAD(elm_devices); @@ -385,6 +407,100 @@ static int elm_remove(struct platform_device *pdev) return 0; } +/** + * elm_context_save + * saves ELM configurations to preserve them across Hardware powered-down + */ +static int elm_context_save(struct elm_info *info) +{ + struct elm_registers *regs = &info->elm_regs; + enum bch_ecc bch_type = info->bch_type; + u32 offset = 0, i; + + regs->elm_irqenable = elm_read_reg(info, ELM_IRQENABLE); + regs->elm_sysconfig = elm_read_reg(info, ELM_SYSCONFIG); + regs->elm_location_config = elm_read_reg(info, ELM_LOCATION_CONFIG); + regs->elm_page_ctrl = elm_read_reg(info, ELM_PAGE_CTRL); + for (i = 0; i < ERROR_VECTOR_MAX; i++) { + offset = i * SYNDROME_FRAGMENT_REG_SIZE; + switch (bch_type) { + case BCH8_ECC: + regs->elm_syndrome_fragment_3[i] = elm_read_reg(info, + ELM_SYNDROME_FRAGMENT_3 + offset); + regs->elm_syndrome_fragment_2[i] = elm_read_reg(info, + ELM_SYNDROME_FRAGMENT_2 + offset); + case BCH4_ECC: + regs->elm_syndrome_fragment_1[i] = elm_read_reg(info, + ELM_SYNDROME_FRAGMENT_1 + offset); + regs->elm_syndrome_fragment_0[i] = elm_read_reg(info, + ELM_SYNDROME_FRAGMENT_0 + offset); + default: + return -EINVAL; + } + /* ELM SYNDROME_VALID bit in SYNDROME_FRAGMENT_6[] needs + * to be saved for all BCH schemes*/ + regs->elm_syndrome_fragment_6[i] = elm_read_reg(info, + ELM_SYNDROME_FRAGMENT_6 + offset); + } + return 0; +} + +/** + * elm_context_restore + * writes configurations saved duing power-down back into ELM registers + */ +static int elm_context_restore(struct elm_info *info) +{ + struct elm_registers *regs = &info->elm_regs; + enum bch_ecc bch_type = info->bch_type; + u32 offset = 0, i; + + elm_write_reg(info, ELM_IRQENABLE, regs->elm_irqenable); + elm_write_reg(info, ELM_SYSCONFIG, regs->elm_sysconfig); + elm_write_reg(info, ELM_LOCATION_CONFIG, regs->elm_location_config); + elm_write_reg(info, ELM_PAGE_CTRL, regs->elm_page_ctrl); + for (i = 0; i < ERROR_VECTOR_MAX; i++) { + offset = i * SYNDROME_FRAGMENT_REG_SIZE; + switch (bch_type) { + case BCH8_ECC: + elm_write_reg(info, ELM_SYNDROME_FRAGMENT_3 + offset, + regs->elm_syndrome_fragment_3[i]); + elm_write_reg(info, ELM_SYNDROME_FRAGMENT_2 + offset, + regs->elm_syndrome_fragment_2[i]); + case BCH4_ECC: + elm_write_reg(info, ELM_SYNDROME_FRAGMENT_1 + offset, + regs->elm_syndrome_fragment_1[i]); + elm_write_reg(info, ELM_SYNDROME_FRAGMENT_0 + offset, + regs->elm_syndrome_fragment_0[i]); + default: + return -EINVAL; + } + /* ELM_SYNDROME_VALID bit to be set in last to trigger FSM */ + elm_write_reg(info, ELM_SYNDROME_FRAGMENT_6 + offset, + regs->elm_syndrome_fragment_6[i] & + ELM_SYNDROME_VALID); + } + return 0; +} + +static int elm_suspend(struct device *dev) +{ + struct elm_info *info = dev_get_drvdata(dev); + elm_context_save(info); + pm_runtime_put_sync(dev); + return 0; +} + +static int elm_resume(struct device *dev) +{ + struct elm_info *info = dev_get_drvdata(dev); + pm_runtime_get_sync(dev); + elm_context_restore(info); + return 0; +} + +static SIMPLE_DEV_PM_OPS(elm_pm_ops, elm_suspend, elm_resume); + #ifdef CONFIG_OF static const struct of_device_id elm_of_match[] = { { .compatible = "ti,am3352-elm" }, @@ -398,6 +514,7 @@ static struct platform_driver elm_driver = { .name = "elm", .owner = THIS_MODULE, .of_match_table = of_match_ptr(elm_of_match), + .pm = &elm_pm_ops, }, .probe = elm_probe, .remove = elm_remove,