From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1030352AbcHaQLc (ORCPT ); Wed, 31 Aug 2016 12:11:32 -0400 Received: from down.free-electrons.com ([37.187.137.238]:40688 "EHLO mail.free-electrons.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1030318AbcHaQLY (ORCPT ); Wed, 31 Aug 2016 12:11:24 -0400 From: Alexandre Belloni To: Nicolas Ferre Cc: linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Boris Brezillon , Alexandre Belloni , Arnd Bergmann , Greg Kroah-Hartman , Philipp Zabel , Vladimir Zapolskiy Subject: [PATCH 5/5] misc: sram: add Atmel securam support Date: Wed, 31 Aug 2016 18:11:08 +0200 Message-Id: <20160831161108.8780-6-alexandre.belloni@free-electrons.com> X-Mailer: git-send-email 2.9.3 In-Reply-To: <20160831161108.8780-1-alexandre.belloni@free-electrons.com> References: <20160831161108.8780-1-alexandre.belloni@free-electrons.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The Atmel secure SRAM is connected to a security module and may be erased automatically under certain conditions. For that reason, it is necessary to wait for the security module to flag that SRAM accesses are allowed before accessing it. Signed-off-by: Alexandre Belloni --- Cc: Arnd Bergmann Cc: Greg Kroah-Hartman Cc: Philipp Zabel Cc: Vladimir Zapolskiy drivers/misc/sram.c | 52 +++++++++++++++++++++++++++++++++++++++++++++------- 1 file changed, 45 insertions(+), 7 deletions(-) diff --git a/drivers/misc/sram.c b/drivers/misc/sram.c index f84b53d6ce50..8d411c64d07f 100644 --- a/drivers/misc/sram.c +++ b/drivers/misc/sram.c @@ -19,12 +19,16 @@ */ #include +#include #include #include #include #include #include +#include #include +#include +#include #define SRAM_GRANULARITY 32 @@ -334,12 +338,43 @@ static int sram_reserve_regions(struct sram_dev *sram, struct resource *res) return ret; } +static int atmel_securam_wait(void) +{ + struct regmap *regmap; + unsigned long timeout = jiffies + HZ; + u32 val; + + regmap = syscon_regmap_lookup_by_compatible("atmel,sama5d2-secumod"); + if (IS_ERR(regmap)) + return -ENODEV; + + regmap_read(regmap, AT91_SECUMOD_RAMRDY, &val); + while (!(val & AT91_SECUMOD_RAMRDY_READY) && + time_before(jiffies, timeout)) { + mdelay(10); + regmap_read(regmap, AT91_SECUMOD_RAMRDY, &val); + } + if (!time_before(jiffies, timeout)) + return -ETIMEDOUT; + + return 0; +} + +#ifdef CONFIG_OF +static const struct of_device_id sram_dt_ids[] = { + { .compatible = "mmio-sram" }, + { .compatible = "atmel,sama5d2-securam", .data = atmel_securam_wait }, + {} +}; +#endif + static int sram_probe(struct platform_device *pdev) { struct sram_dev *sram; struct resource *res; size_t size; int ret; + const struct of_device_id *match; sram = devm_kzalloc(&pdev->dev, sizeof(*sram), GFP_KERNEL); if (!sram) @@ -384,6 +419,16 @@ static int sram_probe(struct platform_device *pdev) platform_set_drvdata(pdev, sram); + match = of_match_node(sram_dt_ids, pdev->dev.of_node); + if (match->data) { + int (*init_func)(void); + + init_func = match->data; + ret = init_func(); + if (ret) + return ret; + } + dev_dbg(sram->dev, "SRAM pool: %zu KiB @ 0x%p\n", gen_pool_size(sram->pool) / 1024, sram->virt_base); @@ -405,13 +450,6 @@ static int sram_remove(struct platform_device *pdev) return 0; } -#ifdef CONFIG_OF -static const struct of_device_id sram_dt_ids[] = { - { .compatible = "mmio-sram" }, - {} -}; -#endif - static struct platform_driver sram_driver = { .driver = { .name = "sram", -- 2.9.3