Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933953AbaJUV4N (ORCPT ); Tue, 21 Oct 2014 17:56:13 -0400 Received: from down.free-electrons.com ([37.187.137.238]:52048 "EHLO mail.free-electrons.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S933686AbaJUV4I (ORCPT ); Tue, 21 Oct 2014 17:56:08 -0400 From: Alexandre Belloni To: Nicolas Ferre , Sebastian Reichel Cc: Jean-Christophe Plagniol-Villard , Dmitry Eremin-Solenikov , David Woodhouse , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org, Alexandre Belloni Subject: [PATCH 1/8] memory: atmel-sdramc: export a shutdown function Date: Tue, 21 Oct 2014 23:55:33 +0200 Message-Id: <1413928540-27099-2-git-send-email-alexandre.belloni@free-electrons.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1413928540-27099-1-git-send-email-alexandre.belloni@free-electrons.com> References: <1413928540-27099-1-git-send-email-alexandre.belloni@free-electrons.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org It is necessary to shutdown the SDRAM before resetting the SoC to avoid having issue with NAND boot. Export a function that does exactly that. Signed-off-by: Alexandre Belloni --- drivers/memory/atmel-sdramc.c | 90 +++++++++++++++++++++++++++++++++++++++++++ include/soc/atmel/memory.h | 6 +++ 2 files changed, 96 insertions(+) create mode 100644 include/soc/atmel/memory.h diff --git a/drivers/memory/atmel-sdramc.c b/drivers/memory/atmel-sdramc.c index fed04e8efe75..148906dabe55 100644 --- a/drivers/memory/atmel-sdramc.c +++ b/drivers/memory/atmel-sdramc.c @@ -21,24 +21,101 @@ #include #include #include +#include #include #include +#include + +#define AT91_SDRAMC_TR 0x04 /* SDRAM Controller Refresh Timer Register */ +#define AT91_SDRAMC_LPR 0x10 /* SDRAM Controller Low Power Register */ +#define AT91_SDRAMC_LPCB_POWER_DOWN 2 + +#define AT91_DDRSDRC_RTR 0x04 /* Refresh Timer Register */ +#define AT91_DDRSDRC_LPR 0x1C /* Low Power Register */ +#define AT91_DDRSDRC_LPCB_POWER_DOWN 2 + +static void __iomem *at91_ramc_base[2]; + +void (*at91_ramc_shutdown)(void); + struct at91_ramc_caps { bool has_ddrck; bool has_mpddr_clk; + void (*shutdown)(void); }; +void at91sam9260_shutdown(void) +{ + pr_err("%s +%d %s\n", __FILE__, __LINE__, __func__); + asm volatile( + /* Align to cache lines */ + ".balign 32\n\t" + + /* Disable SDRAM accesses */ + "str %1, [%0, #" __stringify(AT91_SDRAMC_TR) "]\n\t" + + /* Power down SDRAM */ + "str %2, [%0, #" __stringify(AT91_SDRAMC_LPR) "]\n\t" + + : + : "r" (at91_ramc_base[0]), + "r" (1), + "r" (AT91_SDRAMC_LPCB_POWER_DOWN)); +} + +void at91sam9g45_shutdown(void) +{ + asm volatile( + /* + * Test wether we have a second RAM controller to care + * about. + * + * First, test that we can dereference the virtual address. + */ + "cmp %1, #0\n\t" + "beq 1f\n\t" + + /* Then, test that the RAM controller is enabled */ + "ldr r0, [%1]\n\t" + "cmp r0, #0\n\t" + + /* Align to cache lines */ + ".balign 32\n\t" + + /* Disable SDRAM0 accesses */ + "1: str %2, [%0, #" __stringify(AT91_DDRSDRC_RTR) "]\n\t" + /* Power down SDRAM0 */ + " str %3, [%0, #" __stringify(AT91_DDRSDRC_LPR) "]\n\t" + /* Disable SDRAM1 accesses */ + " strne %2, [%1, #" __stringify(AT91_DDRSDRC_RTR) "]\n\t" + /* Power down SDRAM1 */ + " strne %3, [%1, #" __stringify(AT91_DDRSDRC_LPR) "]\n\t" + + : + : "r" (at91_ramc_base[0]), + "r" (at91_ramc_base[1]), + "r" (1), + "r" (AT91_DDRSDRC_LPCB_POWER_DOWN) + : "r0"); +} + static const struct at91_ramc_caps at91rm9200_caps = { }; +static const struct at91_ramc_caps at91sam9260_caps = { + .shutdown = at91sam9260_shutdown, +}; + static const struct at91_ramc_caps at91sam9g45_caps = { .has_ddrck = 1, .has_mpddr_clk = 0, + .shutdown = at91sam9g45_shutdown, }; static const struct at91_ramc_caps sama5d3_caps = { .has_ddrck = 1, .has_mpddr_clk = 1, + .shutdown = at91sam9g45_shutdown, }; static const struct of_device_id atmel_ramc_of_match[] = { @@ -54,7 +131,9 @@ static int atmel_ramc_probe(struct platform_device *pdev) { const struct of_device_id *match; const struct at91_ramc_caps *caps; + struct device_node *np; struct clk *clk; + int idx = 0; match = of_match_device(atmel_ramc_of_match, &pdev->dev); caps = match->data; @@ -75,6 +154,17 @@ static int atmel_ramc_probe(struct platform_device *pdev) clk_prepare_enable(clk); } + for_each_matching_node(np, atmel_ramc_of_match) { + at91_ramc_base[idx] = of_iomap(np, 0); + if (!at91_ramc_base[idx]) { + dev_err(&pdev->dev, "Could not map ram controller address\n"); + return -ENODEV; + } + idx++; + } + + at91_ramc_shutdown = caps->shutdown; + return 0; } diff --git a/include/soc/atmel/memory.h b/include/soc/atmel/memory.h new file mode 100644 index 000000000000..04cc1261e636 --- /dev/null +++ b/include/soc/atmel/memory.h @@ -0,0 +1,6 @@ +#ifndef __INCLUDE_ATMEL_MEMORY_H +#define __INCLUDE_ATMEL_MEMORY_H + +extern void (*at91_ramc_shutdown)(void); + +#endif /* __INCLUDE_ATMEL_MEMORY_H */ -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/