Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934315AbdDFJgC (ORCPT ); Thu, 6 Apr 2017 05:36:02 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:50642 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754752AbdDFIkI (ORCPT ); Thu, 6 Apr 2017 04:40:08 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Alexandre Belloni , Sebastian Reichel Subject: [PATCH 4.4 23/26] power: reset: at91-poweroff: timely shutdown LPDDR memories Date: Thu, 6 Apr 2017 10:38:45 +0200 Message-Id: <20170406083605.797902629@linuxfoundation.org> X-Mailer: git-send-email 2.12.2 In-Reply-To: <20170406083604.362636628@linuxfoundation.org> References: <20170406083604.362636628@linuxfoundation.org> User-Agent: quilt/0.65 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3600 Lines: 126 4.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Alexandre Belloni commit 0b0408745e7ff24757cbfd571d69026c0ddb803c upstream. LPDDR memories can only handle up to 400 uncontrolled power off. Ensure the proper power off sequence is used before shutting down the platform. Signed-off-by: Alexandre Belloni Signed-off-by: Sebastian Reichel Signed-off-by: Greg Kroah-Hartman --- drivers/power/reset/at91-poweroff.c | 54 +++++++++++++++++++++++++++++++++++- 1 file changed, 53 insertions(+), 1 deletion(-) --- a/drivers/power/reset/at91-poweroff.c +++ b/drivers/power/reset/at91-poweroff.c @@ -14,9 +14,12 @@ #include #include #include +#include #include #include +#include + #define AT91_SHDW_CR 0x00 /* Shut Down Control Register */ #define AT91_SHDW_SHDW BIT(0) /* Shut Down command */ #define AT91_SHDW_KEY (0xa5 << 24) /* KEY Password */ @@ -50,6 +53,7 @@ static const char *shdwc_wakeup_modes[] static void __iomem *at91_shdwc_base; static struct clk *sclk; +static void __iomem *mpddrc_base; static void __init at91_wakeup_status(void) { @@ -73,6 +77,29 @@ static void at91_poweroff(void) writel(AT91_SHDW_KEY | AT91_SHDW_SHDW, at91_shdwc_base + AT91_SHDW_CR); } +static void at91_lpddr_poweroff(void) +{ + asm volatile( + /* Align to cache lines */ + ".balign 32\n\t" + + /* Ensure AT91_SHDW_CR is in the TLB by reading it */ + " ldr r6, [%2, #" __stringify(AT91_SHDW_CR) "]\n\t" + + /* Power down SDRAM0 */ + " str %1, [%0, #" __stringify(AT91_DDRSDRC_LPR) "]\n\t" + /* Shutdown CPU */ + " str %3, [%2, #" __stringify(AT91_SHDW_CR) "]\n\t" + + " b .\n\t" + : + : "r" (mpddrc_base), + "r" cpu_to_le32(AT91_DDRSDRC_LPDDR2_PWOFF), + "r" (at91_shdwc_base), + "r" cpu_to_le32(AT91_SHDW_KEY | AT91_SHDW_SHDW) + : "r0"); +} + static int at91_poweroff_get_wakeup_mode(struct device_node *np) { const char *pm; @@ -124,6 +151,8 @@ static void at91_poweroff_dt_set_wakeup_ static int __init at91_poweroff_probe(struct platform_device *pdev) { struct resource *res; + struct device_node *np; + u32 ddr_type; int ret; res = platform_get_resource(pdev, IORESOURCE_MEM, 0); @@ -150,12 +179,30 @@ static int __init at91_poweroff_probe(st pm_power_off = at91_poweroff; + np = of_find_compatible_node(NULL, NULL, "atmel,sama5d3-ddramc"); + if (!np) + return 0; + + mpddrc_base = of_iomap(np, 0); + of_node_put(np); + + if (!mpddrc_base) + return 0; + + ddr_type = readl(mpddrc_base + AT91_DDRSDRC_MDR) & AT91_DDRSDRC_MD; + if ((ddr_type == AT91_DDRSDRC_MD_LPDDR2) || + (ddr_type == AT91_DDRSDRC_MD_LPDDR3)) + pm_power_off = at91_lpddr_poweroff; + else + iounmap(mpddrc_base); + return 0; } static int __exit at91_poweroff_remove(struct platform_device *pdev) { - if (pm_power_off == at91_poweroff) + if (pm_power_off == at91_poweroff || + pm_power_off == at91_lpddr_poweroff) pm_power_off = NULL; clk_disable_unprepare(sclk); @@ -163,6 +210,11 @@ static int __exit at91_poweroff_remove(s return 0; } +static const struct of_device_id at91_ramc_of_match[] = { + { .compatible = "atmel,sama5d3-ddramc", }, + { /* sentinel */ } +}; + static const struct of_device_id at91_poweroff_of_match[] = { { .compatible = "atmel,at91sam9260-shdwc", }, { .compatible = "atmel,at91sam9rl-shdwc", },