From mboxrd@z Thu Jan 1 00:00:00 1970 From: hdegoede@redhat.com (Hans de Goede) Date: Sat, 4 Jan 2014 10:14:35 +0100 Subject: [PATCH v2 1/4] libahci: Add a pre ahci_start_engine hook In-Reply-To: <1388826878-5602-1-git-send-email-hdegoede@redhat.com> References: <1388826878-5602-1-git-send-email-hdegoede@redhat.com> Message-ID: <1388826878-5602-2-git-send-email-hdegoede@redhat.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org From: Oliver Schinagl Allwinner A10 and A20 ARM SoCs have an AHCI sata controller which need a special register to be poked before starting the DMA engine. This register gets reset on an ahci_stop_engine call, so there is no other place then ahci_start_engine where this poking can be done. This commit adds a pre ahci_start_engine hook for use by the Allwinner AHCI driver (and potentially other drivers in the future). Signed-off-by: Hans de Goede --- drivers/ata/ahci.h | 2 ++ drivers/ata/libahci.c | 4 ++++ 2 files changed, 6 insertions(+) diff --git a/drivers/ata/ahci.h b/drivers/ata/ahci.h index 2289efd..1bba479 100644 --- a/drivers/ata/ahci.h +++ b/drivers/ata/ahci.h @@ -323,6 +323,8 @@ struct ahci_host_priv { u32 em_msg_type; /* EM message type */ struct clk *clk; /* Only for platforms supporting clk */ void *plat_data; /* Other platform data */ + /* Optional pre ahci_start_engine hook */ + void (*pre_start_engine)(struct ata_port *ap); }; extern int ahci_ignore_sss; diff --git a/drivers/ata/libahci.c b/drivers/ata/libahci.c index c482f8c..780e9df 100644 --- a/drivers/ata/libahci.c +++ b/drivers/ata/libahci.c @@ -568,8 +568,12 @@ static int ahci_scr_write(struct ata_link *link, unsigned int sc_reg, u32 val) void ahci_start_engine(struct ata_port *ap) { void __iomem *port_mmio = ahci_port_base(ap); + struct ahci_host_priv *hpriv = ap->host->private_data; u32 tmp; + if (hpriv->pre_start_engine) + hpriv->pre_start_engine(ap); + /* start DMA */ tmp = readl(port_mmio + PORT_CMD); tmp |= PORT_CMD_START; -- 1.8.4.2