From: Oliver Schinagl <[email protected]> Allwinner A10 and A20 ARM SoCs have an AHCI sata controller which needs 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 allows drivers to override ahci_start_engine behavior for use by the Allwinner AHCI driver (and potentially other drivers in the future). Signed-off-by: Hans de Goede <[email protected]> --- drivers/ata/ahci.h | 2 ++ drivers/ata/libahci.c | 6 ++++++ 2 files changed, 8 insertions(+) diff --git a/drivers/ata/ahci.h b/drivers/ata/ahci.h index 2289efd..8f60f33 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 ahci_start_engine override */ + void (*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..f6eabbc 100644 --- a/drivers/ata/libahci.c +++ b/drivers/ata/libahci.c @@ -568,8 +568,14 @@ 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->start_engine) { + hpriv->start_engine(ap); + return; + } + /* start DMA */ tmp = readl(port_mmio + PORT_CMD); tmp |= PORT_CMD_START; -- 1.8.4.2 -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
