Thread (4 messages) flat view 4 messages, 3 authors, 2014-01-05

Re: [PATCH v2 2/4] ARM: sunxi: Add ahci-sunxi driver for the Allwinner SUNXi SoCs sata

From: Arnd Bergmann <hidden>
Date: 2014-01-04 21:39:50
Also in: linux-arm-kernel, linux-ide

On Saturday 04 January 2014 10:14:36 Hans de Goede wrote:
quoted hunk
diff --git a/Documentation/devicetree/bindings/ata/ahci-sunxi.txt b/Documentation/devicetree/bindings/ata/ahci-sunxi.txt
new file mode 100644
index 0000000..0792fa5
--- /dev/null
+++ b/Documentation/devicetree/bindings/ata/ahci-sunxi.txt
@@ -0,0 +1,24 @@
+Allwinner SUNXI AHCI SATA Controller
+
+SATA nodes are defined to describe on-chip Serial ATA controllers.
+Each SATA controller should have its own node.
+
+Required properties:
+- compatible	: compatible list, contains "allwinner,sun4i-a10-ahci"
+- reg		: <registers mapping>
+- interrupts	: <interrupt mapping for AHCI IRQ>
+- clocks	: clocks for ACHI
+- clock-names	: clock names for AHCI
The binding needs to specify the required names for the clocks.
+Optional properties:
+- pwr-supply	: regulator to control the power supply GPIO
+
+Example:
+	ahci@01c18000 {
+		compatible = "allwinner,sun4i-a10-ahci";
+		reg = <0x01c18000 0x1000>;
+		interrupts = <0 56 1>;
+		clocks = <&ahb_gates 25>, <&pll6 0>;
+		clock-names = "ahb_sata", "pll6_sata";
"pll6_sata" doesn't sound particularly generic. The name should
reflect what the clock is used for, not what drives it.

Also, please send the binding as a separate patch with Cc to
the devicetree-discuss mailing list.
+
+static int sunxi_ahci_phy_init(struct device *dev, void __iomem *reg_base)
+{
+	u32 reg_val;
+	int timeout;
+
+	/* This magic is from the original code */
+	writel(0, reg_base + AHCI_RWCR);
+	mdelay(5);
This function should probably be in a separate phy driver. I would
very much hope that we can minimize the required code in an AHCI
driver and move code from this new file into the ahci-platform
driver. The clock, regulator and phy setup can all be optional
properties of the generic driver, and then there shouldn't
be much left that is sunxi specific.
+static int sunxi_ahci_susp(struct device *dev)
+{
+	struct ata_host *host = dev_get_drvdata(dev);
+	struct ahci_host_priv *hpriv = host->private_data;
+	struct sunxi_ahci *ahci = hpriv->plat_data;
+	int ret;
+
+	/*
+	 * AHCI spec rev1.1 section 8.3.3:
+	 * Software must disable interrupts prior to requesting a
+	 * transition of the HBA to D3 state.
+	 */
+	sunxi_clrbits(hpriv->mmio + HOST_CTL, HOST_IRQ_EN);
+
+	ret = ata_host_suspend(host, PMSG_SUSPEND);
+	if (ret)
+		return ret;
+
+	sunxi_ahci_disable_clks(ahci);
+
+	return 0;
+}
The only thing in here that seems sunxi-specific is the irq disabling
part. Can't you do this instead by calling disable_irq() and make
the function completely generic?

	Arnd
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