Revert "Input: olpc_apsp - enable the SP clock"

Turns out this is not such a great idea. Once the SP clock is disabled,
it's not sufficient to just enable in order to bring the SP core back up.

It seems that the kernel has no business managing this clock. Just let
the firmware keep it enabled.

This reverts commit ed22cee.

Link: https://lore.kernel.org/lkml/154783267051.169631.3197836544646625747@swboyd.mtv.corp.google.com/
Signed-off-by: Lubomir Rintel <lkundrak@v3.sk>
Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>

Documentation/devicetree/bindings/serio/olpc,ap-sp.txt

@@ -4,14 +4,10 @@ Required properties:
 - compatible : "olpc,ap-sp"
 - reg : base address and length of SoC's WTM registers
 - interrupts : SP-AP interrupt
-- clocks : phandle + clock-specifier for the clock that drives the WTM
-- clock-names:  should be "sp"
 
 Example:
 	ap-sp@d4290000 {
 		compatible = "olpc,ap-sp";
 		reg = <0xd4290000 0x1000>;
 		interrupts = <40>;
-		clocks = <&soc_clocks MMP2_CLK_SP>;
-		clock-names = "sp";
 	}

drivers/input/serio/olpc_apsp.c

@@ -23,7 +23,6 @@
 #include <linux/of.h>
 #include <linux/slab.h>
 #include <linux/delay.h>
-#include <linux/clk.h>
 
 /*
  * The OLPC XO-1.75 and XO-4 laptops do not have a hardware PS/2 controller.
@@ -75,7 +74,6 @@ struct olpc_apsp {
 	struct serio *kbio;
 	struct serio *padio;
 	void __iomem *base;
-	struct clk *clk;
 	int open_count;
 	int irq;
 };
@@ -148,17 +146,11 @@ static int olpc_apsp_open(struct serio *port)
 	struct olpc_apsp *priv = port->port_data;
 	unsigned int tmp;
 	unsigned long l;
-	int error;
 
 	if (priv->open_count++ == 0) {
-		error = clk_prepare_enable(priv->clk);
-		if (error)
-			return error;
-
 		l = readl(priv->base + COMMAND_FIFO_STATUS);
 		if (!(l & CMD_STS_MASK)) {
 			dev_err(priv->dev, "SP cannot accept commands.\n");
-			clk_disable_unprepare(priv->clk);
 			return -EIO;
 		}
 
@@ -179,8 +171,6 @@ static void olpc_apsp_close(struct serio *port)
 		/* Disable interrupt 0 */
 		tmp = readl(priv->base + PJ_INTERRUPT_MASK);
 		writel(tmp | INT_0, priv->base + PJ_INTERRUPT_MASK);
-
-		clk_disable_unprepare(priv->clk);
 	}
 }
 
@@ -206,10 +196,6 @@ static int olpc_apsp_probe(struct platform_device *pdev)
 	if (priv->irq < 0)
 		return priv->irq;
 
-	priv->clk = devm_clk_get(&pdev->dev, "sp");
-	if (IS_ERR(priv->clk))
-		return PTR_ERR(priv->clk);
-
 	/* KEYBOARD */
 	kb_serio = kzalloc(sizeof(struct serio), GFP_KERNEL);
 	if (!kb_serio)