ARM: Orion: CESA: Add support for clk

Some orion platforms support gating of the clock. If the clock exists
enable/disbale it as appropriate.
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Tested-by: Jamie Lentin <jm@lentin.co.uk>
Signed-off-by: Mike Turquette <mturquette@linaro.org>

arch/arm/mach-kirkwood/common.c

@@ -87,6 +87,7 @@ static struct clk __init *kirkwood_register_gate(const char *name, u8 bit_idx)
 void __init kirkwood_clk_init(void)
 {
 	struct clk *runit, *ge0, *ge1, *sata0, *sata1, *usb0, *sdio;
+	struct clk *crypto;
 
 	tclk = clk_register_fixed_rate(NULL, "tclk", NULL,
 				       CLK_IS_ROOT, kirkwood_tclk);
@@ -98,7 +99,7 @@ void __init kirkwood_clk_init(void)
 	sata1 = kirkwood_register_gate("sata1",  CGC_BIT_SATA1);
 	usb0 = kirkwood_register_gate("usb0",   CGC_BIT_USB0);
 	sdio = kirkwood_register_gate("sdio",   CGC_BIT_SDIO);
-	kirkwood_register_gate("crypto", CGC_BIT_CRYPTO);
+	crypto = kirkwood_register_gate("crypto", CGC_BIT_CRYPTO);
 	kirkwood_register_gate("xor0",   CGC_BIT_XOR0);
 	kirkwood_register_gate("xor1",   CGC_BIT_XOR1);
 	kirkwood_register_gate("pex0",   CGC_BIT_PEX0);
@@ -118,6 +119,7 @@ void __init kirkwood_clk_init(void)
 	orion_clkdev_add(NULL, "orion-ehci.0", usb0);
 	orion_clkdev_add(NULL, "orion_nand", runit);
 	orion_clkdev_add(NULL, "mvsdio", sdio);
+	orion_clkdev_add(NULL, "mv_crypto", crypto);
 }
 
 /*****************************************************************************

drivers/crypto/mv_cesa.c

@@ -16,6 +16,7 @@
 #include <linux/scatterlist.h>
 #include <linux/slab.h>
 #include <linux/module.h>
+#include <linux/clk.h>
 #include <crypto/internal/hash.h>
 #include <crypto/sha.h>
 
@@ -79,6 +80,7 @@ struct crypto_priv {
 	void __iomem *reg;
 	void __iomem *sram;
 	int irq;
+	struct clk *clk;
 	struct task_struct *queue_th;
 
 	/* the lock protects queue and eng_st */
@@ -1053,6 +1055,12 @@ static int mv_probe(struct platform_device *pdev)
 	if (ret)
 		goto err_thread;
 
+	/* Not all platforms can gate the clock, so it is not
+	   an error if the clock does not exists. */
+	cp->clk = clk_get(&pdev->dev, NULL);
+	if (!IS_ERR(cp->clk))
+		clk_prepare_enable(cp->clk);
+
 	writel(SEC_INT_ACCEL0_DONE, cpg->reg + SEC_ACCEL_INT_MASK);
 	writel(SEC_CFG_STOP_DIG_ERR, cpg->reg + SEC_ACCEL_CFG);
 	writel(SRAM_CONFIG, cpg->reg + SEC_ACCEL_DESC_P0);
@@ -1118,6 +1126,12 @@ static int mv_remove(struct platform_device *pdev)
 	memset(cp->sram, 0, cp->sram_size);
 	iounmap(cp->sram);
 	iounmap(cp->reg);
+
+	if (!IS_ERR(cp->clk)) {
+		clk_disable_unprepare(cp->clk);
+		clk_put(cp->clk);
+	}
+
 	kfree(cp);
 	cpg = NULL;
 	return 0;