mtd: gpmi: change the code for clocks

The gpmi nand driver may needs several clocks(MX6Q needs five clocks).

In the old clock framework, all these clocks are chained together,
all you need is to manipulate the first clock.

But the kernel uses the common clk framework now, which forces us to
get the clocks one by one. When we use them, we have to enable them
one by one too.

Signed-off-by: Huang Shijie <shijie8@gmail.com>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

1 files changed, 73 insertions, 9 deletions

diff --git a/drivers/mtd/nand/gpmi-nand/gpmi-nand.c b/drivers/mtd/nand/gpmi-nand/gpmi-nand.c
index 9da9ee88a824..8c0d2f0a526f 100644
--- a/drivers/mtd/nand/gpmi-nand/gpmi-nand.c
+++ b/drivers/mtd/nand/gpmi-nand/gpmi-nand.c
@@ -465,9 +465,78 @@ acquire_err:
 	return -EINVAL;
 }
 
+static void gpmi_put_clks(struct gpmi_nand_data *this)
+{
+	struct resources *r = &this->resources;
+	struct clk *clk;
+	int i;
+
+	for (i = 0; i < GPMI_CLK_MAX; i++) {
+		clk = r->clock[i];
+		if (clk) {
+			clk_put(clk);
+			r->clock[i] = NULL;
+		}
+	}
+}
+
+static char *extra_clks_for_mx6q[GPMI_CLK_MAX] = {
+	"gpmi_apb", "gpmi_bch", "gpmi_bch_apb", "per1_bch",
+};
+
+static int __devinit gpmi_get_clks(struct gpmi_nand_data *this)
+{
+	struct resources *r = &this->resources;
+	char **extra_clks = NULL;
+	struct clk *clk;
+	int i;
+
+	/* The main clock is stored in the first. */
+	r->clock[0] = clk_get(this->dev, "gpmi_io");
+	if (IS_ERR(r->clock[0]))
+		goto err_clock;
+
+	/* Get extra clocks */
+	if (GPMI_IS_MX6Q(this))
+		extra_clks = extra_clks_for_mx6q;
+	if (!extra_clks)
+		return 0;
+
+	for (i = 1; i < GPMI_CLK_MAX; i++) {
+		if (extra_clks[i - 1] == NULL)
+			break;
+
+		clk = clk_get(this->dev, extra_clks[i - 1]);
+		if (IS_ERR(clk))
+			goto err_clock;
+
+		r->clock[i] = clk;
+	}
+
+	if (GPMI_IS_MX6Q(this)) {
+		/*
+		 * Set the default values for the clocks in mx6q:
+		 *    The main clock(enfc) : 22MHz
+		 *    The others           : 44.5MHz
+		 *
+		 * These are just the default values. If you want to use
+		 * the ONFI nand which is in the Synchronous Mode, you should
+		 * change the clocks's frequencies as you need.
+		 */
+		clk_set_rate(r->clock[0], 22000000);
+		for (i = 1; i < GPMI_CLK_MAX && r->clock[i]; i++)
+			clk_set_rate(r->clock[i], 44500000);
+	}
+	return 0;
+
+err_clock:
+	dev_dbg(this->dev, "failed in finding the clocks.\n");
+	gpmi_put_clks(this);
+	return -ENOMEM;
+}
+
 static int __devinit acquire_resources(struct gpmi_nand_data *this)
 {
-	struct resources *res = &this->resources;
 	struct pinctrl *pinctrl;
 	int ret;
 
@@ -493,12 +562,9 @@ static int __devinit acquire_resources(struct gpmi_nand_data *this)
 		goto exit_pin;
 	}
 
-	res->clock = clk_get(&this->pdev->dev, NULL);
-	if (IS_ERR(res->clock)) {
-		pr_err("can not get the clock\n");
-		ret = -ENOENT;
+	ret = gpmi_get_clks(this);
+	if (ret)
 		goto exit_clock;
-	}
 	return 0;
 
 exit_clock:
@@ -513,9 +579,7 @@ exit_regs:
 
 static void release_resources(struct gpmi_nand_data *this)
 {
-	struct resources *r = &this->resources;
-
-	clk_put(r->clock);
+	gpmi_put_clks(this);
 	release_register_block(this);
 	release_bch_irq(this);
 	release_dma_channels(this);