Fwd: [PATCH 1/2] clk: keystone: add support for post divider register for main pll

[Murali Karicheri]

Santosh,

Can you send a pull request to clock subsystem to be picked up for v4.2 
and apply the dts part to keystone for the same merge window? or are we 
too late for this?

Murali

-------- Forwarded Message --------
Subject: [PATCH 1/2] clk: keystone: add support for post divider 
register for main pll
Date: Fri, 29 May 2015 12:04:12 -0400
From: Murali Karicheri <m-karicheri2 at ti.com>
To: robh+dt at kernel.org, pawel.moll at arm.com, mark.rutland at arm.com, 
ijc+devicetree at hellion.org.uk, galak at codeaurora.org, 
ssantosh at kernel.org, mturquette at linaro.org, sboyd at codeaurora.org, 
devicetree at vger.kernel.org, linux-kernel at vger.kernel.org, 
linux-clk at vger.kernel.org, linux at arm.linux.org.uk, 
linux-arm-kernel at lists.infradead.org
CC: Murali Karicheri <m-karicheri2 at ti.com>

Main PLL controller has post divider bits in a separate register in
pll controller. Use the value from this register instead of fixed
divider when available.

Signed-off-by: Murali Karicheri <m-karicheri2 at ti.com>
---
  .../devicetree/bindings/clock/keystone-pll.txt       |  8 ++++----
  drivers/clk/keystone/pll.c                           | 20 
++++++++++++++++++--
  2 files changed, 22 insertions(+), 6 deletions(-)

diff --git a/Documentation/devicetree/bindings/clock/keystone-pll.txt 
b/Documentation/devicetree/bindings/clock/keystone-pll.txt
index 225990f..47570d2 100644
--- a/Documentation/devicetree/bindings/clock/keystone-pll.txt
+++ b/Documentation/devicetree/bindings/clock/keystone-pll.txt
@@ -15,8 +15,8 @@ Required properties:
  - compatible : shall be "ti,keystone,main-pll-clock" or 
"ti,keystone,pll-clock"
  - clocks : parent clock phandle
  - reg - pll control0 and pll multipler registers
-- reg-names : control and multiplier. The multiplier is applicable only for
-		main pll clock
+- reg-names : control, multiplier and post-divider. The multiplier and
+		post-divider registers are applicable only for main pll clock
  - fixed-postdiv : fixed post divider value. If absent, use clkod 
register bits
  		for postdiv

@@ -25,8 +25,8 @@ Example:
  		#clock-cells = <0>;
  		compatible = "ti,keystone,main-pll-clock";
  		clocks = <&refclksys>;
-		reg = <0x02620350 4>, <0x02310110 4>;
-		reg-names = "control", "multiplier";
+		reg = <0x02620350 4>, <0x02310110 4>, <0x02310108 4>;
+		reg-names = "control", "multiplier", "post-divider";
  		fixed-postdiv = <2>;
  	};

diff --git a/drivers/clk/keystone/pll.c b/drivers/clk/keystone/pll.c
index 0dd8a4b..4a375ea 100644
--- a/drivers/clk/keystone/pll.c
+++ b/drivers/clk/keystone/pll.c
@@ -37,7 +37,8 @@
   *	Main PLL or any other PLLs in the device such as ARM PLL, DDR PLL
   *	or PA PLL available on keystone2. These PLLs are controlled by
   *	this register. Main PLL is controlled by a PLL controller.
- * @pllm: PLL register map address
+ * @pllm: PLL register map address for multiplier bits
+ * @pllod: PLL register map address for post divider bits
   * @pll_ctl0: PLL controller map address
   * @pllm_lower_mask: multiplier lower mask
   * @pllm_upper_mask: multiplier upper mask
@@ -53,6 +54,7 @@ struct clk_pll_data {
  	u32 phy_pllm;
  	u32 phy_pll_ctl0;
  	void __iomem *pllm;
+	void __iomem *pllod;
  	void __iomem *pll_ctl0;
  	u32 pllm_lower_mask;
  	u32 pllm_upper_mask;
@@ -102,7 +104,11 @@ static unsigned long clk_pllclk_recalc(struct 
clk_hw *hw,
  		/* read post divider from od bits*/
  		postdiv = ((val & pll_data->clkod_mask) >>
  				 pll_data->clkod_shift) + 1;
-	else
+	else if (pll_data->pllod) {
+		postdiv = readl(pll_data->pllod);
+		postdiv = ((postdiv & pll_data->clkod_mask) >>
+				pll_data->clkod_shift) + 1;
+	} else
  		postdiv = pll_data->postdiv;

  	rate /= (prediv + 1);
@@ -172,12 +178,21 @@ static void __init _of_pll_clk_init(struct 
device_node *node, bool pllctrl)
  		/* assume the PLL has output divider register bits */
  		pll_data->clkod_mask = CLKOD_MASK;
  		pll_data->clkod_shift = CLKOD_SHIFT;
+
+		/*
+		 * Check if there is an post-divider register. If not
+		 * assume od bits are part of control register.
+		 */
+		i = of_property_match_string(node, "reg-names",
+					     "post-divider");
+		pll_data->pllod = of_iomap(node, i);
  	}

  	i = of_property_match_string(node, "reg-names", "control");
  	pll_data->pll_ctl0 = of_iomap(node, i);
  	if (!pll_data->pll_ctl0) {
  		pr_err("%s: ioremap failed\n", __func__);
+		iounmap(pll_data->pllod);
  		goto out;
  	}

@@ -193,6 +208,7 @@ static void __init _of_pll_clk_init(struct 
device_node *node, bool pllctrl)
  		pll_data->pllm = of_iomap(node, i);
  		if (!pll_data->pllm) {
  			iounmap(pll_data->pll_ctl0);
+			iounmap(pll_data->pllod);
  			goto out;
  		}
  	}
-- 
1.9.1




-- 
Murali Karicheri
Linux Kernel, Keystone