Thread (15 messages) 15 messages, 3 authors, 2018-09-04

Re: [PATCH v6 4/5] clk: imx: add imx composite clock

From: Sascha Hauer <s.hauer@pengutronix.de>
Date: 2018-08-24 07:43:59
Also in: linux-clk, lkml

On Wed, Aug 22, 2018 at 04:48:22PM +0300, Abel Vesa wrote:
quoted hunk ↗ jump to hunk
Since a lot of clocks on imx8 are formed by a mux, gate, predivider and
divider, the idea here is to combine all of those into one composite clock,
but we need to deal with both predivider and divider at the same time and
therefore we add the imx_clk_composite_divider_ops and register the composite
clock with those.

Signed-off-by: Abel Vesa <redacted>
Suggested-by: Sascha Hauer <s.hauer@pengutronix.de>
---
 drivers/clk/imx/Makefile        |   1 +
 drivers/clk/imx/clk-composite.c | 157 ++++++++++++++++++++++++++++++++++++++++
 drivers/clk/imx/clk.h           |   9 +++
 3 files changed, 167 insertions(+)
 create mode 100644 drivers/clk/imx/clk-composite.c
diff --git a/drivers/clk/imx/Makefile b/drivers/clk/imx/Makefile
index b87513c..4fabb0a 100644
--- a/drivers/clk/imx/Makefile
+++ b/drivers/clk/imx/Makefile
@@ -3,6 +3,7 @@
 obj-y += \
 	clk.o \
 	clk-busy.o \
+	clk-composite.o \
 	clk-cpu.o \
 	clk-fixup-div.o \
 	clk-fixup-mux.o \
diff --git a/drivers/clk/imx/clk-composite.c b/drivers/clk/imx/clk-composite.c
new file mode 100644
index 0000000..a5c0080
--- /dev/null
+++ b/drivers/clk/imx/clk-composite.c
@@ -0,0 +1,157 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright 2018 NXP
+ */
+
+#include <linux/errno.h>
+#include <linux/slab.h>
+#include <linux/clk-provider.h>
+#include <linux/clk.h>
+
+#include "clk.h"
+
+#define PCG_PREDIV_SHIFT	16
+#define PCG_PREDIV_WIDTH	3
+
+#define PCG_DIV_SHIFT		0
+#define PCG_DIV_WIDTH		6
+
+#define PCG_PCS_SHIFT		24
+#define PCG_PCS_MASK		0x7
+
+#define PCG_CGC_SHIFT		28
+
+static unsigned long imx_clk_composite_divider_recalc_rate(struct clk_hw *hw,
+						unsigned long parent_rate)
+{
+	struct clk_divider *divider = to_clk_divider(hw);
+	unsigned long prediv_rate;
+	unsigned int prediv_value;
+	unsigned int div_value;
+
+	prediv_value = clk_readl(divider->reg) >> divider->shift;
+	prediv_value &= clk_div_mask(divider->width);
+
+	prediv_rate = divider_recalc_rate(hw, parent_rate, prediv_value,
+						divider->table, divider->flags,
+						divider->width);
+
+	div_value = clk_readl(divider->reg) >> PCG_DIV_SHIFT;
+	div_value &= clk_div_mask(PCG_DIV_WIDTH);
+
+	return divider_recalc_rate(hw, prediv_rate, div_value, divider->table,
+				   divider->flags, PCG_DIV_WIDTH);
This is no table based divider, so divider->table is NULL, right? It's
clearer to just write NULL here instead.

Otherwise this looks good for me now.

Sascha


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