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* [PATCH linux-next (v2) 1/2] clk: Add brcm,bcm6345-gate-clk device tree binding
@ 2015-12-10 21:49 Simon Arlott
  2015-12-10 21:50 ` [PATCH linux-next (v2) 2/2] clk: bcm6345: Add BCM6345 gated clock support Simon Arlott
                   ` (2 more replies)
  0 siblings, 3 replies; 5+ messages in thread
From: Simon Arlott @ 2015-12-10 21:49 UTC (permalink / raw)
  To: Michael Turquette, Stephen Boyd, Kevin Cernekee,
	Florian Fainelli, devicetree
  Cc: Linux Kernel Mailing List, linux-clk, linux-mips, Rob Herring,
	Pawel Moll, Mark Rutland, Ian Campbell, Kumar Gala, Jonas Gorski

Add device tree binding for the BCM6345's gated clocks.

The BCM6345 contains clocks gated with a register. Clocks are indexed
by bits in the register and are active high. Most MIPS-based BCM63xx
SoCs have a clock gating set of registers, but some have clock gate bits
interleaved with other status bits and configurable clocks in the same
register.

Signed-off-by: Simon Arlott <simon@fire.lp0.eu>
---
v2: Added clock-indices, clock-output-names (from clock-bindings.txt),
    these are required properties.

v1: Renamed from BCM63xx to BCM6345.

 .../bindings/clock/brcm,bcm6345-gate-clk.txt       | 62 ++++++++++++++++++++++
 1 file changed, 62 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/clock/brcm,bcm6345-gate-clk.txt

diff --git a/Documentation/devicetree/bindings/clock/brcm,bcm6345-gate-clk.txt b/Documentation/devicetree/bindings/clock/brcm,bcm6345-gate-clk.txt
new file mode 100644
index 0000000..a6e264c
--- /dev/null
+++ b/Documentation/devicetree/bindings/clock/brcm,bcm6345-gate-clk.txt
@@ -0,0 +1,62 @@
+Broadcom BCM6345 clocks
+
+This binding uses the common clock binding:
+	Documentation/devicetree/bindings/clock/clock-bindings.txt
+
+The BCM6345 contains clocks gated with a register. Clocks are indexed
+by bits in the register and are active high. Most MIPS-based BCM63xx
+SoCs have a clock gating set of registers, but some have clock gate bits
+interleaved with other status bits and configurable clocks in the same
+register.
+
+Required properties:
+- compatible:         Should be "brcm,bcm<soc>-gate-clk", "brcm,bcm6345-gate-clk"
+- #clock-cells:       Should be <1>.
+- regmap:             The register map phandle
+- offset:             Offset in the register map for the clock register (in bytes)
+- clocks:             The external oscillator clock phandle
+- clock-indices:      The bits in the register used for gated clocks.
+- clock-output-names: Should be a list of strings of clock output signal
+                      names indexed by the clock indices.
+
+Example:
+
+periph_clk: periph_clk {
+	compatible = "brcm,bcm63168-gate-clk", "brcm,bcm6345-gate-clk";
+	regmap = <&periph_cntl>;
+	offset = <0x4>;
+
+	#clock-cells = <1>;
+	clock-indices =
+		<1>,          <2>,        <3>,       <4>,     <5>,
+		<6>,          <7>,        <8>,       <9>,     <10>,
+		<11>,         <12>,       <13>,      <14>,    <15>,
+		<16>,         <17>,       <18>,      <19>,    <20>,
+		<27>,         <31>;
+	clock-output-names =
+		"vdsl_qproc", "vdsl_afe", "vdsl",    "mips",  "wlan_ocp",
+		"dect",       "fap0",     "fap1",    "sar",   "robosw",
+		"pcm",        "usbd",     "usbh",    "ipsec", "spi",
+		"hsspi",      "pcie",     "phymips", "gmac",  "nand",
+		"tbus",       "robosw250";
+};
+
+timer_clk: timer_clk {
+	compatible = "brcm,bcm63168-gate-clk", "brcm,bcm6345-gate-clk";
+	regmap = <&timer_cntl>;
+	offset = <0x4>;
+
+	#clock-cells = <1>;
+	clock-indices = <17>, <18>;
+	clock-output-names = "uto_extin", "usb_ref";
+};
+
+ehci0: usb@10002500 {
+	compatible = "brcm,bcm63168-ehci", "brcm,bcm6345-ehci", "generic-ehci";
+	reg = <0x10002500 0x100>;
+	big-endian;
+	interrupt-parent = <&periph_intc>;
+	interrupts = <10>;
+	clocks = <&periph_clk 13>, <&timer_clk 18>;
+	phys = <&usbh>;
+};
-- 
2.1.4

-- 
Simon Arlott

^ permalink raw reply related	[flat|nested] 5+ messages in thread

* [PATCH linux-next (v2) 2/2] clk: bcm6345: Add BCM6345 gated clock support
  2015-12-10 21:49 [PATCH linux-next (v2) 1/2] clk: Add brcm,bcm6345-gate-clk device tree binding Simon Arlott
@ 2015-12-10 21:50 ` Simon Arlott
  2016-01-01 23:40   ` Michael Turquette
  2015-12-11  3:48 ` [PATCH linux-next (v2) 1/2] clk: Add brcm,bcm6345-gate-clk device tree binding Rob Herring
  2016-01-01  7:16 ` [PATCH linux-next (v2) 1/2] clk: Add brcm, bcm6345-gate-clk " Michael Turquette
  2 siblings, 1 reply; 5+ messages in thread
From: Simon Arlott @ 2015-12-10 21:50 UTC (permalink / raw)
  To: Michael Turquette, Stephen Boyd, Kevin Cernekee,
	Florian Fainelli, devicetree
  Cc: Linux Kernel Mailing List, linux-clk, linux-mips, Rob Herring,
	Pawel Moll, Mark Rutland, Ian Campbell, Kumar Gala, Jonas Gorski

The BCM6345 contains clocks gated with a register. Clocks are indexed
by bits in the register and are active high. Most MIPS-based BCM63xx
SoCs have a clock gating set of registers, but some have clock gate bits
interleaved with other status bits and configurable clocks in the same
register.

Enabled by default for BMIPS_GENERIC.

Signed-off-by: Simon Arlott <simon@fire.lp0.eu>
---
v2: Resend, no changes.

v1: Renamed from BCM63xx to BCM6345.

 MAINTAINERS                   |   1 +
 drivers/clk/bcm/Kconfig       |   9 ++
 drivers/clk/bcm/Makefile      |   1 +
 drivers/clk/bcm/clk-bcm6345.c | 191 ++++++++++++++++++++++++++++++++++++++++++
 4 files changed, 202 insertions(+)
 create mode 100644 drivers/clk/bcm/clk-bcm6345.c

diff --git a/MAINTAINERS b/MAINTAINERS
index 5ac17b0..9b54ddc 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -2389,6 +2389,7 @@ F:	arch/mips/bmips/*
 F:	arch/mips/include/asm/mach-bmips/*
 F:	arch/mips/kernel/*bmips*
 F:	arch/mips/boot/dts/brcm/bcm*.dts*
+F:	drivers/clk/bcm/clk-bcm6345*
 F:	drivers/irqchip/irq-bcm63*
 F:	drivers/irqchip/irq-bcm7*
 F:	drivers/irqchip/irq-brcmstb*
diff --git a/drivers/clk/bcm/Kconfig b/drivers/clk/bcm/Kconfig
index f287845..043353a 100644
--- a/drivers/clk/bcm/Kconfig
+++ b/drivers/clk/bcm/Kconfig
@@ -8,6 +8,15 @@ config CLK_BCM_63XX
 	  Enable common clock framework support for Broadcom BCM63xx DSL SoCs
 	  based on the ARM architecture
 
+config CLK_BCM_6345
+	bool "Broadcom BCM6345 clock support"
+	depends on BMIPS_GENERIC || COMPILE_TEST
+	depends on COMMON_CLK
+	default BMIPS_GENERIC
+	help
+	  Enable common clock framework support for Broadcom BCM6345 DSL SoCs
+	  based on the MIPS architecture
+
 config CLK_BCM_KONA
 	bool "Broadcom Kona CCU clock support"
 	depends on ARCH_BCM_MOBILE || COMPILE_TEST
diff --git a/drivers/clk/bcm/Makefile b/drivers/clk/bcm/Makefile
index 247c267..e2bac43 100644
--- a/drivers/clk/bcm/Makefile
+++ b/drivers/clk/bcm/Makefile
@@ -1,4 +1,5 @@
 obj-$(CONFIG_CLK_BCM_63XX)	+= clk-bcm63xx.o
+obj-$(CONFIG_CLK_BCM_6345)	+= clk-bcm6345.o
 obj-$(CONFIG_CLK_BCM_KONA)	+= clk-kona.o
 obj-$(CONFIG_CLK_BCM_KONA)	+= clk-kona-setup.o
 obj-$(CONFIG_CLK_BCM_KONA)	+= clk-bcm281xx.o
diff --git a/drivers/clk/bcm/clk-bcm6345.c b/drivers/clk/bcm/clk-bcm6345.c
new file mode 100644
index 0000000..88a1e7e
--- /dev/null
+++ b/drivers/clk/bcm/clk-bcm6345.c
@@ -0,0 +1,191 @@
+/*
+ * Copyright 2015 Simon Arlott
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation version 2.
+ *
+ * This program is distributed "as is" WITHOUT ANY WARRANTY of any
+ * kind, whether express or implied; without even the implied warranty
+ * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * Derived from clk-gate.c:
+ * Copyright (C) 2010-2011 Canonical Ltd <jeremy.kerr@canonical.com>
+ * Copyright (C) 2011-2012 Mike Turquette, Linaro Ltd <mturquette@linaro.org>
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/clk-provider.h>
+#include <linux/err.h>
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/mfd/syscon.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/regmap.h>
+#include <linux/slab.h>
+#include <linux/string.h>
+
+/**
+ * DOC: Basic clock which uses a bit in a regmap to gate and ungate the output
+ *
+ * Traits of this clock:
+ * prepare - clk_(un)prepare only ensures parent is (un)prepared
+ * enable - clk_enable and clk_disable are functional & control gating
+ * rate - inherits rate from parent.  No clk_set_rate support
+ * parent - fixed parent.  No clk_set_parent support
+ */
+
+struct clk_bcm6345 {
+	struct clk_hw hw;
+	struct regmap *map;
+	u32 offset;
+	u32 mask;
+};
+
+#define to_clk_bcm6345(_hw) container_of(_hw, struct clk_bcm6345, hw)
+
+static int clk_bcm6345_enable(struct clk_hw *hw)
+{
+	struct clk_bcm6345 *gate = to_clk_bcm6345(hw);
+
+	return regmap_write_bits(gate->map, gate->offset,
+					gate->mask, gate->mask);
+}
+
+static void clk_bcm6345_disable(struct clk_hw *hw)
+{
+	struct clk_bcm6345 *gate = to_clk_bcm6345(hw);
+
+	regmap_write_bits(gate->map, gate->offset,
+					gate->mask, 0);
+}
+
+static int clk_bcm6345_is_enabled(struct clk_hw *hw)
+{
+	struct clk_bcm6345 *gate = to_clk_bcm6345(hw);
+	unsigned int val;
+	int ret;
+
+	ret = regmap_read(gate->map, gate->offset, &val);
+	if (ret)
+		return ret;
+
+	val &= gate->mask;
+
+	return val ? 1 : 0;
+}
+
+const struct clk_ops clk_bcm6345_ops = {
+	.enable = clk_bcm6345_enable,
+	.disable = clk_bcm6345_disable,
+	.is_enabled = clk_bcm6345_is_enabled,
+};
+
+static struct clk * __init of_bcm6345_clk_register(const char *parent_name,
+	const char *clk_name, struct regmap *map, u32 offset, u32 mask)
+{
+	struct clk_bcm6345 *gate;
+	struct clk_init_data init;
+	struct clk *ret;
+
+	gate = kzalloc(sizeof(*gate), GFP_KERNEL);
+	if (!gate)
+		return ERR_PTR(-ENOMEM);
+
+	init.name = clk_name;
+	init.ops = &clk_bcm6345_ops;
+	init.flags = CLK_IS_BASIC;
+	init.parent_names = (parent_name ? &parent_name : NULL);
+	init.num_parents = (parent_name ? 1 : 0);
+	gate->hw.init = &init;
+	gate->map = map;
+	gate->offset = offset;
+	gate->mask = mask;
+
+	ret = clk_register(NULL, &gate->hw);
+	if (IS_ERR(ret))
+		kfree(gate);
+
+	return ret;
+}
+
+static void __init of_bcm6345_clk_setup(struct device_node *node)
+{
+	struct clk_onecell_data *clk_data;
+	const char *parent_name = NULL;
+	struct regmap *map;
+	u32 offset;
+	unsigned int clocks = 0;
+	int i;
+
+	clk_data = kzalloc(sizeof(*clk_data), GFP_KERNEL);
+	if (!clk_data)
+		return;
+
+	clk_data->clk_num = 32;
+	clk_data->clks = kmalloc_array(clk_data->clk_num,
+		sizeof(*clk_data->clks), GFP_KERNEL);
+
+	for (i = 0; i < clk_data->clk_num; i++)
+		clk_data->clks[i] = ERR_PTR(-ENODEV);
+
+	if (of_clk_get_parent_count(node) > 0)
+		parent_name = of_clk_get_parent_name(node, 0);
+
+	map = syscon_regmap_lookup_by_phandle(node, "regmap");
+	if (IS_ERR(map)) {
+		pr_err("%s: regmap lookup error %ld\n",
+			node->full_name, PTR_ERR(map));
+		goto out;
+	}
+
+	if (of_property_read_u32(node, "offset", &offset)) {
+		pr_err("%s: offset not specified\n", node->full_name);
+		goto out;
+	}
+
+	/* clks[] is sparse, indexed by bit, maximum clocks checked using i */
+	for (i = 0; i < clk_data->clk_num; i++) {
+		u32 bit;
+		const char *clk_name;
+
+		if (of_property_read_u32_index(node, "clock-indices",
+				i, &bit))
+			goto out;
+
+		if (of_property_read_string_index(node, "clock-output-names",
+				i, &clk_name))
+			goto out;
+
+		if (bit >= clk_data->clk_num) {
+			pr_err("%s: clock bit %u out of range\n",
+				node->full_name, bit);
+			continue;
+		}
+
+		if (!IS_ERR(clk_data->clks[bit])) {
+			pr_err("%s: clock bit %u already exists\n",
+				node->full_name, bit);
+			continue;
+		}
+
+		clk_data->clks[bit] = of_bcm6345_clk_register(parent_name,
+					clk_name, map, offset, BIT(bit));
+		if (!IS_ERR(clk_data->clks[bit]))
+			clocks++;
+	}
+
+out:
+	if (clocks) {
+		of_clk_add_provider(node, of_clk_src_onecell_get, clk_data);
+		pr_info("%s: registered %u clocks\n", node->name, clocks);
+	} else {
+		kfree(clk_data->clks);
+		kfree(clk_data);
+	}
+}
+
+CLK_OF_DECLARE(bcm6345_clk, "brcm,bcm6345-gate-clk", of_bcm6345_clk_setup);
-- 
2.1.4

-- 
Simon Arlott

^ permalink raw reply related	[flat|nested] 5+ messages in thread

* Re: [PATCH linux-next (v2) 1/2] clk: Add brcm,bcm6345-gate-clk device tree binding
  2015-12-10 21:49 [PATCH linux-next (v2) 1/2] clk: Add brcm,bcm6345-gate-clk device tree binding Simon Arlott
  2015-12-10 21:50 ` [PATCH linux-next (v2) 2/2] clk: bcm6345: Add BCM6345 gated clock support Simon Arlott
@ 2015-12-11  3:48 ` Rob Herring
  2016-01-01  7:16 ` [PATCH linux-next (v2) 1/2] clk: Add brcm, bcm6345-gate-clk " Michael Turquette
  2 siblings, 0 replies; 5+ messages in thread
From: Rob Herring @ 2015-12-11  3:48 UTC (permalink / raw)
  To: Simon Arlott
  Cc: Michael Turquette, Stephen Boyd, Kevin Cernekee,
	Florian Fainelli, devicetree, Linux Kernel Mailing List,
	linux-clk, linux-mips, Pawel Moll, Mark Rutland, Ian Campbell,
	Kumar Gala, Jonas Gorski

On Thu, Dec 10, 2015 at 09:49:21PM +0000, Simon Arlott wrote:
> Add device tree binding for the BCM6345's gated clocks.
> 
> The BCM6345 contains clocks gated with a register. Clocks are indexed
> by bits in the register and are active high. Most MIPS-based BCM63xx
> SoCs have a clock gating set of registers, but some have clock gate bits
> interleaved with other status bits and configurable clocks in the same
> register.
> 
> Signed-off-by: Simon Arlott <simon@fire.lp0.eu>

Acked-by: Rob Herring <robh@kernel.org>

> ---
> v2: Added clock-indices, clock-output-names (from clock-bindings.txt),
>     these are required properties.
> 
> v1: Renamed from BCM63xx to BCM6345.
> 
>  .../bindings/clock/brcm,bcm6345-gate-clk.txt       | 62 ++++++++++++++++++++++
>  1 file changed, 62 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/clock/brcm,bcm6345-gate-clk.txt
> 
> diff --git a/Documentation/devicetree/bindings/clock/brcm,bcm6345-gate-clk.txt b/Documentation/devicetree/bindings/clock/brcm,bcm6345-gate-clk.txt
> new file mode 100644
> index 0000000..a6e264c
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/clock/brcm,bcm6345-gate-clk.txt
> @@ -0,0 +1,62 @@
> +Broadcom BCM6345 clocks
> +
> +This binding uses the common clock binding:
> +	Documentation/devicetree/bindings/clock/clock-bindings.txt
> +
> +The BCM6345 contains clocks gated with a register. Clocks are indexed
> +by bits in the register and are active high. Most MIPS-based BCM63xx
> +SoCs have a clock gating set of registers, but some have clock gate bits
> +interleaved with other status bits and configurable clocks in the same
> +register.
> +
> +Required properties:
> +- compatible:         Should be "brcm,bcm<soc>-gate-clk", "brcm,bcm6345-gate-clk"
> +- #clock-cells:       Should be <1>.
> +- regmap:             The register map phandle
> +- offset:             Offset in the register map for the clock register (in bytes)
> +- clocks:             The external oscillator clock phandle
> +- clock-indices:      The bits in the register used for gated clocks.
> +- clock-output-names: Should be a list of strings of clock output signal
> +                      names indexed by the clock indices.
> +
> +Example:
> +
> +periph_clk: periph_clk {
> +	compatible = "brcm,bcm63168-gate-clk", "brcm,bcm6345-gate-clk";
> +	regmap = <&periph_cntl>;
> +	offset = <0x4>;
> +
> +	#clock-cells = <1>;
> +	clock-indices =
> +		<1>,          <2>,        <3>,       <4>,     <5>,
> +		<6>,          <7>,        <8>,       <9>,     <10>,
> +		<11>,         <12>,       <13>,      <14>,    <15>,
> +		<16>,         <17>,       <18>,      <19>,    <20>,
> +		<27>,         <31>;
> +	clock-output-names =
> +		"vdsl_qproc", "vdsl_afe", "vdsl",    "mips",  "wlan_ocp",
> +		"dect",       "fap0",     "fap1",    "sar",   "robosw",
> +		"pcm",        "usbd",     "usbh",    "ipsec", "spi",
> +		"hsspi",      "pcie",     "phymips", "gmac",  "nand",
> +		"tbus",       "robosw250";
> +};
> +
> +timer_clk: timer_clk {
> +	compatible = "brcm,bcm63168-gate-clk", "brcm,bcm6345-gate-clk";
> +	regmap = <&timer_cntl>;
> +	offset = <0x4>;
> +
> +	#clock-cells = <1>;
> +	clock-indices = <17>, <18>;
> +	clock-output-names = "uto_extin", "usb_ref";
> +};
> +
> +ehci0: usb@10002500 {
> +	compatible = "brcm,bcm63168-ehci", "brcm,bcm6345-ehci", "generic-ehci";
> +	reg = <0x10002500 0x100>;
> +	big-endian;
> +	interrupt-parent = <&periph_intc>;
> +	interrupts = <10>;
> +	clocks = <&periph_clk 13>, <&timer_clk 18>;
> +	phys = <&usbh>;
> +};
> -- 
> 2.1.4
> 
> -- 
> Simon Arlott

^ permalink raw reply	[flat|nested] 5+ messages in thread

* Re: [PATCH linux-next (v2) 1/2] clk: Add brcm, bcm6345-gate-clk device tree binding
  2015-12-10 21:49 [PATCH linux-next (v2) 1/2] clk: Add brcm,bcm6345-gate-clk device tree binding Simon Arlott
  2015-12-10 21:50 ` [PATCH linux-next (v2) 2/2] clk: bcm6345: Add BCM6345 gated clock support Simon Arlott
  2015-12-11  3:48 ` [PATCH linux-next (v2) 1/2] clk: Add brcm,bcm6345-gate-clk device tree binding Rob Herring
@ 2016-01-01  7:16 ` Michael Turquette
  2 siblings, 0 replies; 5+ messages in thread
From: Michael Turquette @ 2016-01-01  7:16 UTC (permalink / raw)
  To: Simon Arlott, Stephen Boyd, Kevin Cernekee, Florian Fainelli, devicetree
  Cc: Linux Kernel Mailing List, linux-clk, linux-mips, Rob Herring,
	Pawel Moll, Mark Rutland, Ian Campbell, Kumar Gala, Jonas Gorski

Hi Simon,

Quoting Simon Arlott (2015-12-10 13:49:21)
> +periph_clk: periph_clk {
> +       compatible = "brcm,bcm63168-gate-clk", "brcm,bcm6345-gate-clk";
> +       regmap = <&periph_cntl>;
> +       offset = <0x4>;
> +
> +       #clock-cells = <1>;
> +       clock-indices =
> +               <1>,          <2>,        <3>,       <4>,     <5>,
> +               <6>,          <7>,        <8>,       <9>,     <10>,
> +               <11>,         <12>,       <13>,      <14>,    <15>,
> +               <16>,         <17>,       <18>,      <19>,    <20>,
> +               <27>,         <31>;
> +       clock-output-names =
> +               "vdsl_qproc", "vdsl_afe", "vdsl",    "mips",  "wlan_ocp",
> +               "dect",       "fap0",     "fap1",    "sar",   "robosw",
> +               "pcm",        "usbd",     "usbh",    "ipsec", "spi",
> +               "hsspi",      "pcie",     "phymips", "gmac",  "nand",
> +               "tbus",       "robosw250";

Why is clock-output-names required? Because you don't have any clock
data in your driver? Or is there another reason?

FYI, I'm not a fan of clock-output-names, and prefer for the clk
consumer devices to specify the clock-names property.

Another question, is it correct that this binding requires a DT node for
every register that contains clock control bits? If so, I'm skeptical of
that approach. What if you have a clock controller IP block on a future
soc that has several registers worth of clock controls?

Regards,
Mike

> +};
> +
> +timer_clk: timer_clk {
> +       compatible = "brcm,bcm63168-gate-clk", "brcm,bcm6345-gate-clk";
> +       regmap = <&timer_cntl>;
> +       offset = <0x4>;
> +
> +       #clock-cells = <1>;
> +       clock-indices = <17>, <18>;
> +       clock-output-names = "uto_extin", "usb_ref";
> +};
> +
> +ehci0: usb@10002500 {
> +       compatible = "brcm,bcm63168-ehci", "brcm,bcm6345-ehci", "generic-ehci";
> +       reg = <0x10002500 0x100>;
> +       big-endian;
> +       interrupt-parent = <&periph_intc>;
> +       interrupts = <10>;
> +       clocks = <&periph_clk 13>, <&timer_clk 18>;
> +       phys = <&usbh>;
> +};
> -- 
> 2.1.4
> 
> -- 
> Simon Arlott

^ permalink raw reply	[flat|nested] 5+ messages in thread

* Re: [PATCH linux-next (v2) 2/2] clk: bcm6345: Add BCM6345 gated clock support
  2015-12-10 21:50 ` [PATCH linux-next (v2) 2/2] clk: bcm6345: Add BCM6345 gated clock support Simon Arlott
@ 2016-01-01 23:40   ` Michael Turquette
  0 siblings, 0 replies; 5+ messages in thread
From: Michael Turquette @ 2016-01-01 23:40 UTC (permalink / raw)
  To: Simon Arlott, Stephen Boyd, Kevin Cernekee, Florian Fainelli, devicetree
  Cc: Linux Kernel Mailing List, linux-clk, linux-mips, Rob Herring,
	Pawel Moll, Mark Rutland, Ian Campbell, Kumar Gala, Jonas Gorski

Hi Simon,

Quoting Simon Arlott (2015-12-10 13:50:59)
> +#define to_clk_bcm6345(_hw) container_of(_hw, struct clk_bcm6345, hw)
> +
> +static int clk_bcm6345_enable(struct clk_hw *hw)
> +{
> +       struct clk_bcm6345 *gate = to_clk_bcm6345(hw);
> +
> +       return regmap_write_bits(gate->map, gate->offset,
> +                                       gate->mask, gate->mask);

Does your regmap hold a spinlock or mutex? If a mutex then this should
be a .prepare callback instead of .enable. If it's a spinlock then
nothing to see here, move along.

> +}
> +
> +static void clk_bcm6345_disable(struct clk_hw *hw)
> +{
> +       struct clk_bcm6345 *gate = to_clk_bcm6345(hw);
> +
> +       regmap_write_bits(gate->map, gate->offset,
> +                                       gate->mask, 0);
> +}
> +
> +static int clk_bcm6345_is_enabled(struct clk_hw *hw)
> +{
> +       struct clk_bcm6345 *gate = to_clk_bcm6345(hw);
> +       unsigned int val;
> +       int ret;
> +
> +       ret = regmap_read(gate->map, gate->offset, &val);
> +       if (ret)
> +               return ret;
> +
> +       val &= gate->mask;
> +
> +       return val ? 1 : 0;
> +}
> +
> +const struct clk_ops clk_bcm6345_ops = {
> +       .enable = clk_bcm6345_enable,
> +       .disable = clk_bcm6345_disable,
> +       .is_enabled = clk_bcm6345_is_enabled,
> +};
> +
> +static struct clk * __init of_bcm6345_clk_register(const char *parent_name,
> +       const char *clk_name, struct regmap *map, u32 offset, u32 mask)
> +{
> +       struct clk_bcm6345 *gate;
> +       struct clk_init_data init;
> +       struct clk *ret;
> +
> +       gate = kzalloc(sizeof(*gate), GFP_KERNEL);
> +       if (!gate)
> +               return ERR_PTR(-ENOMEM);
> +
> +       init.name = clk_name;
> +       init.ops = &clk_bcm6345_ops;
> +       init.flags = CLK_IS_BASIC;

Why is CLK_IS_BASIC set?

> +       init.parent_names = (parent_name ? &parent_name : NULL);
> +       init.num_parents = (parent_name ? 1 : 0);
> +       gate->hw.init = &init;
> +       gate->map = map;
> +       gate->offset = offset;
> +       gate->mask = mask;
> +
> +       ret = clk_register(NULL, &gate->hw);
> +       if (IS_ERR(ret))
> +               kfree(gate);
> +
> +       return ret;
> +}
> +
> +static void __init of_bcm6345_clk_setup(struct device_node *node)
> +{
> +       struct clk_onecell_data *clk_data;
> +       const char *parent_name = NULL;
> +       struct regmap *map;
> +       u32 offset;
> +       unsigned int clocks = 0;
> +       int i;
> +
> +       clk_data = kzalloc(sizeof(*clk_data), GFP_KERNEL);
> +       if (!clk_data)
> +               return;
> +
> +       clk_data->clk_num = 32;
> +       clk_data->clks = kmalloc_array(clk_data->clk_num,
> +               sizeof(*clk_data->clks), GFP_KERNEL);
> +
> +       for (i = 0; i < clk_data->clk_num; i++)
> +               clk_data->clks[i] = ERR_PTR(-ENODEV);
> +
> +       if (of_clk_get_parent_count(node) > 0)
> +               parent_name = of_clk_get_parent_name(node, 0);
> +
> +       map = syscon_regmap_lookup_by_phandle(node, "regmap");
> +       if (IS_ERR(map)) {
> +               pr_err("%s: regmap lookup error %ld\n",
> +                       node->full_name, PTR_ERR(map));
> +               goto out;
> +       }
> +
> +       if (of_property_read_u32(node, "offset", &offset)) {
> +               pr_err("%s: offset not specified\n", node->full_name);
> +               goto out;
> +       }
> +
> +       /* clks[] is sparse, indexed by bit, maximum clocks checked using i */
> +       for (i = 0; i < clk_data->clk_num; i++) {
> +               u32 bit;
> +               const char *clk_name;
> +
> +               if (of_property_read_u32_index(node, "clock-indices",
> +                               i, &bit))
> +                       goto out;
> +
> +               if (of_property_read_string_index(node, "clock-output-names",
> +                               i, &clk_name))
> +                       goto out;
> +
> +               if (bit >= clk_data->clk_num) {
> +                       pr_err("%s: clock bit %u out of range\n",
> +                               node->full_name, bit);
> +                       continue;
> +               }
> +
> +               if (!IS_ERR(clk_data->clks[bit])) {
> +                       pr_err("%s: clock bit %u already exists\n",
> +                               node->full_name, bit);
> +                       continue;
> +               }
> +
> +               clk_data->clks[bit] = of_bcm6345_clk_register(parent_name,
> +                                       clk_name, map, offset, BIT(bit));
> +               if (!IS_ERR(clk_data->clks[bit]))
> +                       clocks++;
> +       }
> +
> +out:
> +       if (clocks) {
> +               of_clk_add_provider(node, of_clk_src_onecell_get, clk_data);
> +               pr_info("%s: registered %u clocks\n", node->name, clocks);
> +       } else {
> +               kfree(clk_data->clks);
> +               kfree(clk_data);
> +       }
> +}
> +
> +CLK_OF_DECLARE(bcm6345_clk, "brcm,bcm6345-gate-clk", of_bcm6345_clk_setup);

Please do not use CLK_OF_DECLARE unless there is a good reason. Ideally
this should be a platform_driver.

Regards,
Mike

> -- 
> 2.1.4
> 
> -- 
> Simon Arlott

^ permalink raw reply	[flat|nested] 5+ messages in thread

end of thread, other threads:[~2016-01-01 23:53 UTC | newest]

Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2015-12-10 21:49 [PATCH linux-next (v2) 1/2] clk: Add brcm,bcm6345-gate-clk device tree binding Simon Arlott
2015-12-10 21:50 ` [PATCH linux-next (v2) 2/2] clk: bcm6345: Add BCM6345 gated clock support Simon Arlott
2016-01-01 23:40   ` Michael Turquette
2015-12-11  3:48 ` [PATCH linux-next (v2) 1/2] clk: Add brcm,bcm6345-gate-clk device tree binding Rob Herring
2016-01-01  7:16 ` [PATCH linux-next (v2) 1/2] clk: Add brcm, bcm6345-gate-clk " Michael Turquette

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