diff mbox series

[RFC,07/16] clk: hifiberry-dacpro: initial import

Message ID 20200409195841.18901-8-pierre-louis.bossart@linux.intel.com (mailing list archive)
State RFC, archived
Headers show
Series ASoC/SOF/clk/gpio/dt: add Hifiberry DAC+ PRO support | expand

Commit Message

Pierre-Louis Bossart April 9, 2020, 7:58 p.m. UTC
From: Daniel Matuschek <daniel@hifiberry.com>

This patch imports the clock code from the Raspberry v5.5-y tree. The
ASoC machine driver initially present in this patch was dropped. The
comments are also dropped but all sign-offs are kept below. The patch
authorship was modified with explicit permission from Daniel Matuschek
to make sure it matches the Signed-off tag.

This patch generates a lot of checkpatch.pl warnings that are
corrected in follow-up patches.

Signed-off-by: DigitalDreamtime <clive.messer@digitaldreamtime.co.uk>
Signed-off-by: Daniel Matuschek <daniel@hifiberry.com>
Signed-off-by: Matthias Reichl <hias@horus.com>
Signed-off-by: Hui Wang <hui.wang@canonical.com>
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
---
 drivers/clk/Kconfig                |   3 +
 drivers/clk/Makefile               |   1 +
 drivers/clk/clk-hifiberry-dacpro.c | 160 +++++++++++++++++++++++++++++
 3 files changed, 164 insertions(+)
 create mode 100644 drivers/clk/clk-hifiberry-dacpro.c

Comments

Andy Shevchenko April 14, 2020, 5:31 p.m. UTC | #1
On Thu, Apr 09, 2020 at 02:58:32PM -0500, Pierre-Louis Bossart wrote:
> From: Daniel Matuschek <daniel@hifiberry.com>
> 
> This patch imports the clock code from the Raspberry v5.5-y tree. The
> ASoC machine driver initially present in this patch was dropped. The
> comments are also dropped but all sign-offs are kept below. The patch
> authorship was modified with explicit permission from Daniel Matuschek
> to make sure it matches the Signed-off tag.
> 
> This patch generates a lot of checkpatch.pl warnings that are
> corrected in follow-up patches.

I guess it will be waste of time to review this part without squashing it first.
Pierre-Louis Bossart April 14, 2020, 6:09 p.m. UTC | #2
On 4/14/20 12:31 PM, Andy Shevchenko wrote:
> On Thu, Apr 09, 2020 at 02:58:32PM -0500, Pierre-Louis Bossart wrote:
>> From: Daniel Matuschek <daniel@hifiberry.com>
>>
>> This patch imports the clock code from the Raspberry v5.5-y tree. The
>> ASoC machine driver initially present in this patch was dropped. The
>> comments are also dropped but all sign-offs are kept below. The patch
>> authorship was modified with explicit permission from Daniel Matuschek
>> to make sure it matches the Signed-off tag.
>>
>> This patch generates a lot of checkpatch.pl warnings that are
>> corrected in follow-up patches.
> 
> I guess it will be waste of time to review this part without squashing it first.

I wasn't sure if squashing was desired, so kept all my changes separate. 
There are some changes from the legacy clk to the clk_hw parts plus 
introduction of ACPI support that are easier to review if kept separate. 
Maybe I should have squashed the cosmetic parts in patch8, and kept the 
functional changes as separate patches.
Andy Shevchenko April 15, 2020, 10 a.m. UTC | #3
On Tue, Apr 14, 2020 at 01:09:28PM -0500, Pierre-Louis Bossart wrote:
> On 4/14/20 12:31 PM, Andy Shevchenko wrote:
> > On Thu, Apr 09, 2020 at 02:58:32PM -0500, Pierre-Louis Bossart wrote:
> > > From: Daniel Matuschek <daniel@hifiberry.com>
> > > 
> > > This patch imports the clock code from the Raspberry v5.5-y tree. The
> > > ASoC machine driver initially present in this patch was dropped. The
> > > comments are also dropped but all sign-offs are kept below. The patch
> > > authorship was modified with explicit permission from Daniel Matuschek
> > > to make sure it matches the Signed-off tag.
> > > 
> > > This patch generates a lot of checkpatch.pl warnings that are
> > > corrected in follow-up patches.
> > 
> > I guess it will be waste of time to review this part without squashing it first.
> 
> I wasn't sure if squashing was desired, so kept all my changes separate.

At the end, yes. It's a new contribution that can be at least cleaned before
hands to more-or-less acceptable point. With so many subtle issues it's not
good that we dump an ugly code outside of drivers/staging.

> There are some changes from the legacy clk to the clk_hw parts plus
> introduction of ACPI support that are easier to review if kept separate.

Yes, for review purposes it's okay.

You always can put your name as a SoB + Co-developed-by tag or give credits to
other people in the commit message differently (depending to amount of work
they do vs. yours).

> Maybe I should have squashed the cosmetic parts in patch8, and kept the
> functional changes as separate patches.

Use a common sense, you know your work better than me :-)
Just explain this in cover letter (like you do for this version).
diff mbox series

Patch

diff --git a/drivers/clk/Kconfig b/drivers/clk/Kconfig
index bcb257baed06..6bfffc99e3fd 100644
--- a/drivers/clk/Kconfig
+++ b/drivers/clk/Kconfig
@@ -70,6 +70,9 @@  config COMMON_CLK_HI655X
 	  multi-function device has one fixed-rate oscillator, clocked
 	  at 32KHz.
 
+config COMMON_CLK_HIFIBERRY_DACPRO
+	tristate
+
 config COMMON_CLK_SCMI
 	tristate "Clock driver controlled via SCMI interface"
 	depends on ARM_SCMI_PROTOCOL || COMPILE_TEST
diff --git a/drivers/clk/Makefile b/drivers/clk/Makefile
index f4169cc2fd31..43ae7596de7b 100644
--- a/drivers/clk/Makefile
+++ b/drivers/clk/Makefile
@@ -36,6 +36,7 @@  obj-$(CONFIG_MACH_ASPEED_G6)		+= clk-ast2600.o
 obj-$(CONFIG_ARCH_HIGHBANK)		+= clk-highbank.o
 obj-$(CONFIG_CLK_HSDK)			+= clk-hsdk-pll.o
 obj-$(CONFIG_COMMON_CLK_LOCHNAGAR)	+= clk-lochnagar.o
+obj-$(CONFIG_COMMON_CLK_HIFIBERRY_DACPRO)	+= clk-hifiberry-dacpro.o
 obj-$(CONFIG_COMMON_CLK_MAX77686)	+= clk-max77686.o
 obj-$(CONFIG_COMMON_CLK_MAX9485)	+= clk-max9485.o
 obj-$(CONFIG_ARCH_MILBEAUT_M10V)	+= clk-milbeaut.o
diff --git a/drivers/clk/clk-hifiberry-dacpro.c b/drivers/clk/clk-hifiberry-dacpro.c
new file mode 100644
index 000000000000..9e2634465823
--- /dev/null
+++ b/drivers/clk/clk-hifiberry-dacpro.c
@@ -0,0 +1,160 @@ 
+/*
+ * Clock Driver for HiFiBerry DAC Pro
+ *
+ * Author: Stuart MacLean
+ *         Copyright 2015
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ */
+
+#include <linux/clk-provider.h>
+#include <linux/clkdev.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/slab.h>
+#include <linux/platform_device.h>
+
+/* Clock rate of CLK44EN attached to GPIO6 pin */
+#define CLK_44EN_RATE 22579200UL
+/* Clock rate of CLK48EN attached to GPIO3 pin */
+#define CLK_48EN_RATE 24576000UL
+
+/**
+ * struct hifiberry_dacpro_clk - Common struct to the HiFiBerry DAC Pro
+ * @hw: clk_hw for the common clk framework
+ * @mode: 0 => CLK44EN, 1 => CLK48EN
+ */
+struct clk_hifiberry_hw {
+	struct clk_hw hw;
+	uint8_t mode;
+};
+
+#define to_hifiberry_clk(_hw) container_of(_hw, struct clk_hifiberry_hw, hw)
+
+static const struct of_device_id clk_hifiberry_dacpro_dt_ids[] = {
+	{ .compatible = "hifiberry,dacpro-clk",},
+	{ }
+};
+MODULE_DEVICE_TABLE(of, clk_hifiberry_dacpro_dt_ids);
+
+static unsigned long clk_hifiberry_dacpro_recalc_rate(struct clk_hw *hw,
+	unsigned long parent_rate)
+{
+	return (to_hifiberry_clk(hw)->mode == 0) ? CLK_44EN_RATE :
+		CLK_48EN_RATE;
+}
+
+static long clk_hifiberry_dacpro_round_rate(struct clk_hw *hw,
+	unsigned long rate, unsigned long *parent_rate)
+{
+	long actual_rate;
+
+	if (rate <= CLK_44EN_RATE) {
+		actual_rate = (long)CLK_44EN_RATE;
+	} else if (rate >= CLK_48EN_RATE) {
+		actual_rate = (long)CLK_48EN_RATE;
+	} else {
+		long diff44Rate = (long)(rate - CLK_44EN_RATE);
+		long diff48Rate = (long)(CLK_48EN_RATE - rate);
+
+		if (diff44Rate < diff48Rate)
+			actual_rate = (long)CLK_44EN_RATE;
+		else
+			actual_rate = (long)CLK_48EN_RATE;
+	}
+	return actual_rate;
+}
+
+
+static int clk_hifiberry_dacpro_set_rate(struct clk_hw *hw,
+	unsigned long rate, unsigned long parent_rate)
+{
+	unsigned long actual_rate;
+	struct clk_hifiberry_hw *clk = to_hifiberry_clk(hw);
+
+	actual_rate = (unsigned long)clk_hifiberry_dacpro_round_rate(hw, rate,
+		&parent_rate);
+	clk->mode = (actual_rate == CLK_44EN_RATE) ? 0 : 1;
+	return 0;
+}
+
+
+const struct clk_ops clk_hifiberry_dacpro_rate_ops = {
+	.recalc_rate = clk_hifiberry_dacpro_recalc_rate,
+	.round_rate = clk_hifiberry_dacpro_round_rate,
+	.set_rate = clk_hifiberry_dacpro_set_rate,
+};
+
+static int clk_hifiberry_dacpro_probe(struct platform_device *pdev)
+{
+	int ret;
+	struct clk_hifiberry_hw *proclk;
+	struct clk *clk;
+	struct device *dev;
+	struct clk_init_data init;
+
+	dev = &pdev->dev;
+
+	proclk = kzalloc(sizeof(struct clk_hifiberry_hw), GFP_KERNEL);
+	if (!proclk)
+		return -ENOMEM;
+
+	init.name = "clk-hifiberry-dacpro";
+	init.ops = &clk_hifiberry_dacpro_rate_ops;
+	init.flags = 0;
+	init.parent_names = NULL;
+	init.num_parents = 0;
+
+	proclk->mode = 0;
+	proclk->hw.init = &init;
+
+	clk = devm_clk_register(dev, &proclk->hw);
+	if (!IS_ERR(clk)) {
+		ret = of_clk_add_provider(dev->of_node, of_clk_src_simple_get,
+			clk);
+	} else {
+		dev_err(dev, "Fail to register clock driver\n");
+		kfree(proclk);
+		ret = PTR_ERR(clk);
+	}
+	return ret;
+}
+
+static int clk_hifiberry_dacpro_remove(struct platform_device *pdev)
+{
+	of_clk_del_provider(pdev->dev.of_node);
+	return 0;
+}
+
+static struct platform_driver clk_hifiberry_dacpro_driver = {
+	.probe = clk_hifiberry_dacpro_probe,
+	.remove = clk_hifiberry_dacpro_remove,
+	.driver = {
+		.name = "clk-hifiberry-dacpro",
+		.of_match_table = clk_hifiberry_dacpro_dt_ids,
+	},
+};
+
+static int __init clk_hifiberry_dacpro_init(void)
+{
+	return platform_driver_register(&clk_hifiberry_dacpro_driver);
+}
+core_initcall(clk_hifiberry_dacpro_init);
+
+static void __exit clk_hifiberry_dacpro_exit(void)
+{
+	platform_driver_unregister(&clk_hifiberry_dacpro_driver);
+}
+module_exit(clk_hifiberry_dacpro_exit);
+
+MODULE_DESCRIPTION("HiFiBerry DAC Pro clock driver");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:clk-hifiberry-dacpro");