diff mbox series

[v4,4/5] clk: twl: add clock driver for TWL6032

Message ID 20230916100515.1650336-5-andreas@kemnade.info (mailing list archive)
State New, archived
Headers show
Series ARM: omap: omap4-embt2ws: 32K clock for WLAN | expand

Commit Message

Andreas Kemnade Sept. 16, 2023, 10:05 a.m. UTC
The TWL6032 has some clock outputs which are controlled like
fixed-voltage regulators, in some drivers for these chips
found in the wild, just the regulator api is abused for controlling
them, so simply use something similar to the regulator functions.
Due to a lack of hardware available for testing, leave out the
TWL6030-specific part of those functions.

Signed-off-by: Andreas Kemnade <andreas@kemnade.info>
---
 drivers/clk/Kconfig   |   9 ++
 drivers/clk/Makefile  |   1 +
 drivers/clk/clk-twl.c | 197 ++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 207 insertions(+)
 create mode 100644 drivers/clk/clk-twl.c

Comments

Andreas Kemnade Oct. 13, 2023, 6:08 a.m. UTC | #1
On Sat, 16 Sep 2023 12:05:14 +0200
Andreas Kemnade <andreas@kemnade.info> wrote:

> The TWL6032 has some clock outputs which are controlled like
> fixed-voltage regulators, in some drivers for these chips
> found in the wild, just the regulator api is abused for controlling
> them, so simply use something similar to the regulator functions.
> Due to a lack of hardware available for testing, leave out the
> TWL6030-specific part of those functions.
> 
> Signed-off-by: Andreas Kemnade <andreas@kemnade.info>
> ---
ping...

anything left to do here?

Regards,
Andreas
Stephen Boyd Oct. 19, 2023, 1:20 a.m. UTC | #2
Quoting Andreas Kemnade (2023-09-16 03:05:14)
> The TWL6032 has some clock outputs which are controlled like
> fixed-voltage regulators, in some drivers for these chips
> found in the wild, just the regulator api is abused for controlling
> them, so simply use something similar to the regulator functions.
> Due to a lack of hardware available for testing, leave out the
> TWL6030-specific part of those functions.
> 
> Signed-off-by: Andreas Kemnade <andreas@kemnade.info>
> ---

Did you want me to pick this up in clk tree?

Acked-by: Stephen Boyd <sboyd@kernel.org>
Andreas Kemnade Oct. 19, 2023, 7:18 a.m. UTC | #3
Am Wed, 18 Oct 2023 18:20:22 -0700
schrieb Stephen Boyd <sboyd@kernel.org>:

> Quoting Andreas Kemnade (2023-09-16 03:05:14)
> > The TWL6032 has some clock outputs which are controlled like
> > fixed-voltage regulators, in some drivers for these chips
> > found in the wild, just the regulator api is abused for controlling
> > them, so simply use something similar to the regulator functions.
> > Due to a lack of hardware available for testing, leave out the
> > TWL6030-specific part of those functions.
> > 
> > Signed-off-by: Andreas Kemnade <andreas@kemnade.info>
> > ---  
> 
> Did you want me to pick this up in clk tree?
> 
> Acked-by: Stephen Boyd <sboyd@kernel.org>
> 
Well, Lee has picked up 1-3 of this series, so I think it is a good idea
if you take it. I do not think it will make things any easier if it goes
through Tony's tree because part 5 is a bit tricky.
If picked up independently (of the whole set and not only part 4), there
will be a range of commits were WLAN will not work at all instead of
basically working randomly by the clock is enabled for some reason (can
happen if warm-booted from the vendor kernel).

So IMHO for part 5 we have to decide wether to decide if above is
considered to break bisectability and take the patch for 6.8 or
ignore that and take it for 6.7.

But no matter how we decide, that should not affect the route for this
part 4. So it is a good idea to have it through the clk tree.

Regrads,
Andreas
Stephen Boyd Oct. 19, 2023, 11:43 p.m. UTC | #4
Quoting Andreas Kemnade (2023-09-16 03:05:14)
> The TWL6032 has some clock outputs which are controlled like
> fixed-voltage regulators, in some drivers for these chips
> found in the wild, just the regulator api is abused for controlling
> them, so simply use something similar to the regulator functions.
> Due to a lack of hardware available for testing, leave out the
> TWL6030-specific part of those functions.
> 
> Signed-off-by: Andreas Kemnade <andreas@kemnade.info>
> ---

Applied to clk-next
diff mbox series

Patch

diff --git a/drivers/clk/Kconfig b/drivers/clk/Kconfig
index c30099866174d..3944f081ebade 100644
--- a/drivers/clk/Kconfig
+++ b/drivers/clk/Kconfig
@@ -277,6 +277,15 @@  config COMMON_CLK_S2MPS11
 	  clock. These multi-function devices have two (S2MPS14) or three
 	  (S2MPS11, S5M8767) fixed-rate oscillators, clocked at 32KHz each.
 
+config CLK_TWL
+	tristate "Clock driver for the TWL PMIC family"
+	depends on TWL4030_CORE
+	help
+	  Enable support for controlling the clock resources on TWL family
+	  PMICs. These devices have some 32K clock outputs which can be
+	  controlled by software. For now, only the TWL6032 clocks are
+	  supported.
+
 config CLK_TWL6040
 	tristate "External McPDM functional clock from twl6040"
 	depends on TWL6040_CORE
diff --git a/drivers/clk/Makefile b/drivers/clk/Makefile
index 18969cbd4bb1e..86e46adcb619c 100644
--- a/drivers/clk/Makefile
+++ b/drivers/clk/Makefile
@@ -72,6 +72,7 @@  obj-$(CONFIG_COMMON_CLK_STM32H7)	+= clk-stm32h7.o
 obj-$(CONFIG_COMMON_CLK_STM32MP157)	+= clk-stm32mp1.o
 obj-$(CONFIG_COMMON_CLK_TPS68470)      += clk-tps68470.o
 obj-$(CONFIG_CLK_TWL6040)		+= clk-twl6040.o
+obj-$(CONFIG_CLK_TWL)			+= clk-twl.o
 obj-$(CONFIG_ARCH_VT8500)		+= clk-vt8500.o
 obj-$(CONFIG_COMMON_CLK_RS9_PCIE)	+= clk-renesas-pcie.o
 obj-$(CONFIG_COMMON_CLK_SI521XX)	+= clk-si521xx.o
diff --git a/drivers/clk/clk-twl.c b/drivers/clk/clk-twl.c
new file mode 100644
index 0000000000000..eab9d3c8ed8ae
--- /dev/null
+++ b/drivers/clk/clk-twl.c
@@ -0,0 +1,197 @@ 
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Clock driver for twl device.
+ *
+ * inspired by the driver for the Palmas device
+ */
+
+#include <linux/clk-provider.h>
+#include <linux/mfd/twl.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+
+#define VREG_STATE              2
+#define TWL6030_CFG_STATE_OFF   0x00
+#define TWL6030_CFG_STATE_ON    0x01
+#define TWL6030_CFG_STATE_MASK  0x03
+
+struct twl_clock_info {
+	struct device *dev;
+	u8 base;
+	struct clk_hw hw;
+};
+
+static inline int
+twlclk_read(struct twl_clock_info *info, unsigned int slave_subgp,
+	    unsigned int offset)
+{
+	u8 value;
+	int status;
+
+	status = twl_i2c_read_u8(slave_subgp, &value,
+				 info->base + offset);
+	return (status < 0) ? status : value;
+}
+
+static inline int
+twlclk_write(struct twl_clock_info *info, unsigned int slave_subgp,
+	     unsigned int offset, u8 value)
+{
+	return twl_i2c_write_u8(slave_subgp, value,
+				info->base + offset);
+}
+
+static inline struct twl_clock_info *to_twl_clks_info(struct clk_hw *hw)
+{
+	return container_of(hw, struct twl_clock_info, hw);
+}
+
+static unsigned long twl_clks_recalc_rate(struct clk_hw *hw,
+					  unsigned long parent_rate)
+{
+	return 32768;
+}
+
+static int twl6032_clks_prepare(struct clk_hw *hw)
+{
+	struct twl_clock_info *cinfo = to_twl_clks_info(hw);
+	int ret;
+
+	ret = twlclk_write(cinfo, TWL_MODULE_PM_RECEIVER, VREG_STATE,
+			   TWL6030_CFG_STATE_ON);
+	if (ret < 0)
+		dev_err(cinfo->dev, "clk prepare failed\n");
+
+	return ret;
+}
+
+static void twl6032_clks_unprepare(struct clk_hw *hw)
+{
+	struct twl_clock_info *cinfo = to_twl_clks_info(hw);
+	int ret;
+
+	ret = twlclk_write(cinfo, TWL_MODULE_PM_RECEIVER, VREG_STATE,
+			   TWL6030_CFG_STATE_OFF);
+	if (ret < 0)
+		dev_err(cinfo->dev, "clk unprepare failed\n");
+}
+
+static int twl6032_clks_is_prepared(struct clk_hw *hw)
+{
+	struct twl_clock_info *cinfo = to_twl_clks_info(hw);
+	int val;
+
+	val = twlclk_read(cinfo, TWL_MODULE_PM_RECEIVER, VREG_STATE);
+	if (val < 0) {
+		dev_err(cinfo->dev, "clk read failed\n");
+		return val;
+	}
+
+	val &= TWL6030_CFG_STATE_MASK;
+
+	return val == TWL6030_CFG_STATE_ON;
+}
+
+static const struct clk_ops twl6032_clks_ops = {
+	.prepare	= twl6032_clks_prepare,
+	.unprepare	= twl6032_clks_unprepare,
+	.is_prepared	= twl6032_clks_is_prepared,
+	.recalc_rate	= twl_clks_recalc_rate,
+};
+
+struct twl_clks_data {
+	struct clk_init_data init;
+	u8 base;
+};
+
+static const struct twl_clks_data twl6032_clks[] = {
+	{
+		.init = {
+			.name = "clk32kg",
+			.ops = &twl6032_clks_ops,
+			.flags = CLK_IGNORE_UNUSED,
+		},
+		.base = 0x8C,
+	},
+	{
+		.init = {
+			.name = "clk32kaudio",
+			.ops = &twl6032_clks_ops,
+			.flags = CLK_IGNORE_UNUSED,
+		},
+		.base = 0x8F,
+	},
+	{
+		/* sentinel */
+	}
+};
+
+static int twl_clks_probe(struct platform_device *pdev)
+{
+	struct clk_hw_onecell_data *clk_data;
+	const struct twl_clks_data *hw_data;
+
+	struct twl_clock_info *cinfo;
+	int ret;
+	int i;
+	int count;
+
+	hw_data = twl6032_clks;
+	for (count = 0; hw_data[count].init.name; count++)
+		;
+
+	clk_data = devm_kzalloc(&pdev->dev,
+				struct_size(clk_data, hws, count),
+				GFP_KERNEL);
+	if (!clk_data)
+		return -ENOMEM;
+
+	clk_data->num = count;
+	cinfo = devm_kcalloc(&pdev->dev, count, sizeof(*cinfo), GFP_KERNEL);
+	if (!cinfo)
+		return -ENOMEM;
+
+	for (i = 0; i < count; i++) {
+		cinfo[i].base = hw_data[i].base;
+		cinfo[i].dev = &pdev->dev;
+		cinfo[i].hw.init = &hw_data[i].init;
+		ret = devm_clk_hw_register(&pdev->dev, &cinfo[i].hw);
+		if (ret) {
+			return dev_err_probe(&pdev->dev, ret,
+					     "Fail to register clock %s\n",
+					     hw_data[i].init.name);
+		}
+		clk_data->hws[i] = &cinfo[i].hw;
+	}
+
+	ret = devm_of_clk_add_hw_provider(&pdev->dev,
+					  of_clk_hw_onecell_get, clk_data);
+	if (ret < 0)
+		return dev_err_probe(&pdev->dev, ret,
+				     "Fail to add clock driver\n");
+
+	return 0;
+}
+
+static const struct platform_device_id twl_clks_id[] = {
+	{
+		.name = "twl6032-clk",
+	}, {
+		/* sentinel */
+	}
+};
+MODULE_DEVICE_TABLE(platform, twl_clks_id);
+
+static struct platform_driver twl_clks_driver = {
+	.driver = {
+		.name = "twl-clk",
+	},
+	.probe = twl_clks_probe,
+	.id_table = twl_clks_id,
+};
+
+module_platform_driver(twl_clks_driver);
+
+MODULE_DESCRIPTION("Clock driver for TWL Series Devices");
+MODULE_LICENSE("GPL");