diff mbox series

[v5,2/3] clk: meson: add a driver for the Meson8/8b/8m2 SDHC clock controller

Message ID 20200328003249.1248978-3-martin.blumenstingl@googlemail.com (mailing list archive)
State Superseded
Delegated to: Neil Armstrong
Headers show
Series Amlogic 32-bit Meson SoC SDHC MMC controller driver | expand

Commit Message

Martin Blumenstingl March 28, 2020, 12:32 a.m. UTC 
The SDHC (MMC) controller embeds a clock controller inside one of the
SDHC registers. The outputs of thisclock controller are dedicated to the
SDHC controller.

Implement a dedicated clock controller driver so we can keep all the
clock specific logic outside of the MMC controller driver. There is no
dedicated clock controller OF node because the hardware is a big SDHC IP
block with an embedded clock controller (so the .dts doesn't need a
separate clock controller node). Instead this driver re-uses the regmap
as registered by the (platform_device) parent.

Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
---
 drivers/clk/meson/Kconfig         |   9 ++
 drivers/clk/meson/Makefile        |   1 +
 drivers/clk/meson/meson-mx-sdhc.c | 212 ++++++++++++++++++++++++++++++
 3 files changed, 222 insertions(+)
 create mode 100644 drivers/clk/meson/meson-mx-sdhc.c

Comments

Jerome Brunet April 27, 2020, 8:41 a.m. UTC | #1 
On Sat 28 Mar 2020 at 01:32, Martin Blumenstingl <martin.blumenstingl@googlemail.com> wrote:

> The SDHC (MMC) controller embeds a clock controller inside one of the
> SDHC registers. The outputs of thisclock controller are dedicated to the
> SDHC controller.
>
> Implement a dedicated clock controller driver so we can keep all the
> clock specific logic outside of the MMC controller driver. There is no
> dedicated clock controller OF node because the hardware is a big SDHC IP
> block with an embedded clock controller (so the .dts doesn't need a
> separate clock controller node). Instead this driver re-uses the regmap
> as registered by the (platform_device) parent.
>
> Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
> ---
>  drivers/clk/meson/Kconfig         |   9 ++
>  drivers/clk/meson/Makefile        |   1 +
>  drivers/clk/meson/meson-mx-sdhc.c | 212 ++++++++++++++++++++++++++++++
>  3 files changed, 222 insertions(+)
>  create mode 100644 drivers/clk/meson/meson-mx-sdhc.c
>
> diff --git a/drivers/clk/meson/Kconfig b/drivers/clk/meson/Kconfig
> index dabeb435d067..8769335d2d46 100644
> --- a/drivers/clk/meson/Kconfig
> +++ b/drivers/clk/meson/Kconfig
> @@ -53,6 +53,15 @@ config COMMON_CLK_MESON8B
>  	  S805 (Meson8b) and S812 (Meson8m2) devices. Say Y if you
>  	  want peripherals and CPU frequency scaling to work.
>  
> +config COMMON_CLK_MESON_MX_SDHC
> +	tristate "Meson MX SDHC MMC Clock Controller Driver"
> +	depends on ARCH_MESON
> +	select COMMON_CLK_MESON_REGMAP
> +	help
> +	  Support for the SDHC clock controller on Amlogic Meson8/8b/8m2 SoCs
> +	  devices. Say Y or M if you want to use the SDHC MMC controller.
> +	  Otherwise say N.
> +
>  config COMMON_CLK_GXBB
>  	bool
>  	depends on ARCH_MESON
> diff --git a/drivers/clk/meson/Makefile b/drivers/clk/meson/Makefile
> index 6eca2a406ee3..b71c7ae78dbd 100644
> --- a/drivers/clk/meson/Makefile
> +++ b/drivers/clk/meson/Makefile
> @@ -19,3 +19,4 @@ obj-$(CONFIG_COMMON_CLK_AXG_AUDIO) += axg-audio.o
>  obj-$(CONFIG_COMMON_CLK_GXBB) += gxbb.o gxbb-aoclk.o
>  obj-$(CONFIG_COMMON_CLK_G12A) += g12a.o g12a-aoclk.o
>  obj-$(CONFIG_COMMON_CLK_MESON8B) += meson8b.o meson8-ddr.o
> +obj-$(CONFIG_COMMON_CLK_MESON_MX_SDHC) += meson-mx-sdhc.o
> diff --git a/drivers/clk/meson/meson-mx-sdhc.c b/drivers/clk/meson/meson-mx-sdhc.c
> new file mode 100644
> index 000000000000..b98a35d99f65
> --- /dev/null
> +++ b/drivers/clk/meson/meson-mx-sdhc.c
> @@ -0,0 +1,212 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +/*
> + * Amlogic Meson SDHC clock controller
> + *
> + * Copyright (C) 2019 Martin Blumenstingl <martin.blumenstingl@googlemail.com>
> + */
> +
> +#include <dt-bindings/clock/meson-mx-sdhc-clkc.h>
> +
> +#include <linux/clk-provider.h>
> +#include <linux/device.h>
> +#include <linux/module.h>
> +#include <linux/platform_device.h>
> +
> +#include "clk-regmap.h"
> +#include "clk-pll.h"

If you need the pll clocks, it should probably appear in the Kconfig
deps as well

> +
> +#define MESON_SDHC_CLKC			0x10
> +
> +static const struct clk_regmap meson_mx_sdhc_src_sel = {
> +	.data = &(struct clk_regmap_mux_data){
> +		.offset = MESON_SDHC_CLKC,
> +		.mask = 0x3,
> +		.shift = 16,
> +	},
> +	.hw.init = &(struct clk_init_data){
> +		.name = "sdhc_src_sel",
> +		.ops = &clk_regmap_mux_ops,
> +		.parent_data = (const struct clk_parent_data[]) {
> +			{ .fw_name = "clkin0", .index = -1, },
> +			{ .fw_name = "clkin1", .index = -1, },
> +			{ .fw_name = "clkin2", .index = -1, },
> +			{ .fw_name = "clkin3", .index = -1, },

When fw_name is specified, setting the index is not necessary

> +		},
> +		.num_parents = 4,
> +	},
> +};
> +
> +static const struct clk_div_table meson_mx_sdhc_div_table[] = {
> +	{ .div = 6, .val = 5, },
> +	{ .div = 8, .val = 7, },
> +	{ .div = 9, .val = 8, },
> +	{ .div = 10, .val = 9, },
> +	{ .div = 12, .val = 11, },
> +	{ .div = 16, .val = 15, },
> +	{ .div = 18, .val = 17, },
> +	{ .div = 34, .val = 33, },
> +	{ .div = 142, .val = 141, },
> +	{ .div = 850, .val = 849, },
> +	{ .div = 2126, .val = 2125, },
> +	{ .div = 4096, .val = 4095, },
> +	{ /* sentinel */ }
> +};
> +
> +static const struct clk_regmap meson_mx_sdhc_div = {
> +	.data = &(struct clk_regmap_div_data){
> +		.offset = MESON_SDHC_CLKC,
> +		.shift = 0,
> +		.width = 12,
> +		.table = meson_mx_sdhc_div_table,
> +	},
> +	.hw.init = &(struct clk_init_data){
> +		.name = "sdhc_div",
> +		.ops = &clk_regmap_divider_ops,
> +		.parent_data = (const struct clk_parent_data[]) {
> +			{ .name = "sdhc_src_sel", .index = -1, },

Any reason for using the lagacy names and not the clk_hw pointers ?
Same comment for the rest of the clocks

> +		},
> +		.num_parents = 1,
> +		.flags = CLK_SET_RATE_PARENT,
> +	},
> +};
> +
> +static const struct clk_regmap meson_mx_sdhc_mod_clk_en = {
> +	.data = &(struct clk_regmap_gate_data){
> +		.offset = MESON_SDHC_CLKC,
> +		.bit_idx = 15,
> +	},
> +	.hw.init = &(struct clk_init_data){
> +		.name = "sdhc_mod_clk_on",
> +		.ops = &clk_regmap_gate_ops,
> +		.parent_data = (const struct clk_parent_data[]) {
> +			{ .name = "sdhc_div", .index = -1, },
> +		},
> +		.num_parents = 1,
> +		.flags = CLK_SET_RATE_GATE,

Why can't the clock change rate unless gated ? Maybe you prefer to
change the rate in the mmc while clock is gated, but this is the
handling of the clock by the mmc driver, not a constraint of the actual
clock HW, isn't it ?

Also, this is a gate so I suppose the rate propagates through it ?
Can you explain why CLK_SET_RATE_PARENT is not set  ?

> +	},
> +};
> +
> +static const struct clk_regmap meson_mx_sdhc_tx_clk_en = {
> +	.data = &(struct clk_regmap_gate_data){
> +		.offset = MESON_SDHC_CLKC,
> +		.bit_idx = 14,
> +	},
> +	.hw.init = &(struct clk_init_data){
> +		.name = "sdhc_tx_clk_on",
> +		.ops = &clk_regmap_gate_ops,
> +		.parent_data = (const struct clk_parent_data[]) {
> +			{ .name = "sdhc_div", .index = -1, },
> +		},
> +		.num_parents = 1,
> +		.flags = CLK_SET_RATE_GATE,
> +	},
> +};
> +
> +static const struct clk_regmap meson_mx_sdhc_rx_clk_en = {
> +	.data = &(struct clk_regmap_gate_data){
> +		.offset = MESON_SDHC_CLKC,
> +		.bit_idx = 13,
> +	},
> +	.hw.init = &(struct clk_init_data){
> +		.name = "sdhc_rx_clk_on",
> +		.ops = &clk_regmap_gate_ops,
> +		.parent_data = (const struct clk_parent_data[]) {
> +			{ .name = "sdhc_div", .index = -1, },
> +		},
> +		.num_parents = 1,
> +		.flags = CLK_SET_RATE_PARENT | CLK_SET_RATE_GATE,

Ok so apparently you only want to set the rate through the RX clock.
You are free to call set_rate() only on this clock in the mmc driver.
However, I don't think this should reflect as clock constraints.

> +	},
> +};
> +
> +static const struct clk_regmap meson_mx_sdhc_sd_clk_en = {
> +	.data = &(struct clk_regmap_gate_data){
> +		.offset = MESON_SDHC_CLKC,
> +		.bit_idx = 12,
> +	},
> +	.hw.init = &(struct clk_init_data){
> +		.name = "sdhc_sd_clk_on",
> +		.ops = &clk_regmap_gate_ops,
> +		.parent_data = (const struct clk_parent_data[]) {
> +			{ .name = "sdhc_div", .index = -1, },
> +		},
> +		.num_parents = 1,
> +		.flags = CLK_SET_RATE_PARENT | CLK_SET_RATE_GATE,

... now I lost with these flags. I'm sure there is an idea related to
the mmc driver. Clockwise, I don't get it.

> +	},
> +};
> +
> +static const struct clk_regmap *meson_mx_sdhc_clk_regmaps[] = {
> +	[SDHC_CLKID_SRC_SEL]	= &meson_mx_sdhc_src_sel,
> +	[SDHC_CLKID_DIV]	= &meson_mx_sdhc_div,
> +	[SDHC_CLKID_MOD_CLK]	= &meson_mx_sdhc_mod_clk_en,
> +	[SDHC_CLKID_SD_CLK]	= &meson_mx_sdhc_sd_clk_en,
> +	[SDHC_CLKID_TX_CLK]	= &meson_mx_sdhc_tx_clk_en,
> +	[SDHC_CLKID_RX_CLK]	= &meson_mx_sdhc_rx_clk_en,
> +};
> +
> +#define MESON_MX_SDHC_NUM_CLKS ARRAY_SIZE(meson_mx_sdhc_clk_regmaps)
> +
> +static int meson_mx_sdhc_clkc_probe(struct platform_device *pdev)
> +{
> +	struct device *parent = pdev->dev.parent;
> +	struct clk_hw_onecell_data *onecell_data;
> +	struct clk_regmap *clk_regmap;
> +	struct regmap *regmap;
> +	int i, ret;
> +
> +	regmap = dev_get_regmap(parent, NULL);
> +	if (IS_ERR(regmap))
> +		return PTR_ERR(regmap);
> +
> +	clk_regmap = devm_kcalloc(parent, sizeof(*clk_regmap),
> +				  MESON_MX_SDHC_NUM_CLKS, GFP_KERNEL);
> +	if (!clk_regmap)
> +		return -ENOMEM;
> +
> +	onecell_data = devm_kzalloc(parent,
> +				    struct_size(onecell_data, hws,
> +						MESON_MX_SDHC_NUM_CLKS),
> +				    GFP_KERNEL);
> +	if (!onecell_data)
> +		return -ENOMEM;
> +
> +	for (i = 0; i < MESON_MX_SDHC_NUM_CLKS; i++) {
> +		memcpy(&clk_regmap[i], meson_mx_sdhc_clk_regmaps[i],
> +		       sizeof(*clk_regmap));
> +
> +		clk_regmap[i].map = regmap;
> +		onecell_data->hws[i] = &clk_regmap[i].hw;
> +
> +		ret = devm_clk_hw_register(parent, onecell_data->hws[i]);
> +		if (ret) {
> +			dev_err(parent,
> +				"Registration of SDHC clock %d failed\n", i);
> +			return ret;
> +		}
> +	}
> +
> +	onecell_data->num = MESON_MX_SDHC_NUM_CLKS;
> +
> +	return devm_of_clk_add_hw_provider(parent, of_clk_hw_onecell_get,
> +					   onecell_data);
> +}
> +
> +static const struct platform_device_id meson_mx_sdhc_clkc_ids[] = {
> +	{ "meson8-sdhc-clkc" },
> +	{ "meson8b-sdhc-clkc" },
> +	{ "meson8m2-sdhc-clkc" },
> +	{ /* sentinel */ }
> +};
> +MODULE_DEVICE_TABLE(platform, meson_mx_sdhc_clkc_ids);
> +
> +static struct platform_driver meson_mx_sdhc_clkc_driver = {
> +	.id_table	= meson_mx_sdhc_clkc_ids,
> +	.probe		= meson_mx_sdhc_clkc_probe,
> +	.driver		= {
> +		.name	= "meson-mx-sdhc-clkc",
> +	},
> +};
> +module_platform_driver(meson_mx_sdhc_clkc_driver);
> +
> +MODULE_DESCRIPTION("Amlogic Meson8/8b/8m2 SDHC clock controller driver");
> +MODULE_AUTHOR("Martin Blumenstingl <martin.blumenstingl@googlemail.com>");
> +MODULE_LICENSE("GPL v2");
Martin Blumenstingl April 27, 2020, 4:33 p.m. UTC | #2 
Hi Jerome,

thank you for looking into this!

On Mon, Apr 27, 2020 at 10:41 AM Jerome Brunet <jbrunet@baylibre.com> wrote:
[...]
> > +#include "clk-regmap.h"
> > +#include "clk-pll.h"
>
> If you need the pll clocks, it should probably appear in the Kconfig
> deps as well
this driver does not need "clk-pll.h"
good catch - thank you

> > +
> > +#define MESON_SDHC_CLKC                      0x10
> > +
> > +static const struct clk_regmap meson_mx_sdhc_src_sel = {
> > +     .data = &(struct clk_regmap_mux_data){
> > +             .offset = MESON_SDHC_CLKC,
> > +             .mask = 0x3,
> > +             .shift = 16,
> > +     },
> > +     .hw.init = &(struct clk_init_data){
> > +             .name = "sdhc_src_sel",
> > +             .ops = &clk_regmap_mux_ops,
> > +             .parent_data = (const struct clk_parent_data[]) {
> > +                     { .fw_name = "clkin0", .index = -1, },
> > +                     { .fw_name = "clkin1", .index = -1, },
> > +                     { .fw_name = "clkin2", .index = -1, },
> > +                     { .fw_name = "clkin3", .index = -1, },
>
> When fw_name is specified, setting the index is not necessary
noted, will fix this

[...]
> > +     .hw.init = &(struct clk_init_data){
> > +             .name = "sdhc_div",
> > +             .ops = &clk_regmap_divider_ops,
> > +             .parent_data = (const struct clk_parent_data[]) {
> > +                     { .name = "sdhc_src_sel", .index = -1, },
>
> Any reason for using the lagacy names and not the clk_hw pointers ?
> Same comment for the rest of the clocks
indeed, there is a reason and it took me a while to figure out
__clk_register will set hw->init = NULL;
This means: if we unregister the driver and register it again all
hw->init will be lost (as it's now NULL)
This is why I am effectively cloning (devm_kzalloc + memcpy) these
clocks which only serve as a template
Due to this I can't easily use a reference to another clk_hw

We don't have this problem in any of our other clock controller
drivers because these cannot be unloaded

[...]
> > +     .hw.init = &(struct clk_init_data){
> > +             .name = "sdhc_mod_clk_on",
> > +             .ops = &clk_regmap_gate_ops,
> > +             .parent_data = (const struct clk_parent_data[]) {
> > +                     { .name = "sdhc_div", .index = -1, },
> > +             },
> > +             .num_parents = 1,
> > +             .flags = CLK_SET_RATE_GATE,
>
> Why can't the clock change rate unless gated ? Maybe you prefer to
> change the rate in the mmc while clock is gated, but this is the
> handling of the clock by the mmc driver, not a constraint of the actual
> clock HW, isn't it ?
>
> Also, this is a gate so I suppose the rate propagates through it ?
> Can you explain why CLK_SET_RATE_PARENT is not set  ?
[...]
> Ok so apparently you only want to set the rate through the RX clock.
> You are free to call set_rate() only on this clock in the mmc driver.
> However, I don't think this should reflect as clock constraints.
I think these two belong together
looking back at this I believe that you are right:
- CLK_SET_RATE_GATE should be dropped because that's not a constraint
of the clock but of the clock consumer (MMC driver)
- CLK_SET_RATE_PARENT should be added to all clocks because rate
propagation will work for all clocks

> > +     },
> > +};
> > +
> > +static const struct clk_regmap meson_mx_sdhc_sd_clk_en = {
> > +     .data = &(struct clk_regmap_gate_data){
> > +             .offset = MESON_SDHC_CLKC,
> > +             .bit_idx = 12,
> > +     },
> > +     .hw.init = &(struct clk_init_data){
> > +             .name = "sdhc_sd_clk_on",
> > +             .ops = &clk_regmap_gate_ops,
> > +             .parent_data = (const struct clk_parent_data[]) {
> > +                     { .name = "sdhc_div", .index = -1, },
> > +             },
> > +             .num_parents = 1,
> > +             .flags = CLK_SET_RATE_PARENT | CLK_SET_RATE_GATE,
>
> ... now I lost with these flags. I'm sure there is an idea related to
> the mmc driver. Clockwise, I don't get it.
indeed, just like above I'll fix these


Martin
Jerome Brunet April 27, 2020, 4:58 p.m. UTC | #3 
On Mon 27 Apr 2020 at 18:33, Martin Blumenstingl <martin.blumenstingl@googlemail.com> wrote:

> Hi Jerome,
>
> thank you for looking into this!
>
> On Mon, Apr 27, 2020 at 10:41 AM Jerome Brunet <jbrunet@baylibre.com> wrote:
> [...]
>> > +#include "clk-regmap.h"
>> > +#include "clk-pll.h"
>>
>> If you need the pll clocks, it should probably appear in the Kconfig
>> deps as well
> this driver does not need "clk-pll.h"
> good catch - thank you
>
>> > +
>> > +#define MESON_SDHC_CLKC                      0x10
>> > +
>> > +static const struct clk_regmap meson_mx_sdhc_src_sel = {
>> > +     .data = &(struct clk_regmap_mux_data){
>> > +             .offset = MESON_SDHC_CLKC,
>> > +             .mask = 0x3,
>> > +             .shift = 16,
>> > +     },
>> > +     .hw.init = &(struct clk_init_data){
>> > +             .name = "sdhc_src_sel",
>> > +             .ops = &clk_regmap_mux_ops,
>> > +             .parent_data = (const struct clk_parent_data[]) {
>> > +                     { .fw_name = "clkin0", .index = -1, },
>> > +                     { .fw_name = "clkin1", .index = -1, },
>> > +                     { .fw_name = "clkin2", .index = -1, },
>> > +                     { .fw_name = "clkin3", .index = -1, },
>>
>> When fw_name is specified, setting the index is not necessary
> noted, will fix this
>
> [...]
>> > +     .hw.init = &(struct clk_init_data){
>> > +             .name = "sdhc_div",
>> > +             .ops = &clk_regmap_divider_ops,
>> > +             .parent_data = (const struct clk_parent_data[]) {
>> > +                     { .name = "sdhc_src_sel", .index = -1, },
>>
>> Any reason for using the lagacy names and not the clk_hw pointers ?
>> Same comment for the rest of the clocks
> indeed, there is a reason and it took me a while to figure out
> __clk_register will set hw->init = NULL;
> This means: if we unregister the driver and register it again all
> hw->init will be lost (as it's now NULL)

I think Stephen recently added the reset to NULL and it might be an
unintended consequence. AFAICT, you should be able to use hw pointer
here even if the driver unloads.
Please report it to linux-clk


> This is why I am effectively cloning (devm_kzalloc + memcpy) these
> clocks which only serve as a template
> Due to this I can't easily use a reference to another clk_hw
>
> We don't have this problem in any of our other clock controller
> drivers because these cannot be unloaded
>
> [...]
>> > +     .hw.init = &(struct clk_init_data){
>> > +             .name = "sdhc_mod_clk_on",
>> > +             .ops = &clk_regmap_gate_ops,
>> > +             .parent_data = (const struct clk_parent_data[]) {
>> > +                     { .name = "sdhc_div", .index = -1, },
>> > +             },
>> > +             .num_parents = 1,
>> > +             .flags = CLK_SET_RATE_GATE,
>>
>> Why can't the clock change rate unless gated ? Maybe you prefer to
>> change the rate in the mmc while clock is gated, but this is the
>> handling of the clock by the mmc driver, not a constraint of the actual
>> clock HW, isn't it ?
>>
>> Also, this is a gate so I suppose the rate propagates through it ?
>> Can you explain why CLK_SET_RATE_PARENT is not set  ?
> [...]
>> Ok so apparently you only want to set the rate through the RX clock.
>> You are free to call set_rate() only on this clock in the mmc driver.
>> However, I don't think this should reflect as clock constraints.
> I think these two belong together
> looking back at this I believe that you are right:
> - CLK_SET_RATE_GATE should be dropped because that's not a constraint
> of the clock but of the clock consumer (MMC driver)
> - CLK_SET_RATE_PARENT should be added to all clocks because rate
> propagation will work for all clocks
>
>> > +     },
>> > +};
>> > +
>> > +static const struct clk_regmap meson_mx_sdhc_sd_clk_en = {
>> > +     .data = &(struct clk_regmap_gate_data){
>> > +             .offset = MESON_SDHC_CLKC,
>> > +             .bit_idx = 12,
>> > +     },
>> > +     .hw.init = &(struct clk_init_data){
>> > +             .name = "sdhc_sd_clk_on",
>> > +             .ops = &clk_regmap_gate_ops,
>> > +             .parent_data = (const struct clk_parent_data[]) {
>> > +                     { .name = "sdhc_div", .index = -1, },
>> > +             },
>> > +             .num_parents = 1,
>> > +             .flags = CLK_SET_RATE_PARENT | CLK_SET_RATE_GATE,
>>
>> ... now I lost with these flags. I'm sure there is an idea related to
>> the mmc driver. Clockwise, I don't get it.
> indeed, just like above I'll fix these
>
>
> Martin
diff mbox series

Patch

diff --git a/drivers/clk/meson/Kconfig b/drivers/clk/meson/Kconfig
index dabeb435d067..8769335d2d46 100644
--- a/drivers/clk/meson/Kconfig
+++ b/drivers/clk/meson/Kconfig
@@ -53,6 +53,15 @@  config COMMON_CLK_MESON8B
 	  S805 (Meson8b) and S812 (Meson8m2) devices. Say Y if you
 	  want peripherals and CPU frequency scaling to work.
 
+config COMMON_CLK_MESON_MX_SDHC
+	tristate "Meson MX SDHC MMC Clock Controller Driver"
+	depends on ARCH_MESON
+	select COMMON_CLK_MESON_REGMAP
+	help
+	  Support for the SDHC clock controller on Amlogic Meson8/8b/8m2 SoCs
+	  devices. Say Y or M if you want to use the SDHC MMC controller.
+	  Otherwise say N.
+
 config COMMON_CLK_GXBB
 	bool
 	depends on ARCH_MESON
diff --git a/drivers/clk/meson/Makefile b/drivers/clk/meson/Makefile
index 6eca2a406ee3..b71c7ae78dbd 100644
--- a/drivers/clk/meson/Makefile
+++ b/drivers/clk/meson/Makefile
@@ -19,3 +19,4 @@  obj-$(CONFIG_COMMON_CLK_AXG_AUDIO) += axg-audio.o
 obj-$(CONFIG_COMMON_CLK_GXBB) += gxbb.o gxbb-aoclk.o
 obj-$(CONFIG_COMMON_CLK_G12A) += g12a.o g12a-aoclk.o
 obj-$(CONFIG_COMMON_CLK_MESON8B) += meson8b.o meson8-ddr.o
+obj-$(CONFIG_COMMON_CLK_MESON_MX_SDHC) += meson-mx-sdhc.o
diff --git a/drivers/clk/meson/meson-mx-sdhc.c b/drivers/clk/meson/meson-mx-sdhc.c
new file mode 100644
index 000000000000..b98a35d99f65
--- /dev/null
+++ b/drivers/clk/meson/meson-mx-sdhc.c
@@ -0,0 +1,212 @@ 
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Amlogic Meson SDHC clock controller
+ *
+ * Copyright (C) 2019 Martin Blumenstingl <martin.blumenstingl@googlemail.com>
+ */
+
+#include <dt-bindings/clock/meson-mx-sdhc-clkc.h>
+
+#include <linux/clk-provider.h>
+#include <linux/device.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+
+#include "clk-regmap.h"
+#include "clk-pll.h"
+
+#define MESON_SDHC_CLKC			0x10
+
+static const struct clk_regmap meson_mx_sdhc_src_sel = {
+	.data = &(struct clk_regmap_mux_data){
+		.offset = MESON_SDHC_CLKC,
+		.mask = 0x3,
+		.shift = 16,
+	},
+	.hw.init = &(struct clk_init_data){
+		.name = "sdhc_src_sel",
+		.ops = &clk_regmap_mux_ops,
+		.parent_data = (const struct clk_parent_data[]) {
+			{ .fw_name = "clkin0", .index = -1, },
+			{ .fw_name = "clkin1", .index = -1, },
+			{ .fw_name = "clkin2", .index = -1, },
+			{ .fw_name = "clkin3", .index = -1, },
+		},
+		.num_parents = 4,
+	},
+};
+
+static const struct clk_div_table meson_mx_sdhc_div_table[] = {
+	{ .div = 6, .val = 5, },
+	{ .div = 8, .val = 7, },
+	{ .div = 9, .val = 8, },
+	{ .div = 10, .val = 9, },
+	{ .div = 12, .val = 11, },
+	{ .div = 16, .val = 15, },
+	{ .div = 18, .val = 17, },
+	{ .div = 34, .val = 33, },
+	{ .div = 142, .val = 141, },
+	{ .div = 850, .val = 849, },
+	{ .div = 2126, .val = 2125, },
+	{ .div = 4096, .val = 4095, },
+	{ /* sentinel */ }
+};
+
+static const struct clk_regmap meson_mx_sdhc_div = {
+	.data = &(struct clk_regmap_div_data){
+		.offset = MESON_SDHC_CLKC,
+		.shift = 0,
+		.width = 12,
+		.table = meson_mx_sdhc_div_table,
+	},
+	.hw.init = &(struct clk_init_data){
+		.name = "sdhc_div",
+		.ops = &clk_regmap_divider_ops,
+		.parent_data = (const struct clk_parent_data[]) {
+			{ .name = "sdhc_src_sel", .index = -1, },
+		},
+		.num_parents = 1,
+		.flags = CLK_SET_RATE_PARENT,
+	},
+};
+
+static const struct clk_regmap meson_mx_sdhc_mod_clk_en = {
+	.data = &(struct clk_regmap_gate_data){
+		.offset = MESON_SDHC_CLKC,
+		.bit_idx = 15,
+	},
+	.hw.init = &(struct clk_init_data){
+		.name = "sdhc_mod_clk_on",
+		.ops = &clk_regmap_gate_ops,
+		.parent_data = (const struct clk_parent_data[]) {
+			{ .name = "sdhc_div", .index = -1, },
+		},
+		.num_parents = 1,
+		.flags = CLK_SET_RATE_GATE,
+	},
+};
+
+static const struct clk_regmap meson_mx_sdhc_tx_clk_en = {
+	.data = &(struct clk_regmap_gate_data){
+		.offset = MESON_SDHC_CLKC,
+		.bit_idx = 14,
+	},
+	.hw.init = &(struct clk_init_data){
+		.name = "sdhc_tx_clk_on",
+		.ops = &clk_regmap_gate_ops,
+		.parent_data = (const struct clk_parent_data[]) {
+			{ .name = "sdhc_div", .index = -1, },
+		},
+		.num_parents = 1,
+		.flags = CLK_SET_RATE_GATE,
+	},
+};
+
+static const struct clk_regmap meson_mx_sdhc_rx_clk_en = {
+	.data = &(struct clk_regmap_gate_data){
+		.offset = MESON_SDHC_CLKC,
+		.bit_idx = 13,
+	},
+	.hw.init = &(struct clk_init_data){
+		.name = "sdhc_rx_clk_on",
+		.ops = &clk_regmap_gate_ops,
+		.parent_data = (const struct clk_parent_data[]) {
+			{ .name = "sdhc_div", .index = -1, },
+		},
+		.num_parents = 1,
+		.flags = CLK_SET_RATE_PARENT | CLK_SET_RATE_GATE,
+	},
+};
+
+static const struct clk_regmap meson_mx_sdhc_sd_clk_en = {
+	.data = &(struct clk_regmap_gate_data){
+		.offset = MESON_SDHC_CLKC,
+		.bit_idx = 12,
+	},
+	.hw.init = &(struct clk_init_data){
+		.name = "sdhc_sd_clk_on",
+		.ops = &clk_regmap_gate_ops,
+		.parent_data = (const struct clk_parent_data[]) {
+			{ .name = "sdhc_div", .index = -1, },
+		},
+		.num_parents = 1,
+		.flags = CLK_SET_RATE_PARENT | CLK_SET_RATE_GATE,
+	},
+};
+
+static const struct clk_regmap *meson_mx_sdhc_clk_regmaps[] = {
+	[SDHC_CLKID_SRC_SEL]	= &meson_mx_sdhc_src_sel,
+	[SDHC_CLKID_DIV]	= &meson_mx_sdhc_div,
+	[SDHC_CLKID_MOD_CLK]	= &meson_mx_sdhc_mod_clk_en,
+	[SDHC_CLKID_SD_CLK]	= &meson_mx_sdhc_sd_clk_en,
+	[SDHC_CLKID_TX_CLK]	= &meson_mx_sdhc_tx_clk_en,
+	[SDHC_CLKID_RX_CLK]	= &meson_mx_sdhc_rx_clk_en,
+};
+
+#define MESON_MX_SDHC_NUM_CLKS ARRAY_SIZE(meson_mx_sdhc_clk_regmaps)
+
+static int meson_mx_sdhc_clkc_probe(struct platform_device *pdev)
+{
+	struct device *parent = pdev->dev.parent;
+	struct clk_hw_onecell_data *onecell_data;
+	struct clk_regmap *clk_regmap;
+	struct regmap *regmap;
+	int i, ret;
+
+	regmap = dev_get_regmap(parent, NULL);
+	if (IS_ERR(regmap))
+		return PTR_ERR(regmap);
+
+	clk_regmap = devm_kcalloc(parent, sizeof(*clk_regmap),
+				  MESON_MX_SDHC_NUM_CLKS, GFP_KERNEL);
+	if (!clk_regmap)
+		return -ENOMEM;
+
+	onecell_data = devm_kzalloc(parent,
+				    struct_size(onecell_data, hws,
+						MESON_MX_SDHC_NUM_CLKS),
+				    GFP_KERNEL);
+	if (!onecell_data)
+		return -ENOMEM;
+
+	for (i = 0; i < MESON_MX_SDHC_NUM_CLKS; i++) {
+		memcpy(&clk_regmap[i], meson_mx_sdhc_clk_regmaps[i],
+		       sizeof(*clk_regmap));
+
+		clk_regmap[i].map = regmap;
+		onecell_data->hws[i] = &clk_regmap[i].hw;
+
+		ret = devm_clk_hw_register(parent, onecell_data->hws[i]);
+		if (ret) {
+			dev_err(parent,
+				"Registration of SDHC clock %d failed\n", i);
+			return ret;
+		}
+	}
+
+	onecell_data->num = MESON_MX_SDHC_NUM_CLKS;
+
+	return devm_of_clk_add_hw_provider(parent, of_clk_hw_onecell_get,
+					   onecell_data);
+}
+
+static const struct platform_device_id meson_mx_sdhc_clkc_ids[] = {
+	{ "meson8-sdhc-clkc" },
+	{ "meson8b-sdhc-clkc" },
+	{ "meson8m2-sdhc-clkc" },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(platform, meson_mx_sdhc_clkc_ids);
+
+static struct platform_driver meson_mx_sdhc_clkc_driver = {
+	.id_table	= meson_mx_sdhc_clkc_ids,
+	.probe		= meson_mx_sdhc_clkc_probe,
+	.driver		= {
+		.name	= "meson-mx-sdhc-clkc",
+	},
+};
+module_platform_driver(meson_mx_sdhc_clkc_driver);
+
+MODULE_DESCRIPTION("Amlogic Meson8/8b/8m2 SDHC clock controller driver");
+MODULE_AUTHOR("Martin Blumenstingl <martin.blumenstingl@googlemail.com>");
+MODULE_LICENSE("GPL v2");