diff mbox series

[v2,2/5] clk: meson: add a driver for the Meson8/8b/8m2 DDR clock controller

Message ID 20191027162328.1177402-3-martin.blumenstingl@googlemail.com (mailing list archive)
State Superseded
Delegated to: Neil Armstrong
Headers show
Series add the DDR clock controller on Meson8 and Meson8b | expand

Commit Message

Martin Blumenstingl Oct. 27, 2019, 4:23 p.m. UTC 
The Meson8/Meson8b/Meson8m2 SoCs embed a DDR clock controller in the
MMCBUS registers. There is no public documentation, but the u-boot GPL
sources from the Amlogic BSP show that the DDR clock controller is
identical on all three SoCs:
  #define CFG_DDR_CLK 792
  #define CFG_PLL_M (((CFG_DDR_CLK/12)*12)/24)
  #define CFG_PLL_N 1
  #define CFG_PLL_OD 1

  // from set_ddr_clock:
  t_ddr_pll_cntl= (CFG_PLL_OD << 16)|(CFG_PLL_N<<9)|(CFG_PLL_M<<0)
  writel(timing_reg->t_ddr_pll_cntl|(1<<29),AM_DDR_PLL_CNTL);
  writel(readl(AM_DDR_PLL_CNTL) & (~(1<<29)),AM_DDR_PLL_CNTL);

  // from hx_ddr_power_down_enter: shut down DDR PLL
  writel(readl(AM_DDR_PLL_CNTL)|(1<<30),AM_DDR_PLL_CNTL);

  do { ... } while((readl(AM_DDR_PLL_CNTL)&(1<<31))==0)

This translates to:
- AM_DDR_PLL_CNTL[29] is the reset bit
- AM_DDR_PLL_CNTL[30] is the enable bit
- AM_DDR_PLL_CNTL[31] is the lock bit
- AM_DDR_PLL_CNTL[8:0] is the m value (assuming the width is 9 bits
  based on the start of the n value)
- AM_DDR_PLL_CNTL[13:9] is the n value (assuming the width is 5 bits
  based on the start of the od)
- AM_DDR_PLL_CNTL[17:16] is the od (assuming the width is 2 bits based
  on other PLLs on this SoC)

Add a driver for this PLL setup because it's used as one of the inputs
of the audio clocks. There may be more clocks inside that clock
controller - those can be added in subsequent patches.

Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
---
 drivers/clk/meson/Makefile     |   2 +-
 drivers/clk/meson/meson8-ddr.c | 152 +++++++++++++++++++++++++++++++++
 2 files changed, 153 insertions(+), 1 deletion(-)
 create mode 100644 drivers/clk/meson/meson8-ddr.c

Comments

Stephen Boyd Nov. 8, 2019, 10:16 p.m. UTC | #1 
Quoting Martin Blumenstingl (2019-10-27 09:23:25)
> diff --git a/drivers/clk/meson/meson8-ddr.c b/drivers/clk/meson/meson8-ddr.c
> new file mode 100644
> index 000000000000..4aefcc5bdaae
> --- /dev/null
> +++ b/drivers/clk/meson/meson8-ddr.c
> @@ -0,0 +1,152 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +/*
> + * Amlogic Meson8 DDR clock controller
> + *
> + * Copyright (C) 2019 Martin Blumenstingl <martin.blumenstingl@googlemail.com>
> + */
> +
> +#include <dt-bindings/clock/meson8-ddr-clkc.h>
> +
> +#include <linux/platform_device.h>
> +#include <linux/of_device.h>
> +#include <linux/slab.h>

Please include clk-provider.h as this is a clk provider driver.

> +
> +#include "clk-regmap.h"
> +#include "clk-pll.h"
> +
> +#define AM_DDR_PLL_CNTL                        0x00
> +#define AM_DDR_PLL_CNTL1               0x04
> +#define AM_DDR_PLL_CNTL2               0x08
> +#define AM_DDR_PLL_CNTL3               0x0c
> +#define AM_DDR_PLL_CNTL4               0x10
> +#define AM_DDR_PLL_STS                 0x14
> +#define DDR_CLK_CNTL                   0x18
> +#define DDR_CLK_STS                    0x1c
> +
> +static struct clk_regmap meson8_ddr_pll_dco = {
> +       .data = &(struct meson_clk_pll_data){
> +               .en = {
> +                       .reg_off = AM_DDR_PLL_CNTL,
> +                       .shift   = 30,
> +                       .width   = 1,
> +               },
> +               .m = {
> +                       .reg_off = AM_DDR_PLL_CNTL,
> +                       .shift   = 0,
> +                       .width   = 9,
> +               },
> +               .n = {
> +                       .reg_off = AM_DDR_PLL_CNTL,
> +                       .shift   = 9,
> +                       .width   = 5,
> +               },
> +               .l = {
> +                       .reg_off = AM_DDR_PLL_CNTL,
> +                       .shift   = 31,
> +                       .width   = 1,
> +               },
> +               .rst = {
> +                       .reg_off = AM_DDR_PLL_CNTL,
> +                       .shift   = 29,
> +                       .width   = 1,
> +               },
> +       },
> +       .hw.init = &(struct clk_init_data){
> +               .name = "ddr_pll_dco",
> +               .ops = &meson_clk_pll_ro_ops,
> +               .parent_data = &(const struct clk_parent_data) {
> +                       .fw_name = "xtal",
> +               },
> +               .num_parents = 1,
> +       },
> +};
> +
> +static struct clk_regmap meson8_ddr_pll = {
> +       .data = &(struct clk_regmap_div_data){
> +               .offset = AM_DDR_PLL_CNTL,
> +               .shift = 16,
> +               .width = 2,
> +               .flags = CLK_DIVIDER_POWER_OF_TWO,
> +       },
> +       .hw.init = &(struct clk_init_data){
> +               .name = "ddr_pll",
> +               .ops = &clk_regmap_divider_ro_ops,
> +               .parent_hws = (const struct clk_hw *[]) {
> +                       &meson8_ddr_pll_dco.hw
> +               },
> +               .num_parents = 1,
> +       },
> +};
> +
> +static struct clk_hw_onecell_data meson8_ddr_clk_hw_onecell_data = {
> +       .hws = {
> +               [DDR_CLKID_DDR_PLL_DCO]         = &meson8_ddr_pll_dco.hw,
> +               [DDR_CLKID_DDR_PLL]             = &meson8_ddr_pll.hw,
> +       },
> +       .num = 2,
> +};
> +
> +static struct clk_regmap *const meson8_ddr_clk_regmaps[] = {
> +       &meson8_ddr_pll_dco,
> +       &meson8_ddr_pll,
> +};
> +
> +static const struct regmap_config meson8_ddr_clkc_regmap_config = {
> +       .reg_bits = 8,
> +       .val_bits = 32,
> +       .reg_stride = 4,
> +       .max_register = DDR_CLK_STS,
> +};
> +
> +static int meson8_ddr_clkc_probe(struct platform_device *pdev)
> +{
> +       struct regmap *regmap;
> +       struct resource *res;
> +       void __iomem *base;
> +       struct clk_hw *hw;
> +       int ret, i;
> +
> +       res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> +       base = devm_ioremap_resource(&pdev->dev, res);

We have a new function to combine the above two lines. Please use it so
the janitors avoid this file.

> +       if (IS_ERR(base))
> +               return PTR_ERR(base);
> +
> +       regmap = devm_regmap_init_mmio(&pdev->dev, base,
> +                                      &meson8_ddr_clkc_regmap_config);
> +       if (IS_ERR(regmap))
> +               return PTR_ERR(regmap);
> +
> +       /* Populate regmap */
> +       for (i = 0; i < ARRAY_SIZE(meson8_ddr_clk_regmaps); i++)
> +               meson8_ddr_clk_regmaps[i]->map = regmap;
> +
> +       /* Register all clks */
> +       for (i = 0; i < meson8_ddr_clk_hw_onecell_data.num; i++) {
> +               hw = meson8_ddr_clk_hw_onecell_data.hws[i];
> +
> +               ret = devm_clk_hw_register(&pdev->dev, hw);
> +               if (ret) {
> +                       dev_err(&pdev->dev, "Clock registration failed\n");
> +                       return ret;
> +               }
> +       }
> +
> +       return devm_of_clk_add_hw_provider(&pdev->dev, of_clk_hw_onecell_get,
> +                                          &meson8_ddr_clk_hw_onecell_data);
> +}
> +
> +static const struct of_device_id meson8_ddr_clkc_match_table[] = {
> +       { .compatible = "amlogic,meson8-ddr-clkc" },
> +       { .compatible = "amlogic,meson8b-ddr-clkc" },
> +       { /* sentinel */ },

Super nitpick, drop the comma above so that nothing can follow this.

> +};
> +
> +static struct platform_driver meson8_ddr_clkc_driver = {
> +       .probe          = meson8_ddr_clkc_probe,
> +       .driver         = {
> +               .name   = "meson8-ddr-clkc",
> +               .of_match_table = meson8_ddr_clkc_match_table,
> +       },
> +};
> +
> +builtin_platform_driver(meson8_ddr_clkc_driver);
> -- 
> 2.23.0
>
Jerome Brunet Nov. 12, 2019, 5:20 p.m. UTC | #2 
>> +static const struct of_device_id meson8_ddr_clkc_match_table[] = {
>> +       { .compatible = "amlogic,meson8-ddr-clkc" },
>> +       { .compatible = "amlogic,meson8b-ddr-clkc" },
>> +       { /* sentinel */ },
>
> Super nitpick, drop the comma above so that nothing can follow this.

I don't think it is worth reposting the series Martin.
If it is ok with you, I'll just apply it with Stephen comments

In the future, I would prefer if you could separate the series for clock
(intended for Neil and myself) and the DT one (intended for Kevin)

Thx

>
>> +};
>> +
>> +static struct platform_driver meson8_ddr_clkc_driver = {
>> +       .probe          = meson8_ddr_clkc_probe,
>> +       .driver         = {
>> +               .name   = "meson8-ddr-clkc",
>> +               .of_match_table = meson8_ddr_clkc_match_table,
>> +       },
>> +};
>> +
>> +builtin_platform_driver(meson8_ddr_clkc_driver);
>> -- 
>> 2.23.0
>>
Martin Blumenstingl Nov. 12, 2019, 8:52 p.m. UTC | #3 
Hi Jerome,

On Tue, Nov 12, 2019 at 6:20 PM Jerome Brunet <jbrunet@baylibre.com> wrote:
>
>
> >> +static const struct of_device_id meson8_ddr_clkc_match_table[] = {
> >> +       { .compatible = "amlogic,meson8-ddr-clkc" },
> >> +       { .compatible = "amlogic,meson8b-ddr-clkc" },
> >> +       { /* sentinel */ },
> >
> > Super nitpick, drop the comma above so that nothing can follow this.
>
> I don't think it is worth reposting the series Martin.
> If it is ok with you, I'll just apply it with Stephen comments
I am more than happy with this.
just to confirm, you would address all three comments from Stephen:
- including clk-provider.h
- use devm_platform_ioremap_resource
- trailing comma after the sentinel

> In the future, I would prefer if you could separate the series for clock
> (intended for Neil and myself) and the DT one (intended for Kevin)
sorry, we discussed this previously but I completely forgot about it
when I re-sent this series
I'll be more careful next time



Martin
Martin Blumenstingl Nov. 16, 2019, 4:52 p.m. UTC | #4 
Hi Jerome,

On Tue, Nov 12, 2019 at 9:52 PM Martin Blumenstingl
<martin.blumenstingl@googlemail.com> wrote:
>
> Hi Jerome,
>
> On Tue, Nov 12, 2019 at 6:20 PM Jerome Brunet <jbrunet@baylibre.com> wrote:
> >
> >
> > >> +static const struct of_device_id meson8_ddr_clkc_match_table[] = {
> > >> +       { .compatible = "amlogic,meson8-ddr-clkc" },
> > >> +       { .compatible = "amlogic,meson8b-ddr-clkc" },
> > >> +       { /* sentinel */ },
> > >
> > > Super nitpick, drop the comma above so that nothing can follow this.
> >
> > I don't think it is worth reposting the series Martin.
> > If it is ok with you, I'll just apply it with Stephen comments
> I am more than happy with this.
> just to confirm, you would address all three comments from Stephen:
> - including clk-provider.h
> - use devm_platform_ioremap_resource
> - trailing comma after the sentinel
I'll have to re-send this series anyway, so I'll fix these myself.
still thank you for the offer :)

I think it's better to move patch #3 from this series to the "XTAL
from OF" series, which means I have to re-send


Martin
diff mbox series

Patch

diff --git a/drivers/clk/meson/Makefile b/drivers/clk/meson/Makefile
index 3939f218587a..6eca2a406ee3 100644
--- a/drivers/clk/meson/Makefile
+++ b/drivers/clk/meson/Makefile
@@ -18,4 +18,4 @@  obj-$(CONFIG_COMMON_CLK_AXG) += axg.o axg-aoclk.o
 obj-$(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-$(CONFIG_COMMON_CLK_MESON8B) += meson8b.o
+obj-$(CONFIG_COMMON_CLK_MESON8B) += meson8b.o meson8-ddr.o
diff --git a/drivers/clk/meson/meson8-ddr.c b/drivers/clk/meson/meson8-ddr.c
new file mode 100644
index 000000000000..4aefcc5bdaae
--- /dev/null
+++ b/drivers/clk/meson/meson8-ddr.c
@@ -0,0 +1,152 @@ 
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Amlogic Meson8 DDR clock controller
+ *
+ * Copyright (C) 2019 Martin Blumenstingl <martin.blumenstingl@googlemail.com>
+ */
+
+#include <dt-bindings/clock/meson8-ddr-clkc.h>
+
+#include <linux/platform_device.h>
+#include <linux/of_device.h>
+#include <linux/slab.h>
+
+#include "clk-regmap.h"
+#include "clk-pll.h"
+
+#define AM_DDR_PLL_CNTL			0x00
+#define AM_DDR_PLL_CNTL1		0x04
+#define AM_DDR_PLL_CNTL2		0x08
+#define AM_DDR_PLL_CNTL3		0x0c
+#define AM_DDR_PLL_CNTL4		0x10
+#define AM_DDR_PLL_STS			0x14
+#define DDR_CLK_CNTL			0x18
+#define DDR_CLK_STS			0x1c
+
+static struct clk_regmap meson8_ddr_pll_dco = {
+	.data = &(struct meson_clk_pll_data){
+		.en = {
+			.reg_off = AM_DDR_PLL_CNTL,
+			.shift   = 30,
+			.width   = 1,
+		},
+		.m = {
+			.reg_off = AM_DDR_PLL_CNTL,
+			.shift   = 0,
+			.width   = 9,
+		},
+		.n = {
+			.reg_off = AM_DDR_PLL_CNTL,
+			.shift   = 9,
+			.width   = 5,
+		},
+		.l = {
+			.reg_off = AM_DDR_PLL_CNTL,
+			.shift   = 31,
+			.width   = 1,
+		},
+		.rst = {
+			.reg_off = AM_DDR_PLL_CNTL,
+			.shift   = 29,
+			.width   = 1,
+		},
+	},
+	.hw.init = &(struct clk_init_data){
+		.name = "ddr_pll_dco",
+		.ops = &meson_clk_pll_ro_ops,
+		.parent_data = &(const struct clk_parent_data) {
+			.fw_name = "xtal",
+		},
+		.num_parents = 1,
+	},
+};
+
+static struct clk_regmap meson8_ddr_pll = {
+	.data = &(struct clk_regmap_div_data){
+		.offset = AM_DDR_PLL_CNTL,
+		.shift = 16,
+		.width = 2,
+		.flags = CLK_DIVIDER_POWER_OF_TWO,
+	},
+	.hw.init = &(struct clk_init_data){
+		.name = "ddr_pll",
+		.ops = &clk_regmap_divider_ro_ops,
+		.parent_hws = (const struct clk_hw *[]) {
+			&meson8_ddr_pll_dco.hw
+		},
+		.num_parents = 1,
+	},
+};
+
+static struct clk_hw_onecell_data meson8_ddr_clk_hw_onecell_data = {
+	.hws = {
+		[DDR_CLKID_DDR_PLL_DCO]		= &meson8_ddr_pll_dco.hw,
+		[DDR_CLKID_DDR_PLL]		= &meson8_ddr_pll.hw,
+	},
+	.num = 2,
+};
+
+static struct clk_regmap *const meson8_ddr_clk_regmaps[] = {
+	&meson8_ddr_pll_dco,
+	&meson8_ddr_pll,
+};
+
+static const struct regmap_config meson8_ddr_clkc_regmap_config = {
+	.reg_bits = 8,
+	.val_bits = 32,
+	.reg_stride = 4,
+	.max_register = DDR_CLK_STS,
+};
+
+static int meson8_ddr_clkc_probe(struct platform_device *pdev)
+{
+	struct regmap *regmap;
+	struct resource *res;
+	void __iomem *base;
+	struct clk_hw *hw;
+	int ret, i;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	base = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(base))
+		return PTR_ERR(base);
+
+	regmap = devm_regmap_init_mmio(&pdev->dev, base,
+				       &meson8_ddr_clkc_regmap_config);
+	if (IS_ERR(regmap))
+		return PTR_ERR(regmap);
+
+	/* Populate regmap */
+	for (i = 0; i < ARRAY_SIZE(meson8_ddr_clk_regmaps); i++)
+		meson8_ddr_clk_regmaps[i]->map = regmap;
+
+	/* Register all clks */
+	for (i = 0; i < meson8_ddr_clk_hw_onecell_data.num; i++) {
+		hw = meson8_ddr_clk_hw_onecell_data.hws[i];
+
+		ret = devm_clk_hw_register(&pdev->dev, hw);
+		if (ret) {
+			dev_err(&pdev->dev, "Clock registration failed\n");
+			return ret;
+		}
+	}
+
+	return devm_of_clk_add_hw_provider(&pdev->dev, of_clk_hw_onecell_get,
+					   &meson8_ddr_clk_hw_onecell_data);
+}
+
+static const struct of_device_id meson8_ddr_clkc_match_table[] = {
+	{ .compatible = "amlogic,meson8-ddr-clkc" },
+	{ .compatible = "amlogic,meson8b-ddr-clkc" },
+	{ /* sentinel */ },
+};
+
+static struct platform_driver meson8_ddr_clkc_driver = {
+	.probe		= meson8_ddr_clkc_probe,
+	.driver		= {
+		.name	= "meson8-ddr-clkc",
+		.of_match_table = meson8_ddr_clkc_match_table,
+	},
+};
+
+builtin_platform_driver(meson8_ddr_clkc_driver);