[PATCH 0/2] Add a regmap to Allwinner R40 CCU to export GMAC register

[PATCH 0/2] Add a regmap to Allwinner R40 CCU to export GMAC register

[Icenowy Zheng]

In the CCU of the Allwinner R40 SoC, there's a GMAC configuration register,
which is intended to be accessed by the dwmac-sun8i driver. On SoCs already
supported by the driver the register is placed in the syscon rather than
the CCU.

As CCU is a critical part of the SoC, so write to it should be strictly
limited. A regmap with restricted write permission is created by the R40
CCU driver, and can be get with dev_get_regmap. In order to tie the regmap
to the CCU device, the R40 CCU is now a platform driver, so a platform
device is created for it (and then tied with the regmap).

The first patch does the conversion of the driver to a platform driver,
and the second patch adds the regmap.

Icenowy Zheng (2):
  clk: sunxi-ng: r40: rewrite init code to a platform driver
  clk: sunxi-ng: r40: export a regmap to access the GMAC register

 drivers/clk/sunxi-ng/ccu-sun8i-r40.c | 69 ++++++++++++++++++++++++++++++------
 1 file changed, 59 insertions(+), 10 deletions(-)

-- 
2.13.6

[PATCH 1/2] clk: sunxi-ng: r40: rewrite init code to a platform driver

[Icenowy Zheng]

As we need to register a regmap on the R40 CCU, there needs to be a
device structure bound to the CCU device node.

Rewrite the R40 CCU driver initial code to make it a proper platform
driver, thus we will have a platform device bound to it.

Signed-off-by: Icenowy Zheng <icenowy@aosc.io>
---
 drivers/clk/sunxi-ng/ccu-sun8i-r40.c | 37 ++++++++++++++++++++++++++----------
 1 file changed, 27 insertions(+), 10 deletions(-)

diff --git a/drivers/clk/sunxi-ng/ccu-sun8i-r40.c b/drivers/clk/sunxi-ng/ccu-sun8i-r40.c
index 933f2e68f42a..bb94e2c44e86 100644
--- a/drivers/clk/sunxi-ng/ccu-sun8i-r40.c
+++ b/drivers/clk/sunxi-ng/ccu-sun8i-r40.c
@@ -12,6 +12,7 @@
  */
 
 #include <linux/clk-provider.h>
+#include <linux/platform_device.h>
 #include <linux/of_address.h>
 
 #include "ccu_common.h"
@@ -1250,17 +1251,17 @@ static struct ccu_mux_nb sun8i_r40_cpu_nb = {
 	.bypass_index	= 1, /* index of 24 MHz oscillator */
 };
 
-static void __init sun8i_r40_ccu_setup(struct device_node *node)
+static int sun8i_r40_ccu_probe(struct platform_device *pdev)
 {
+	struct resource *res;
 	void __iomem *reg;
 	u32 val;
+	int ret;
 
-	reg = of_io_request_and_map(node, 0, of_node_full_name(node));
-	if (IS_ERR(reg)) {
-		pr_err("%s: Could not map the clock registers\n",
-		       of_node_full_name(node));
-		return;
-	}
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	reg = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(reg))
+		return PTR_ERR(reg);
 
 	/* Force the PLL-Audio-1x divider to 4 */
 	val = readl(reg + SUN8I_R40_PLL_AUDIO_REG);
@@ -1277,7 +1278,9 @@ static void __init sun8i_r40_ccu_setup(struct device_node *node)
 	val &= ~GENMASK(25, 20);
 	writel(val, reg + SUN8I_R40_USB_CLK_REG);
 
-	sunxi_ccu_probe(node, reg, &sun8i_r40_ccu_desc);
+	ret = sunxi_ccu_probe(pdev->dev.of_node, reg, &sun8i_r40_ccu_desc);
+	if (ret)
+		return ret;
 
 	/* Gate then ungate PLL CPU after any rate changes */
 	ccu_pll_notifier_register(&sun8i_r40_pll_cpu_nb);
@@ -1285,6 +1288,20 @@ static void __init sun8i_r40_ccu_setup(struct device_node *node)
 	/* Reparent CPU during PLL CPU rate changes */
 	ccu_mux_notifier_register(pll_cpu_clk.common.hw.clk,
 				  &sun8i_r40_cpu_nb);
+
+	return 0;
 }
-CLK_OF_DECLARE(sun8i_r40_ccu, "allwinner,sun8i-r40-ccu",
-	       sun8i_r40_ccu_setup);
+
+static const struct of_device_id sun8i_r40_ccu_ids[] = {
+	{ .compatible = "allwinner,sun8i-r40-ccu" },
+	{ }
+};
+
+static struct platform_driver sun8i_r40_ccu_driver = {
+	.probe	= sun8i_r40_ccu_probe,
+	.driver	= {
+		.name	= "sun8i-r40-ccu",
+		.of_match_table	= sun8i_r40_ccu_ids,
+	},
+};
+builtin_platform_driver(sun8i_r40_ccu_driver);
-- 
2.13.6

[PATCH 2/2] clk: sunxi-ng: r40: export a regmap to access the GMAC register

[Icenowy Zheng]

There's a GMAC configuration register, which exists on A64/A83T/H3/H5 in
the syscon part, in the CCU of R40 SoC.

Export a regmap of the CCU.

Read access is not restricted to all registers, but only the GMAC
register is allowed to be written.

Signed-off-by: Icenowy Zheng <icenowy@aosc.io>
---
 drivers/clk/sunxi-ng/ccu-sun8i-r40.c | 32 ++++++++++++++++++++++++++++++++
 1 file changed, 32 insertions(+)

diff --git a/drivers/clk/sunxi-ng/ccu-sun8i-r40.c b/drivers/clk/sunxi-ng/ccu-sun8i-r40.c
index bb94e2c44e86..df752bf77ff1 100644
--- a/drivers/clk/sunxi-ng/ccu-sun8i-r40.c
+++ b/drivers/clk/sunxi-ng/ccu-sun8i-r40.c
@@ -14,6 +14,7 @@
 #include <linux/clk-provider.h>
 #include <linux/platform_device.h>
 #include <linux/of_address.h>
+#include <linux/regmap.h>
 
 #include "ccu_common.h"
 #include "ccu_reset.h"
@@ -1251,9 +1252,35 @@ static struct ccu_mux_nb sun8i_r40_cpu_nb = {
 	.bypass_index	= 1, /* index of 24 MHz oscillator */
 };
 
+/*
+ * Add a regmap for the GMAC driver (dwmac-sun8i) to access the
+ * GMAC configuration register.
+ * Only this register is allowed to be written, in order to
+ * prevent overriding critical clock configuration.
+ */
+
+#define SUN8I_R40_GMAC_CFG_REG 0x164
+static bool sun8i_r40_ccu_regmap_writeable_reg(struct device *dev,
+					       unsigned int reg)
+{
+	if (reg == SUN8I_R40_GMAC_CFG_REG)
+		return true;
+	return false;
+}
+
+static struct regmap_config sun8i_r40_ccu_regmap_config = {
+	.reg_bits	= 32,
+	.val_bits	= 32,
+	.reg_stride	= 4,
+	.max_register	= 0x320, /* PLL_LOCK_CTRL_REG */
+
+	.writeable_reg	= sun8i_r40_ccu_regmap_writeable_reg,
+};
+
 static int sun8i_r40_ccu_probe(struct platform_device *pdev)
 {
 	struct resource *res;
+	struct regmap *regmap;
 	void __iomem *reg;
 	u32 val;
 	int ret;
@@ -1278,6 +1305,11 @@ static int sun8i_r40_ccu_probe(struct platform_device *pdev)
 	val &= ~GENMASK(25, 20);
 	writel(val, reg + SUN8I_R40_USB_CLK_REG);
 
+	regmap = devm_regmap_init_mmio(&pdev->dev, reg,
+				       &sun8i_r40_ccu_regmap_config);
+	if (IS_ERR(regmap))
+		return PTR_ERR(regmap);
+
 	ret = sunxi_ccu_probe(pdev->dev.of_node, reg, &sun8i_r40_ccu_desc);
 	if (ret)
 		return ret;
-- 
2.13.6

[PATCH 0/2] Add a regmap to Allwinner R40 CCU to export GMAC register

[Maxime Ripard]

On Fri, Oct 06, 2017 at 06:33:31AM +0000, Icenowy Zheng wrote:
> In the CCU of the Allwinner R40 SoC, there's a GMAC configuration register,
> which is intended to be accessed by the dwmac-sun8i driver. On SoCs already
> supported by the driver the register is placed in the syscon rather than
> the CCU.
> 
> As CCU is a critical part of the SoC, so write to it should be strictly
> limited. A regmap with restricted write permission is created by the R40
> CCU driver, and can be get with dev_get_regmap. In order to tie the regmap
> to the CCU device, the R40 CCU is now a platform driver, so a platform
> device is created for it (and then tied with the regmap).
> 
> The first patch does the conversion of the driver to a platform driver,
> and the second patch adds the regmap.

I'd like to see first what you want to do with it.

Maxime

-- 
Maxime Ripard, Free Electrons
Embedded Linux and Kernel engineering
http://free-electrons.com
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[PATCH 0/2] Add a regmap to Allwinner R40 CCU to export GMAC register

[Icenowy Zheng]

? 2017?10?9? GMT+08:00 ??3:18:09, Maxime Ripard <maxime.ripard@free-electrons.com> ??:
>On Fri, Oct 06, 2017 at 06:33:31AM +0000, Icenowy Zheng wrote:
>> In the CCU of the Allwinner R40 SoC, there's a GMAC configuration
>register,
>> which is intended to be accessed by the dwmac-sun8i driver. On SoCs
>already
>> supported by the driver the register is placed in the syscon rather
>than
>> the CCU.
>> 
>> As CCU is a critical part of the SoC, so write to it should be
>strictly
>> limited. A regmap with restricted write permission is created by the
>R40
>> CCU driver, and can be get with dev_get_regmap. In order to tie the
>regmap
>> to the CCU device, the R40 CCU is now a platform driver, so a
>platform
>> device is created for it (and then tied with the regmap).
>> 
>> The first patch does the conversion of the driver to a platform
>driver,
>> and the second patch adds the regmap.
>
>I'd like to see first what you want to do with it.

Export the GMAC configuration register to dwmac-sun8i.

>
>Maxime

[PATCH 0/2] Add a regmap to Allwinner R40 CCU to export GMAC register

[Stephen Boyd]

On 10/09, Icenowy Zheng wrote:
> 
> 
> ? 2017?10?9? GMT+08:00 ??3:18:09, Maxime Ripard <maxime.ripard@free-electrons.com> ??:
> >On Fri, Oct 06, 2017 at 06:33:31AM +0000, Icenowy Zheng wrote:
> >> In the CCU of the Allwinner R40 SoC, there's a GMAC configuration
> >register,
> >> which is intended to be accessed by the dwmac-sun8i driver. On SoCs
> >already
> >> supported by the driver the register is placed in the syscon rather
> >than
> >> the CCU.
> >> 
> >> As CCU is a critical part of the SoC, so write to it should be
> >strictly
> >> limited. A regmap with restricted write permission is created by the
> >R40
> >> CCU driver, and can be get with dev_get_regmap. In order to tie the
> >regmap
> >> to the CCU device, the R40 CCU is now a platform driver, so a
> >platform
> >> device is created for it (and then tied with the regmap).
> >> 
> >> The first patch does the conversion of the driver to a platform
> >driver,
> >> and the second patch adds the regmap.
> >
> >I'd like to see first what you want to do with it.
> 
> Export the GMAC configuration register to dwmac-sun8i.
> 

Is this series going to be reposted?

-- 
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum,
a Linux Foundation Collaborative Project

[PATCH 0/2] Add a regmap to Allwinner R40 CCU to export GMAC register

[Icenowy Zheng]

? 2017-11-02 15:11?Stephen Boyd ???
> On 10/09, Icenowy Zheng wrote:
>> 
>> 
>> ? 2017?10?9? GMT+08:00 ??3:18:09, Maxime Ripard 
>> <maxime.ripard@free-electrons.com> ??:
>> >On Fri, Oct 06, 2017 at 06:33:31AM +0000, Icenowy Zheng wrote:
>> >> In the CCU of the Allwinner R40 SoC, there's a GMAC configuration
>> >register,
>> >> which is intended to be accessed by the dwmac-sun8i driver. On SoCs
>> >already
>> >> supported by the driver the register is placed in the syscon rather
>> >than
>> >> the CCU.
>> >>
>> >> As CCU is a critical part of the SoC, so write to it should be
>> >strictly
>> >> limited. A regmap with restricted write permission is created by the
>> >R40
>> >> CCU driver, and can be get with dev_get_regmap. In order to tie the
>> >regmap
>> >> to the CCU device, the R40 CCU is now a platform driver, so a
>> >platform
>> >> device is created for it (and then tied with the regmap).
>> >>
>> >> The first patch does the conversion of the driver to a platform
>> >driver,
>> >> and the second patch adds the regmap.
>> >
>> >I'd like to see first what you want to do with it.
>> 
>> Export the GMAC configuration register to dwmac-sun8i.
>> 
> 
> Is this series going to be reposted?

Yes, thanks.