[PATCH v2 1/6] clk: sunxi-ng: a20: Register regmap for sun7i CCU

From: Priit Laes
Date: Wed Apr 29 2020 - 16:46:27 EST


On sun7i, the gmac clock is handled by the dwmac-sunxi driver, but
its configuration register is located in the CCU register range,
requiring proper regmap setup.

In order to do that, we use CLK_OF_DECLARE_DRIVER to initialize
sun7i ccu, which clears the OF_POPULATED flag, allowing the
platform device to probe the same resource with proper device node.

Signed-off-by: Priit Laes <plaes@xxxxxxxxx>
---
drivers/clk/sunxi-ng/ccu-sun4i-a10.c | 60 +++++++++++++++++++++++++++-
1 file changed, 59 insertions(+), 1 deletion(-)

diff --git a/drivers/clk/sunxi-ng/ccu-sun4i-a10.c b/drivers/clk/sunxi-ng/ccu-sun4i-a10.c
index f32366d9336e..fbdf9ecf21b8 100644
--- a/drivers/clk/sunxi-ng/ccu-sun4i-a10.c
+++ b/drivers/clk/sunxi-ng/ccu-sun4i-a10.c
@@ -8,6 +8,8 @@
#include <linux/clk-provider.h>
#include <linux/io.h>
#include <linux/of_address.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>

#include "ccu_common.h"
#include "ccu_reset.h"
@@ -1478,5 +1480,61 @@ static void __init sun7i_a20_ccu_setup(struct device_node *node)
{
sun4i_ccu_init(node, &sun7i_a20_ccu_desc);
}
-CLK_OF_DECLARE(sun7i_a20_ccu, "allwinner,sun7i-a20-ccu",
+CLK_OF_DECLARE_DRIVER(sun7i_a20_ccu, "allwinner,sun7i-a20-ccu",
sun7i_a20_ccu_setup);
+
+/*
+ * Regmap for the GMAC driver (dwmac-sunxi) to allow access to
+ * GMAC configuration register.
+ */
+#define SUN7I_A20_GMAC_CFG_REG 0x164
+static bool sun7i_a20_ccu_regmap_accessible_reg(struct device *dev,
+ unsigned int reg)
+{
+ if (reg == SUN7I_A20_GMAC_CFG_REG)
+ return true;
+ return false;
+}
+
+static struct regmap_config sun7i_a20_ccu_regmap_config = {
+ .reg_bits = 32,
+ .val_bits = 32,
+ .reg_stride = 4,
+ .max_register = 0x1f4, /* clk_out_b */
+
+ .readable_reg = sun7i_a20_ccu_regmap_accessible_reg,
+ .writeable_reg = sun7i_a20_ccu_regmap_accessible_reg,
+};
+
+static int sun7i_a20_ccu_probe_regmap(struct platform_device *pdev)
+{
+ void __iomem *reg;
+ struct resource *res;
+ struct regmap *regmap;
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ reg = devm_ioremap(&pdev->dev, res->start, resource_size(res));
+ if (IS_ERR(reg))
+ return PTR_ERR(reg);
+
+ regmap = devm_regmap_init_mmio(&pdev->dev, reg,
+ &sun7i_a20_ccu_regmap_config);
+ if (IS_ERR(regmap))
+ return PTR_ERR(regmap);
+
+ return 0;
+}
+
+static const struct of_device_id sun7i_a20_ccu_ids[] = {
+ { .compatible = "allwinner,sun7i-a20-ccu"},
+ { }
+};
+
+static struct platform_driver sun7i_a20_ccu_driver = {
+ .probe = sun7i_a20_ccu_probe_regmap,
+ .driver = {
+ .name = "sun7i-a20-ccu",
+ .of_match_table = sun7i_a20_ccu_ids,
+ },
+};
+builtin_platform_driver(sun7i_a20_ccu_driver);
--
2.26.2