[PATCH net-next v2 02/15] clk: sunxi-ng: r40: export a regmap to access the GMAC register

Chen-Yu Tsai
2018-05-01T16:12:14Z

From: Icenowy Zheng <icenowy@aosc.io>

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>
Signed-off-by: Chen-Yu Tsai <wens@csie.org>
---
drivers/clk/sunxi-ng/ccu-sun8i-r40.c | 33 ++++++++++++++++++++++++++++
1 file changed, 33 insertions(+)

diff --git a/drivers/clk/sunxi-ng/ccu-sun8i-r40.c b/drivers/clk/sunxi-ng/ccu-sun8i-r40.c
index c3aa839a453d..65ba6455feb7 100644
--- a/drivers/clk/sunxi-ng/ccu-sun8i-r40.c
+++ b/drivers/clk/sunxi-ng/ccu-sun8i-r40.c
@@ -1251,9 +1251,37 @@ 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_accessible_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 */
+
+ /* other devices have no business accessing other registers */
+ .readable_reg = sun8i_r40_ccu_regmap_accessible_reg,
+ .writeable_reg = sun8i_r40_ccu_regmap_accessible_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 +1306,11 @@ 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;
--
2.17.0