Thread (13 messages) 13 messages, 6 authors, 2020-07-03

Re: [PATCH v4 1/2] clk: rockchip: rk3288: Handle clock tree for rk3288w

From: Heiko Stuebner <heiko@sntech.de>
Date: 2020-07-03 15:05:19
Also in: linux-clk, linux-devicetree, linux-rockchip, lkml

Am Freitag, 3. Juli 2020, 17:02:52 CEST schrieb Ezequiel Garcia:
On Fri, 2020-07-03 at 16:11 +0200, Heiko Stuebner wrote:
quoted
Hi Jagan,

Am Montag, 29. Juni 2020, 21:11:03 CEST schrieb Jagan Teki:
quoted
On Tue, Jun 2, 2020 at 1:37 PM Mylène Josserand
[off-list ref] wrote:
quoted
The revision rk3288w has a different clock tree about "hclk_vio"
clock, according to the BSP kernel code.

This patch handles this difference by detecting which device-tree
we are using. If it is a "rockchip,rk3288-cru", let's register
the clock tree as it was before. If the device-tree node is
"rockchip,rk3288w-cru", we will apply the difference with this
version of this SoC.

Noticed that this new device-tree compatible must be handled in
bootloader such as u-boot.

Signed-off-by: Mylène Josserand <redacted>
---
 drivers/clk/rockchip/clk-rk3288.c | 20 ++++++++++++++++++--
 1 file changed, 18 insertions(+), 2 deletions(-)
diff --git a/drivers/clk/rockchip/clk-rk3288.c b/drivers/clk/rockchip/clk-rk3288.c
index cc2a177bbdbf..204976e2d0cb 100644
--- a/drivers/clk/rockchip/clk-rk3288.c
+++ b/drivers/clk/rockchip/clk-rk3288.c
@@ -425,8 +425,6 @@ static struct rockchip_clk_branch rk3288_clk_branches[] __initdata = {
        COMPOSITE(0, "aclk_vio0", mux_pll_src_cpll_gpll_usb480m_p, CLK_IGNORE_UNUSED,
                        RK3288_CLKSEL_CON(31), 6, 2, MFLAGS, 0, 5, DFLAGS,
                        RK3288_CLKGATE_CON(3), 0, GFLAGS),
-       DIV(0, "hclk_vio", "aclk_vio0", 0,
-                       RK3288_CLKSEL_CON(28), 8, 5, DFLAGS),
        COMPOSITE(0, "aclk_vio1", mux_pll_src_cpll_gpll_usb480m_p, CLK_IGNORE_UNUSED,
                        RK3288_CLKSEL_CON(31), 14, 2, MFLAGS, 8, 5, DFLAGS,
                        RK3288_CLKGATE_CON(3), 2, GFLAGS),
@@ -819,6 +817,16 @@ static struct rockchip_clk_branch rk3288_clk_branches[] __initdata = {
        INVERTER(0, "pclk_isp", "pclk_isp_in", RK3288_CLKSEL_CON(29), 3, IFLAGS),
 };

+static struct rockchip_clk_branch rk3288w_hclkvio_branch[] __initdata = {
+       DIV(0, "hclk_vio", "aclk_vio1", 0,
+                       RK3288_CLKSEL_CON(28), 8, 5, DFLAGS),
+};
+
+static struct rockchip_clk_branch rk3288_hclkvio_branch[] __initdata = {
+       DIV(0, "hclk_vio", "aclk_vio0", 0,
+                       RK3288_CLKSEL_CON(28), 8, 5, DFLAGS),
+};
+
 static const char *const rk3288_critical_clocks[] __initconst = {
        "aclk_cpu",
        "aclk_peri",
@@ -936,6 +944,14 @@ static void __init rk3288_clk_init(struct device_node *np)
                                   RK3288_GRF_SOC_STATUS1);
        rockchip_clk_register_branches(ctx, rk3288_clk_branches,
                                  ARRAY_SIZE(rk3288_clk_branches));
+
+       if (of_device_is_compatible(np, "rockchip,rk3288w-cru"))
+               rockchip_clk_register_branches(ctx, rk3288w_hclkvio_branch,
+                                              ARRAY_SIZE(rk3288w_hclkvio_branch));
+       else
+               rockchip_clk_register_branches(ctx, rk3288_hclkvio_branch,
+                                              ARRAY_SIZE(rk3288_hclkvio_branch));
+
Sorry for the late query on this. I am a bit unclear about this
compatible change, does Linux expect to replace rockchip,rk3288-cru
with rockchip,rk3288w-cru in bootloader if the chip is RK3288w? or
append the existing cru compatible node with rockchip,rk3288w-cru?
because replace new cru node make clock never probe since the
CLK_OF_DECLARE checking rockchip,rk3288-cru
I guess right now we'd expect "rockchip,rk3288w-cru", "rockchip,rk3288-cru",

Thinking again about this, I'm wondering if we should switch to having
only one per variant ... like on the two rk3188 variants,
so declaring separate rk3288-cru and rk3288w-cru of-clks with shared
common code.
If we want to take this route (which I think makes sense), we should
do that sooner than later, so we don't release two different implementations
with two different requirements.

This change should be quite simple, no?
the underlying change is queued for 5.9, but yeah I am currently testing
exactly such a patch ;-)
Especially as when reading the binding addition it states
rk3288w-cru _or_ rk3288-cru for the compatible.


Heiko



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