[PATCH 5.4 173/344] clk: sunxi-ng: add mux and pll notifiers for A64 CPU clock

Greg Kroah-Hartman
2020-02-21T08:34:52Z

From: Icenowy Zheng <icenowy@aosc.io>

[ Upstream commit ec97faff743b398e21f74a54c81333f3390093aa ]

The A64 PLL_CPU clock has the same instability if some factor changed
without the PLL gated like other SoCs with sun6i-style CCU, e.g. A33,
H3.

Add the mux and pll notifiers for A64 CPU clock to workaround the
problem.

Fixes: c6a0637460c2 ("clk: sunxi-ng: Add A64 clocks")
Signed-off-by: Icenowy Zheng <icenowy@aosc.io>
Signed-off-by: Vasily Khoruzhick <anarsoul@gmail.com>
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/clk/sunxi-ng/ccu-sun50i-a64.c | 28 ++++++++++++++++++++++++++-
1 file changed, 27 insertions(+), 1 deletion(-)

diff --git a/drivers/clk/sunxi-ng/ccu-sun50i-a64.c b/drivers/clk/sunxi-ng/ccu-sun50i-a64.c
index 49bd7a4c015c4..5f66bf8797723 100644
--- a/drivers/clk/sunxi-ng/ccu-sun50i-a64.c
+++ b/drivers/clk/sunxi-ng/ccu-sun50i-a64.c
@@ -921,11 +921,26 @@ static const struct sunxi_ccu_desc sun50i_a64_ccu_desc = {
.num_resets = ARRAY_SIZE(sun50i_a64_ccu_resets),
};

+static struct ccu_pll_nb sun50i_a64_pll_cpu_nb = {
+ .common = &pll_cpux_clk.common,
+ /* copy from pll_cpux_clk */
+ .enable = BIT(31),
+ .lock = BIT(28),
+};
+
+static struct ccu_mux_nb sun50i_a64_cpu_nb = {
+ .common = &cpux_clk.common,
+ .cm = &cpux_clk.mux,
+ .delay_us = 1, /* > 8 clock cycles at 24 MHz */
+ .bypass_index = 1, /* index of 24 MHz oscillator */
+};
+
static int sun50i_a64_ccu_probe(struct platform_device *pdev)
{
struct resource *res;
void __iomem *reg;
u32 val;
+ int ret;

res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
reg = devm_ioremap_resource(&pdev->dev, res);
@@ -939,7 +954,18 @@ static int sun50i_a64_ccu_probe(struct platform_device *pdev)

writel(0x515, reg + SUN50I_A64_PLL_MIPI_REG);

- return sunxi_ccu_probe(pdev->dev.of_node, reg, &sun50i_a64_ccu_desc);
+ ret = sunxi_ccu_probe(pdev->dev.of_node, reg, &sun50i_a64_ccu_desc);
+ if (ret)
+ return ret;
+
+ /* Gate then ungate PLL CPU after any rate changes */
+ ccu_pll_notifier_register(&sun50i_a64_pll_cpu_nb);
+
+ /* Reparent CPU during PLL CPU rate changes */
+ ccu_mux_notifier_register(pll_cpux_clk.common.hw.clk,
+ &sun50i_a64_cpu_nb);
+
+ return 0;
}

static const struct of_device_id sun50i_a64_ccu_ids[] = {
--
2.20.1