[PATCH v3 7/8] clk: tegra20: Check whether direct PLLM sourcing is turned off for EMC

Dmitry Osipenko
2018-06-17T15:01:10Z

Ensure that direct PLLM sourcing is turned off for EMC as we don't support
that configuration in the clk driver.

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Acked-by: Peter De Schrijver <pdeschrijver@nvidia.com>
---
drivers/clk/tegra/clk-tegra20.c | 10 ++++++++++
1 file changed, 10 insertions(+)

diff --git a/drivers/clk/tegra/clk-tegra20.c b/drivers/clk/tegra/clk-tegra20.c
index 2bd35418716a..ca4eadb9520e 100644
--- a/drivers/clk/tegra/clk-tegra20.c
+++ b/drivers/clk/tegra/clk-tegra20.c
@@ -800,7 +800,9 @@ static struct tegra_periph_init_data tegra_periph_nodiv_clk_list[] = {

static void __init tegra20_emc_clk_init(void)
{
+ const u32 use_pllm_ud = BIT(29);
struct clk *clk;
+ u32 emc_reg;

clk = clk_register_mux(NULL, "emc_mux", mux_pllmcp_clkm,
ARRAY_SIZE(mux_pllmcp_clkm),
@@ -812,6 +814,14 @@ static void __init tegra20_emc_clk_init(void)
&emc_lock);
clks[TEGRA20_CLK_MC] = clk;

+ /* un-divided pll_m_out0 is currently unsupported */
+ emc_reg = readl_relaxed(clk_base + CLK_SOURCE_EMC);
+ if (emc_reg & use_pllm_ud) {
+ pr_err("%s: un-divided PllM_out0 used as clock source\n",
+ __func__);
+ return;
+ }
+
/*
* Note that 'emc_mux' source and 'emc' rate shouldn't be changed at
* the same time due to a HW bug, this won't happen because we're
--
2.17.1