From: Dmitry Osipenko digetx@gmail.com
[ Upstream commit 514fddba845ed3a1b17e01e99cb3a2a52256a88a ]
Kernel should never gate the EMC clock as it causes immediate lockup, so removing clk-gate functionality doesn't affect anything. Turning EMC clk gate into divider allows to implement glitch-less EMC scaling, avoiding reparenting to a backup clock.
Signed-off-by: Dmitry Osipenko digetx@gmail.com Acked-by: Peter De Schrijver pdeschrijver@nvidia.com Acked-by: Stephen Boyd sboyd@kernel.org Signed-off-by: Thierry Reding treding@nvidia.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/clk/tegra/clk-tegra20.c | 36 ++++++++++++++++++++++++--------- 1 file changed, 26 insertions(+), 10 deletions(-)
diff --git a/drivers/clk/tegra/clk-tegra20.c b/drivers/clk/tegra/clk-tegra20.c index cc857d4d4a86e..68551effb5ca2 100644 --- a/drivers/clk/tegra/clk-tegra20.c +++ b/drivers/clk/tegra/clk-tegra20.c @@ -578,7 +578,6 @@ static struct tegra_clk tegra20_clks[tegra_clk_max] __initdata = { [tegra_clk_afi] = { .dt_id = TEGRA20_CLK_AFI, .present = true }, [tegra_clk_fuse] = { .dt_id = TEGRA20_CLK_FUSE, .present = true }, [tegra_clk_kfuse] = { .dt_id = TEGRA20_CLK_KFUSE, .present = true }, - [tegra_clk_emc] = { .dt_id = TEGRA20_CLK_EMC, .present = true }, };
static unsigned long tegra20_clk_measure_input_freq(void) @@ -799,6 +798,31 @@ static struct tegra_periph_init_data tegra_periph_nodiv_clk_list[] = { TEGRA_INIT_DATA_NODIV("disp2", mux_pllpdc_clkm, CLK_SOURCE_DISP2, 30, 2, 26, 0, TEGRA20_CLK_DISP2), };
+static void __init tegra20_emc_clk_init(void) +{ + struct clk *clk; + + clk = clk_register_mux(NULL, "emc_mux", mux_pllmcp_clkm, + ARRAY_SIZE(mux_pllmcp_clkm), + CLK_SET_RATE_NO_REPARENT, + clk_base + CLK_SOURCE_EMC, + 30, 2, 0, &emc_lock); + + clk = tegra_clk_register_mc("mc", "emc_mux", clk_base + CLK_SOURCE_EMC, + &emc_lock); + clks[TEGRA20_CLK_MC] = clk; + + /* + * 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 + * defining 'emc_mux' and 'emc' as distinct clocks. + */ + clk = tegra_clk_register_divider("emc", "emc_mux", + clk_base + CLK_SOURCE_EMC, CLK_IS_CRITICAL, + TEGRA_DIVIDER_INT, 0, 8, 1, &emc_lock); + clks[TEGRA20_CLK_EMC] = clk; +} + static void __init tegra20_periph_clk_init(void) { struct tegra_periph_init_data *data; @@ -812,15 +836,7 @@ static void __init tegra20_periph_clk_init(void) clks[TEGRA20_CLK_AC97] = clk;
/* emc */ - clk = clk_register_mux(NULL, "emc_mux", mux_pllmcp_clkm, - ARRAY_SIZE(mux_pllmcp_clkm), - CLK_SET_RATE_NO_REPARENT, - clk_base + CLK_SOURCE_EMC, - 30, 2, 0, &emc_lock); - - clk = tegra_clk_register_mc("mc", "emc_mux", clk_base + CLK_SOURCE_EMC, - &emc_lock); - clks[TEGRA20_CLK_MC] = clk; + tegra20_emc_clk_init();
/* dsi */ clk = tegra_clk_register_periph_gate("dsi", "pll_d", 0, clk_base, 0,