diff options
| author | Dmitry Osipenko <digetx@gmail.com> | 2018-10-21 21:30:50 +0300 |
|---|---|---|
| committer | Thierry Reding <treding@nvidia.com> | 2018-11-08 14:47:17 +0300 |
| commit | 514fddba845ed3a1b17e01e99cb3a2a52256a88a (patch) | |
| tree | e2e879b87eaf6c4b85fbb1ef77a1743c31e4e3a2 /drivers/clk/tegra/clk-tegra20.c | |
| parent | 651022382c7f8da46cb4872a545ee1da6d097d2a (diff) | |
| download | linux-514fddba845ed3a1b17e01e99cb3a2a52256a88a.tar.xz | |
clk: tegra20: Turn EMC clock gate into divider
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>
Diffstat (limited to 'drivers/clk/tegra/clk-tegra20.c')
| -rw-r--r-- | drivers/clk/tegra/clk-tegra20.c | 36 |
1 files changed, 26 insertions, 10 deletions
diff --git a/drivers/clk/tegra/clk-tegra20.c b/drivers/clk/tegra/clk-tegra20.c index cc857d4d4a86..68551effb5ca 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, |