diff options
author | Jernej Skrabec <jernej.skrabec@siol.net> | 2020-08-25 15:10:49 +0200 |
---|---|---|
committer | Maxime Ripard <maxime@cerno.tech> | 2020-08-25 16:42:55 +0200 |
commit | a3ba99a24b36bc4eee5413a820e2c4f3d81593fa (patch) | |
tree | f3389a3c2b4f980b9070ad8632b6afbeea3de263 /drivers | |
parent | fb038ce4db55cf2c911b6b221d10f06afe5f25af (diff) |
clk: sunxi-ng: sun8i: r40: Use sigma delta modulation for audio PLL
Audio cores need specific clock rates which can't be simply obtained by
adjusting integer multipliers and dividers. HW for such cases supports
delta-sigma modulation which enables fractional multipliers.
Port H3 delta-sigma table to R40. They have identical audio PLLs.
Signed-off-by: Jernej Skrabec <jernej.skrabec@siol.net>
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Link: https://lore.kernel.org/r/20200825131049.1277596-1-jernej.skrabec@siol.net
Diffstat (limited to 'drivers')
-rw-r--r-- | drivers/clk/sunxi-ng/ccu-sun8i-r40.c | 37 |
1 files changed, 24 insertions, 13 deletions
diff --git a/drivers/clk/sunxi-ng/ccu-sun8i-r40.c b/drivers/clk/sunxi-ng/ccu-sun8i-r40.c index 23bfe1d12f21..84153418453f 100644 --- a/drivers/clk/sunxi-ng/ccu-sun8i-r40.c +++ b/drivers/clk/sunxi-ng/ccu-sun8i-r40.c @@ -45,18 +45,29 @@ static struct ccu_nkmp pll_cpu_clk = { * the base (2x, 4x and 8x), and one variable divider (the one true * pll audio). * - * We don't have any need for the variable divider for now, so we just - * hardcode it to match with the clock names + * With sigma-delta modulation for fractional-N on the audio PLL, + * we have to use specific dividers. This means the variable divider + * can no longer be used, as the audio codec requests the exact clock + * rates we support through this mechanism. So we now hard code the + * variable divider to 1. This means the clock rates will no longer + * match the clock names. */ #define SUN8I_R40_PLL_AUDIO_REG 0x008 -static SUNXI_CCU_NM_WITH_GATE_LOCK(pll_audio_base_clk, "pll-audio-base", - "osc24M", 0x008, - 8, 7, /* N */ - 0, 5, /* M */ - BIT(31), /* gate */ - BIT(28), /* lock */ - CLK_SET_RATE_UNGATE); +static struct ccu_sdm_setting pll_audio_sdm_table[] = { + { .rate = 22579200, .pattern = 0xc0010d84, .m = 8, .n = 7 }, + { .rate = 24576000, .pattern = 0xc000ac02, .m = 14, .n = 14 }, +}; + +static SUNXI_CCU_NM_WITH_SDM_GATE_LOCK(pll_audio_base_clk, "pll-audio-base", + "osc24M", 0x008, + 8, 7, /* N */ + 0, 5, /* M */ + pll_audio_sdm_table, BIT(24), + 0x284, BIT(31), + BIT(31), /* gate */ + BIT(28), /* lock */ + CLK_SET_RATE_UNGATE); static SUNXI_CCU_NM_WITH_FRAC_GATE_LOCK_MIN_MAX(pll_video0_clk, "pll-video0", "osc24M", 0x0010, @@ -952,10 +963,10 @@ static const struct clk_hw *clk_parent_pll_audio[] = { &pll_audio_base_clk.common.hw }; -/* We hardcode the divider to 4 for now */ +/* We hardcode the divider to 1 for now */ static CLK_FIXED_FACTOR_HWS(pll_audio_clk, "pll-audio", clk_parent_pll_audio, - 4, 1, CLK_SET_RATE_PARENT); + 1, 1, CLK_SET_RATE_PARENT); static CLK_FIXED_FACTOR_HWS(pll_audio_2x_clk, "pll-audio-2x", clk_parent_pll_audio, 2, 1, CLK_SET_RATE_PARENT); @@ -1307,10 +1318,10 @@ static int sun8i_r40_ccu_probe(struct platform_device *pdev) if (IS_ERR(reg)) return PTR_ERR(reg); - /* Force the PLL-Audio-1x divider to 4 */ + /* Force the PLL-Audio-1x divider to 1 */ val = readl(reg + SUN8I_R40_PLL_AUDIO_REG); val &= ~GENMASK(19, 16); - writel(val | (3 << 16), reg + SUN8I_R40_PLL_AUDIO_REG); + writel(val | (0 << 16), reg + SUN8I_R40_PLL_AUDIO_REG); /* Force PLL-MIPI to MIPI mode */ val = readl(reg + SUN8I_R40_PLL_MIPI_REG); |