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clk: samsung: gs101: propagate PERIC1 USI SPI clock rate
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When SPI transfer is being prepared, the spi-s3c64xx driver will call
clk_set_rate() to change the rate of SPI source clock (IPCLK). But IPCLK
is a gate (leaf) clock, so it must propagate the rate change up the
clock tree, so that corresponding MUX/DIV clocks can actually change
their values. Add CLK_SET_RATE_PARENT flag to corresponding clocks for
all USI instances in GS101 PERIC1: USI{0, 9, 10, 11, 12, 13}. This change
involves the following clocks:

PERIC1 USI*:

    Clock                              Div range    MUX Selection
    -------------------------------------------------------------------
    gout_peric1_peric1_top0_ipclk_*    -            -
    dout_peric1_usi*_usi               /1..16       -
    mout_peric1_usi*_usi_user          -            {24.5 MHz, 400 MHz}

With input clock of 400 MHz this scheme provides the following IPCLK
rate range, for each USI block:

    PERIC1 USI*:       1.5 MHz ... 400 MHz

Accounting for internal /4 divider in SPI blocks, and because the max
SPI frequency is limited at 50 MHz, it gives us next SPI SCK rates:

    PERIC1 USI_SPI*:   384 KHz ... 49.9 MHz

Which shall be fine for the applications of the SPI bus.

Note that with this we allow the reparenting of the MUX_USIx clocks to
OSCCLK. Each instance of the USI IP has its own MUX_USI clock, thus the
reparenting of a MUX_USI clock corresponds to a single instance of the
USI IP. The datasheet mentions OSCCLK just in the low-power mode
context, but the downstream driver reparents too the MUX_USI clocks to
OSCCLK. Follow the downstream driver and do the same.

Fixes: 2999e78 ("clk: samsung: gs101: add support for cmu_peric1")
Reviewed-by: Peter Griffin <peter.griffin@linaro.org>
Acked-by: André Draszik <andre.draszik@linaro.org>
Signed-off-by: Tudor Ambarus <tudor.ambarus@linaro.org>
Link: https://lore.kernel.org/r/20240419100915.2168573-3-tudor.ambarus@linaro.org
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
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@ambarus @krzk
ambarus authored and krzk committed Apr 22, 2024
1 parent 7b54d91 commit 7cf0324
Showing 1 changed file with 48 additions and 42 deletions.
90 changes: 48 additions & 42 deletions drivers/clk/samsung/clk-gs101.c
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Original file line number Diff line number Diff line change
Expand Up @@ -3239,47 +3239,53 @@ static const struct samsung_mux_clock peric1_mux_clks[] __initconst = {
MUX(CLK_MOUT_PERIC1_I3C_USER,
"mout_peric1_i3c_user", mout_peric1_nonbususer_p,
PLL_CON0_MUX_CLKCMU_PERIC1_I3C_USER, 4, 1),
MUX(CLK_MOUT_PERIC1_USI0_USI_USER,
"mout_peric1_usi0_usi_user", mout_peric1_nonbususer_p,
PLL_CON0_MUX_CLKCMU_PERIC1_USI0_USI_USER, 4, 1),
MUX(CLK_MOUT_PERIC1_USI10_USI_USER,
"mout_peric1_usi10_usi_user", mout_peric1_nonbususer_p,
PLL_CON0_MUX_CLKCMU_PERIC1_USI10_USI_USER, 4, 1),
MUX(CLK_MOUT_PERIC1_USI11_USI_USER,
"mout_peric1_usi11_usi_user", mout_peric1_nonbususer_p,
PLL_CON0_MUX_CLKCMU_PERIC1_USI11_USI_USER, 4, 1),
MUX(CLK_MOUT_PERIC1_USI12_USI_USER,
"mout_peric1_usi12_usi_user", mout_peric1_nonbususer_p,
PLL_CON0_MUX_CLKCMU_PERIC1_USI12_USI_USER, 4, 1),
MUX(CLK_MOUT_PERIC1_USI13_USI_USER,
"mout_peric1_usi13_usi_user", mout_peric1_nonbususer_p,
PLL_CON0_MUX_CLKCMU_PERIC1_USI13_USI_USER, 4, 1),
MUX(CLK_MOUT_PERIC1_USI9_USI_USER,
"mout_peric1_usi9_usi_user", mout_peric1_nonbususer_p,
PLL_CON0_MUX_CLKCMU_PERIC1_USI9_USI_USER, 4, 1),
nMUX(CLK_MOUT_PERIC1_USI0_USI_USER,
"mout_peric1_usi0_usi_user", mout_peric1_nonbususer_p,
PLL_CON0_MUX_CLKCMU_PERIC1_USI0_USI_USER, 4, 1),
nMUX(CLK_MOUT_PERIC1_USI10_USI_USER,
"mout_peric1_usi10_usi_user", mout_peric1_nonbususer_p,
PLL_CON0_MUX_CLKCMU_PERIC1_USI10_USI_USER, 4, 1),
nMUX(CLK_MOUT_PERIC1_USI11_USI_USER,
"mout_peric1_usi11_usi_user", mout_peric1_nonbususer_p,
PLL_CON0_MUX_CLKCMU_PERIC1_USI11_USI_USER, 4, 1),
nMUX(CLK_MOUT_PERIC1_USI12_USI_USER,
"mout_peric1_usi12_usi_user", mout_peric1_nonbususer_p,
PLL_CON0_MUX_CLKCMU_PERIC1_USI12_USI_USER, 4, 1),
nMUX(CLK_MOUT_PERIC1_USI13_USI_USER,
"mout_peric1_usi13_usi_user", mout_peric1_nonbususer_p,
PLL_CON0_MUX_CLKCMU_PERIC1_USI13_USI_USER, 4, 1),
nMUX(CLK_MOUT_PERIC1_USI9_USI_USER,
"mout_peric1_usi9_usi_user", mout_peric1_nonbususer_p,
PLL_CON0_MUX_CLKCMU_PERIC1_USI9_USI_USER, 4, 1),
};

static const struct samsung_div_clock peric1_div_clks[] __initconst = {
DIV(CLK_DOUT_PERIC1_I3C, "dout_peric1_i3c", "mout_peric1_i3c_user",
CLK_CON_DIV_DIV_CLK_PERIC1_I3C, 0, 4),
DIV(CLK_DOUT_PERIC1_USI0_USI,
"dout_peric1_usi0_usi", "mout_peric1_usi0_usi_user",
CLK_CON_DIV_DIV_CLK_PERIC1_USI0_USI, 0, 4),
DIV(CLK_DOUT_PERIC1_USI10_USI,
"dout_peric1_usi10_usi", "mout_peric1_usi10_usi_user",
CLK_CON_DIV_DIV_CLK_PERIC1_USI10_USI, 0, 4),
DIV(CLK_DOUT_PERIC1_USI11_USI,
"dout_peric1_usi11_usi", "mout_peric1_usi11_usi_user",
CLK_CON_DIV_DIV_CLK_PERIC1_USI11_USI, 0, 4),
DIV(CLK_DOUT_PERIC1_USI12_USI,
"dout_peric1_usi12_usi", "mout_peric1_usi12_usi_user",
CLK_CON_DIV_DIV_CLK_PERIC1_USI12_USI, 0, 4),
DIV(CLK_DOUT_PERIC1_USI13_USI,
"dout_peric1_usi13_usi", "mout_peric1_usi13_usi_user",
CLK_CON_DIV_DIV_CLK_PERIC1_USI13_USI, 0, 4),
DIV(CLK_DOUT_PERIC1_USI9_USI,
"dout_peric1_usi9_usi", "mout_peric1_usi9_usi_user",
CLK_CON_DIV_DIV_CLK_PERIC1_USI9_USI, 0, 4),
DIV_F(CLK_DOUT_PERIC1_USI0_USI,
"dout_peric1_usi0_usi", "mout_peric1_usi0_usi_user",
CLK_CON_DIV_DIV_CLK_PERIC1_USI0_USI, 0, 4,
CLK_SET_RATE_PARENT, 0),
DIV_F(CLK_DOUT_PERIC1_USI10_USI,
"dout_peric1_usi10_usi", "mout_peric1_usi10_usi_user",
CLK_CON_DIV_DIV_CLK_PERIC1_USI10_USI, 0, 4,
CLK_SET_RATE_PARENT, 0),
DIV_F(CLK_DOUT_PERIC1_USI11_USI,
"dout_peric1_usi11_usi", "mout_peric1_usi11_usi_user",
CLK_CON_DIV_DIV_CLK_PERIC1_USI11_USI, 0, 4,
CLK_SET_RATE_PARENT, 0),
DIV_F(CLK_DOUT_PERIC1_USI12_USI,
"dout_peric1_usi12_usi", "mout_peric1_usi12_usi_user",
CLK_CON_DIV_DIV_CLK_PERIC1_USI12_USI, 0, 4,
CLK_SET_RATE_PARENT, 0),
DIV_F(CLK_DOUT_PERIC1_USI13_USI,
"dout_peric1_usi13_usi", "mout_peric1_usi13_usi_user",
CLK_CON_DIV_DIV_CLK_PERIC1_USI13_USI, 0, 4,
CLK_SET_RATE_PARENT, 0),
DIV_F(CLK_DOUT_PERIC1_USI9_USI,
"dout_peric1_usi9_usi", "mout_peric1_usi9_usi_user",
CLK_CON_DIV_DIV_CLK_PERIC1_USI9_USI, 0, 4,
CLK_SET_RATE_PARENT, 0),
};

static const struct samsung_gate_clock peric1_gate_clks[] __initconst = {
Expand Down Expand Up @@ -3314,27 +3320,27 @@ static const struct samsung_gate_clock peric1_gate_clks[] __initconst = {
GATE(CLK_GOUT_PERIC1_PERIC1_TOP0_IPCLK_1,
"gout_peric1_peric1_top0_ipclk_1", "dout_peric1_usi0_usi",
CLK_CON_GAT_GOUT_BLK_PERIC1_UID_PERIC1_TOP0_IPCLKPORT_IPCLK_1,
21, 0, 0),
21, CLK_SET_RATE_PARENT, 0),
GATE(CLK_GOUT_PERIC1_PERIC1_TOP0_IPCLK_2,
"gout_peric1_peric1_top0_ipclk_2", "dout_peric1_usi9_usi",
CLK_CON_GAT_GOUT_BLK_PERIC1_UID_PERIC1_TOP0_IPCLKPORT_IPCLK_2,
21, 0, 0),
21, CLK_SET_RATE_PARENT, 0),
GATE(CLK_GOUT_PERIC1_PERIC1_TOP0_IPCLK_3,
"gout_peric1_peric1_top0_ipclk_3", "dout_peric1_usi10_usi",
CLK_CON_GAT_GOUT_BLK_PERIC1_UID_PERIC1_TOP0_IPCLKPORT_IPCLK_3,
21, 0, 0),
21, CLK_SET_RATE_PARENT, 0),
GATE(CLK_GOUT_PERIC1_PERIC1_TOP0_IPCLK_4,
"gout_peric1_peric1_top0_ipclk_4", "dout_peric1_usi11_usi",
CLK_CON_GAT_GOUT_BLK_PERIC1_UID_PERIC1_TOP0_IPCLKPORT_IPCLK_4,
21, 0, 0),
21, CLK_SET_RATE_PARENT, 0),
GATE(CLK_GOUT_PERIC1_PERIC1_TOP0_IPCLK_5,
"gout_peric1_peric1_top0_ipclk_5", "dout_peric1_usi12_usi",
CLK_CON_GAT_GOUT_BLK_PERIC1_UID_PERIC1_TOP0_IPCLKPORT_IPCLK_5,
21, 0, 0),
21, CLK_SET_RATE_PARENT, 0),
GATE(CLK_GOUT_PERIC1_PERIC1_TOP0_IPCLK_6,
"gout_peric1_peric1_top0_ipclk_6", "dout_peric1_usi13_usi",
CLK_CON_GAT_GOUT_BLK_PERIC1_UID_PERIC1_TOP0_IPCLKPORT_IPCLK_6,
21, 0, 0),
21, CLK_SET_RATE_PARENT, 0),
GATE(CLK_GOUT_PERIC1_PERIC1_TOP0_IPCLK_8,
"gout_peric1_peric1_top0_ipclk_8", "dout_peric1_i3c",
CLK_CON_GAT_GOUT_BLK_PERIC1_UID_PERIC1_TOP0_IPCLKPORT_IPCLK_8,
Expand Down

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