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author | Martin Blumenstingl <martin.blumenstingl@googlemail.com> | 2018-04-23 21:35:09 +0200 |
---|---|---|
committer | Jerome Brunet <jbrunet@baylibre.com> | 2018-05-15 14:18:38 +0200 |
commit | b8c1ddadc8155831bae6fed85204221eff203f9e (patch) | |
tree | 777212de169ef555bf7534a066895dec217a6275 /drivers/clk | |
parent | a0b5e4e4be0cf97b101eaf1a039a3a71c3fe0e66 (diff) | |
download | linux-b8c1ddadc8155831bae6fed85204221eff203f9e.tar.gz linux-b8c1ddadc8155831bae6fed85204221eff203f9e.tar.bz2 linux-b8c1ddadc8155831bae6fed85204221eff203f9e.zip |
clk: meson: meson8b: add support for the NAND clocks
This adds the NAND clocks (from the HHI_NAND_CLK_CNTL register) to the
Meson8b clock driver. There are three NAND clocks: a gate which enables
or disables the NAND clock, a mux and a divider (which divides the mux
output).
Unfortunately the public S805 datasheet does not document the mux
parents. However, the vendor kernel has a few hints for us which allows
us to make an educated guess about the clock parents. To do this we need
to have a look at set_nand_core_clk() from the vendor's NAND driver (see
[0]):
- XTAL = (4<<9) | (1<<8) | 0
- 160MHz = (0<<9) | (1<<8) | 3)
- 182MHz = (3<<9) | (1<<8) | 1)
- 212MHz = (1<<9) | (1<<8) | 3)
- 255MHz = (2<<9) | (1<<8) | 1)
While there is a comment for the XTAL parent (which indicates that it
should only be used for debugging) we have to do a bit of math for the
other parents: target_freq * divider = rate of parent clock
Bit 8 above is the enable bit, so we can ignore it here. Bits 11:9 are
the mux index and bits 6:0 are the 0-based divider (so we need to add
1). This gives us:
- mux 0 (160MHz * 4) = fclk_div4 (actual rate = 637.5MHz, off by 2.5MHz)
- mux 1 (212MHz * 4) = fclk_div3 (actual rate = 850MHz, off by 2MHz)
- mux 2 (255MHz * 2) = fclk_div5 (matches exactly 510MHz)
- mux 3 (182MHz * 2) = fclk_div7 (actual rate = 346.3MHz, off by 0.3MHz)
[0] https://github.com/khadas/linux/blob/9587681285cb/drivers/amlogic/amlnf/dev/amlnf_ctrl.c#L314
Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>
Diffstat (limited to 'drivers/clk')
-rw-r--r-- | drivers/clk/meson/meson8b.c | 54 | ||||
-rw-r--r-- | drivers/clk/meson/meson8b.h | 5 |
2 files changed, 58 insertions, 1 deletions
diff --git a/drivers/clk/meson/meson8b.c b/drivers/clk/meson/meson8b.c index cc2992493e0b..e6e9a9db1095 100644 --- a/drivers/clk/meson/meson8b.c +++ b/drivers/clk/meson/meson8b.c @@ -639,6 +639,54 @@ static struct clk_regmap meson8b_cpu_clk = { }, }; +static struct clk_regmap meson8b_nand_clk_sel = { + .data = &(struct clk_regmap_mux_data){ + .offset = HHI_NAND_CLK_CNTL, + .mask = 0x7, + .shift = 9, + .flags = CLK_MUX_ROUND_CLOSEST, + }, + .hw.init = &(struct clk_init_data){ + .name = "nand_clk_sel", + .ops = &clk_regmap_mux_ops, + /* FIXME all other parents are unknown: */ + .parent_names = (const char *[]){ "fclk_div4", "fclk_div3", + "fclk_div5", "fclk_div7", "xtal" }, + .num_parents = 5, + .flags = CLK_SET_RATE_PARENT, + }, +}; + +static struct clk_regmap meson8b_nand_clk_div = { + .data = &(struct clk_regmap_div_data){ + .offset = HHI_NAND_CLK_CNTL, + .shift = 0, + .width = 7, + .flags = CLK_DIVIDER_ROUND_CLOSEST, + }, + .hw.init = &(struct clk_init_data){ + .name = "nand_clk_div", + .ops = &clk_regmap_divider_ops, + .parent_names = (const char *[]){ "nand_clk_sel" }, + .num_parents = 1, + .flags = CLK_SET_RATE_PARENT, + }, +}; + +static struct clk_regmap meson8b_nand_clk_gate = { + .data = &(struct clk_regmap_gate_data){ + .offset = HHI_NAND_CLK_CNTL, + .bit_idx = 8, + }, + .hw.init = &(struct clk_init_data){ + .name = "nand_clk_gate", + .ops = &clk_regmap_gate_ops, + .parent_names = (const char *[]){ "nand_clk_div" }, + .num_parents = 1, + .flags = CLK_SET_RATE_PARENT, + }, +}; + /* Everything Else (EE) domain gates */ static MESON_GATE(meson8b_ddr, HHI_GCLK_MPEG0, 0); @@ -834,6 +882,9 @@ static struct clk_hw_onecell_data meson8b_hw_onecell_data = { [CLKID_FCLK_DIV4_DIV] = &meson8b_fclk_div4_div.hw, [CLKID_FCLK_DIV5_DIV] = &meson8b_fclk_div5_div.hw, [CLKID_FCLK_DIV7_DIV] = &meson8b_fclk_div7_div.hw, + [CLKID_NAND_SEL] = &meson8b_nand_clk_sel.hw, + [CLKID_NAND_DIV] = &meson8b_nand_clk_div.hw, + [CLKID_NAND_CLK] = &meson8b_nand_clk_gate.hw, [CLK_NR_CLKS] = NULL, }, .num = CLK_NR_CLKS, @@ -939,6 +990,9 @@ static struct clk_regmap *const meson8b_clk_regmaps[] = { &meson8b_fclk_div4, &meson8b_fclk_div5, &meson8b_fclk_div7, + &meson8b_nand_clk_sel, + &meson8b_nand_clk_div, + &meson8b_nand_clk_gate, }; static const struct meson8b_clk_reset_line { diff --git a/drivers/clk/meson/meson8b.h b/drivers/clk/meson/meson8b.h index 6e414bd36981..a687dc60b6d0 100644 --- a/drivers/clk/meson/meson8b.h +++ b/drivers/clk/meson/meson8b.h @@ -40,6 +40,7 @@ #define HHI_VID_CLK_CNTL 0x17c /* 0x5f offset in data sheet */ #define HHI_VID_DIVIDER_CNTL 0x198 /* 0x66 offset in data sheet */ #define HHI_SYS_CPU_CLK_CNTL0 0x19c /* 0x67 offset in data sheet */ +#define HHI_NAND_CLK_CNTL 0x25c /* 0x97 offset in data sheet */ #define HHI_MPLL_CNTL 0x280 /* 0xa0 offset in data sheet */ #define HHI_SYS_PLL_CNTL 0x300 /* 0xc0 offset in data sheet */ #define HHI_VID_PLL_CNTL 0x320 /* 0xc8 offset in data sheet */ @@ -83,8 +84,10 @@ #define CLKID_FCLK_DIV4_DIV 107 #define CLKID_FCLK_DIV5_DIV 108 #define CLKID_FCLK_DIV7_DIV 109 +#define CLKID_NAND_SEL 110 +#define CLKID_NAND_DIV 111 -#define CLK_NR_CLKS 110 +#define CLK_NR_CLKS 113 /* * include the CLKID and RESETID that have |