Commit b8c1ddad authored by Martin Blumenstingl's avatar Martin Blumenstingl Committed by Jerome Brunet

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#L314Signed-off-by: default avatarMartin Blumenstingl <martin.blumenstingl@googlemail.com>
Signed-off-by: default avatarJerome Brunet <jbrunet@baylibre.com>
parent a0b5e4e4
...@@ -639,6 +639,54 @@ static struct clk_regmap meson8b_cpu_clk = { ...@@ -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 */ /* Everything Else (EE) domain gates */
static MESON_GATE(meson8b_ddr, HHI_GCLK_MPEG0, 0); static MESON_GATE(meson8b_ddr, HHI_GCLK_MPEG0, 0);
...@@ -834,6 +882,9 @@ static struct clk_hw_onecell_data meson8b_hw_onecell_data = { ...@@ -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_DIV4_DIV] = &meson8b_fclk_div4_div.hw,
[CLKID_FCLK_DIV5_DIV] = &meson8b_fclk_div5_div.hw, [CLKID_FCLK_DIV5_DIV] = &meson8b_fclk_div5_div.hw,
[CLKID_FCLK_DIV7_DIV] = &meson8b_fclk_div7_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, [CLK_NR_CLKS] = NULL,
}, },
.num = CLK_NR_CLKS, .num = CLK_NR_CLKS,
...@@ -939,6 +990,9 @@ static struct clk_regmap *const meson8b_clk_regmaps[] = { ...@@ -939,6 +990,9 @@ static struct clk_regmap *const meson8b_clk_regmaps[] = {
&meson8b_fclk_div4, &meson8b_fclk_div4,
&meson8b_fclk_div5, &meson8b_fclk_div5,
&meson8b_fclk_div7, &meson8b_fclk_div7,
&meson8b_nand_clk_sel,
&meson8b_nand_clk_div,
&meson8b_nand_clk_gate,
}; };
static const struct meson8b_clk_reset_line { static const struct meson8b_clk_reset_line {
......
...@@ -40,6 +40,7 @@ ...@@ -40,6 +40,7 @@
#define HHI_VID_CLK_CNTL 0x17c /* 0x5f offset in data sheet */ #define HHI_VID_CLK_CNTL 0x17c /* 0x5f offset in data sheet */
#define HHI_VID_DIVIDER_CNTL 0x198 /* 0x66 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_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_MPLL_CNTL 0x280 /* 0xa0 offset in data sheet */
#define HHI_SYS_PLL_CNTL 0x300 /* 0xc0 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 */ #define HHI_VID_PLL_CNTL 0x320 /* 0xc8 offset in data sheet */
...@@ -83,8 +84,10 @@ ...@@ -83,8 +84,10 @@
#define CLKID_FCLK_DIV4_DIV 107 #define CLKID_FCLK_DIV4_DIV 107
#define CLKID_FCLK_DIV5_DIV 108 #define CLKID_FCLK_DIV5_DIV 108
#define CLKID_FCLK_DIV7_DIV 109 #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 * include the CLKID and RESETID that have
......
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