Messages in this thread Patch in this message | | | From | Joel Stanley <> | Subject | [PATCH v3 2/5] clk: aspeed: Register core clocks | Date | Wed, 27 Sep 2017 15:56:59 +0930 |
| |
This registers the core clocks; those which are required to calculate the rate of the timer peripheral so the system can load a clocksource driver.
Signed-off-by: Joel Stanley <joel@jms.id.au>
--- v3: - Fix ast2400 ahb calculation - Remove incorrect 'this is wrong' comment - Separate out clkin calc to be per platform - Support 48MHz clkin on ast2400 --- drivers/clk/clk-aspeed.c | 164 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 164 insertions(+)
diff --git a/drivers/clk/clk-aspeed.c b/drivers/clk/clk-aspeed.c index 36b79a378f73..14387055554f 100644 --- a/drivers/clk/clk-aspeed.c +++ b/drivers/clk/clk-aspeed.c @@ -29,6 +29,9 @@ #define ASPEED_STRAP 0x70 #define ASPEED_CLK_SELECTION_2 0xd8 +/* Globally visible clocks */ +static DEFINE_SPINLOCK(aspeed_clk_lock); + /* Keeps track of all clocks */ static struct clk_hw_onecell_data *aspeed_clk_data; @@ -105,6 +108,160 @@ static const struct aspeed_gate_data aspeed_gates[] __initconst = { [ASPEED_CLK_GATE_LHCCLK] = { 28, -1, "lhclk-gate", "lhclk", 0 }, /* LPC master/LPC+ */ }; +static const struct clk_div_table ast2400_div_table[] = { + { 0x0, 2 }, + { 0x1, 4 }, + { 0x2, 6 }, + { 0x3, 8 }, + { 0x4, 10 }, + { 0x5, 12 }, + { 0x6, 14 }, + { 0x7, 16 }, + { 0 } +}; + +static const struct clk_div_table ast2500_div_table[] = { + { 0x0, 4 }, + { 0x1, 8 }, + { 0x2, 12 }, + { 0x3, 16 }, + { 0x4, 20 }, + { 0x5, 24 }, + { 0x6, 28 }, + { 0x7, 32 }, + { 0 } +}; + +static struct clk_hw *aspeed_ast2400_calc_pll(const char *name, u32 val) +{ + unsigned int mult, div; + + if (val & BIT(17)) { + /* Pass through mode */ + mult = div = 1; + } else { + /* F = 24Mhz * (2-OD) * [(N + 2) / (D + 1)] */ + u32 n = (val >> 5) & 0x3f; + u32 od = (val >> 4) & 0x1; + u32 d = val & 0xf; + + mult = (2 - od) * (n + 2); + div = d + 1; + } + return clk_hw_register_fixed_factor(NULL, name, "clkin", 0, + mult, div); +}; + +static struct clk_hw *aspeed_ast2500_calc_pll(const char *name, u32 val) +{ + unsigned int mult, div; + + if (val & BIT(20)) { + /* Pass through mode */ + mult = div = 1; + } else { + /* F = clkin * [(M+1) / (N+1)] / (P + 1) */ + u32 p = (val >> 13) & 0x3f; + u32 m = (val >> 5) & 0xff; + u32 n = val & 0x1f; + + mult = (m + 1) / (n + 1); + div = p + 1; + } + + return clk_hw_register_fixed_factor(NULL, name, "clkin", 0, + mult, div); +} + +static void __init aspeed_ast2400_cc(struct regmap *map) +{ + struct clk_hw *hw; + u32 val, freq, div; + + /* + * CLKIN is the crystal oscillator, 24, 48 or 25MHz selected by + * strapping + */ + regmap_read(map, ASPEED_STRAP, &val); + if (val & BIT(23)) + freq = 25000000; + else if (val & BIT(18)) + freq = 48000000; + else + freq = 24000000; + hw = clk_hw_register_fixed_rate(NULL, "clkin", NULL, 0, freq); + pr_debug("clkin @%u MHz\n", freq / 1000000); + + /* + * High-speed PLL clock derived from the crystal. This the CPU clock, + * and we assume that it is enabled + */ + regmap_read(map, ASPEED_HPLL_PARAM, &val); + WARN(val & BIT(18), "hpll is strapped not configured"); + aspeed_clk_data->hws[ASPEED_CLK_HPLL] = aspeed_ast2400_calc_pll("hpll", val); + + /* + * Strap bits 11:10 define the CPU/AHB clock frequency ratio (aka HCLK) + * 00: Select CPU:AHB = 1:1 + * 01: Select CPU:AHB = 2:1 + * 10: Select CPU:AHB = 4:1 + * 11: Select CPU:AHB = 3:1 + */ + regmap_read(map, ASPEED_STRAP, &val); + val = (val >> 10) & 0x3; + div = val + 1; + if (div == 3) + div = 4; + else if (div == 4) + div = 3; + hw = clk_hw_register_fixed_factor(NULL, "ahb", "hpll", 0, 1, div); + aspeed_clk_data->hws[ASPEED_CLK_AHB] = hw; + + /* APB clock clock selection register SCU08 (aka PCLK) */ + hw = clk_hw_register_divider_table(NULL, "apb", "hpll", 0, + scu_base + ASPEED_CLK_SELECTION, 23, 3, 0, + ast2400_div_table, + &aspeed_clk_lock); + aspeed_clk_data->hws[ASPEED_CLK_APB] = hw; +} + +static void __init aspeed_ast2500_cc(struct regmap *map) +{ + struct clk_hw *hw; + u32 val, freq, div; + + /* CLKIN is the crystal oscillator, 24 or 25MHz selected by strapping */ + regmap_read(map, ASPEED_STRAP, &val); + if (val & BIT(23)) + freq = 25000000; + else + freq = 24000000; + hw = clk_hw_register_fixed_rate(NULL, "clkin", NULL, 0, freq); + pr_debug("clkin @%u MHz\n", freq / 1000000); + + /* + * High-speed PLL clock derived from the crystal. This the CPU clock, + * and we assume that it is enabled + */ + regmap_read(map, ASPEED_HPLL_PARAM, &val); + aspeed_clk_data->hws[ASPEED_CLK_HPLL] = aspeed_ast2500_calc_pll("hpll", val); + + /* Strap bits 11:9 define the AXI/AHB clock frequency ratio (aka HCLK)*/ + regmap_read(map, ASPEED_STRAP, &val); + val = (val >> 9) & 0x7; + WARN(val == 0, "strapping is zero: cannot determine ahb clock"); + div = 2 * (val + 1); + hw = clk_hw_register_fixed_factor(NULL, "ahb", "hpll", 0, 1, div); + aspeed_clk_data->hws[ASPEED_CLK_AHB] = hw; + + /* APB clock clock selection register SCU08 (aka PCLK) */ + regmap_read(map, ASPEED_CLK_SELECTION, &val); + val = (val >> 23) & 0x7; + div = 4 * (val + 1); + hw = clk_hw_register_fixed_factor(NULL, "apb", "hpll", 0, 1, div); + aspeed_clk_data->hws[ASPEED_CLK_APB] = hw; +}; + static void __init aspeed_cc_init(struct device_node *np) { struct regmap *map; @@ -146,6 +303,13 @@ static void __init aspeed_cc_init(struct device_node *np) return; } + if (of_device_is_compatible(np, "aspeed,ast2400-scu")) + aspeed_ast2400_cc(map); + else if (of_device_is_compatible(np, "aspeed,ast2500-scu")) + aspeed_ast2500_cc(map); + else + pr_err("unknown platform, failed to add clocks\n"); + aspeed_clk_data->num = ASPEED_NUM_CLKS; ret = of_clk_add_hw_provider(np, of_clk_hw_onecell_get, aspeed_clk_data); if (ret) -- 2.14.1
| |