On Tue, 2017-10-03 at 17:25 +1030, Joel Stanley wrote: > 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 >  > --- > v4: >   - Add defines to document the BIT() macros > 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 | 177 +++++++++++++++++++++++++++++++++++++++++++++++ >  1 file changed, 177 insertions(+) >  > diff --git a/drivers/clk/clk-aspeed.c b/drivers/clk/clk-aspeed.c > index a45eb351bb05..d39cf51a5114 100644 > --- a/drivers/clk/clk-aspeed.c > +++ b/drivers/clk/clk-aspeed.c > @@ -20,7 +20,23 @@ >   >  #include >   > +#define ASPEED_RESET_CTRL 0x04 > +#define ASPEED_CLK_SELECTION 0x08 > +#define ASPEED_CLK_STOP_CTRL 0x0c > +#define ASPEED_MPLL_PARAM 0x20 > +#define ASPEED_HPLL_PARAM 0x24 > +#define  AST2500_HPLL_BYPASS_EN BIT(20) > +#define  AST2400_HPLL_STRAPPED BIT(18) > +#define  AST2400_HPLL_BYPASS_EN BIT(17) > +#define ASPEED_MISC_CTRL 0x2c > +#define  UART_DIV13_EN BIT(12) >  #define ASPEED_STRAP 0x70 > +#define  CLKIN_25MHZ_EN BIT(23) > +#define  AST2400_CLK_SOURCE_SEL BIT(18) > +#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; > @@ -98,6 +114,160 @@ 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 & AST2400_HPLL_BYPASS_EN) { > + /* 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 & AST2500_HPLL_BYPASS_EN) { > + /* 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 & CLKIN_25MHZ_EN) > + freq = 25000000; > + else if (val & AST2400_CLK_SOURCE_SEL) > + 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 & AST2400_HPLL_STRAPPED, "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 & CLKIN_25MHZ_EN) > + 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; > @@ -139,6 +309,13 @@ 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"); > + I'm still unsure about this approach with the scu compatible, but otherwise: Reviewed-by: Andrew Jeffery >   aspeed_clk_data->num = ASPEED_NUM_CLKS; >   ret = of_clk_add_hw_provider(np, of_clk_hw_onecell_get, aspeed_clk_data); >   if (ret)