diff options
Diffstat (limited to 'drivers/clk')
| -rw-r--r-- | drivers/clk/clk-vt8500.c | 71 |
1 files changed, 71 insertions, 0 deletions
diff --git a/drivers/clk/clk-vt8500.c b/drivers/clk/clk-vt8500.c index debf688afa8e..6d5b6e901b96 100644 --- a/drivers/clk/clk-vt8500.c +++ b/drivers/clk/clk-vt8500.c @@ -42,6 +42,7 @@ struct clk_device { #define PLL_TYPE_VT8500 0 #define PLL_TYPE_WM8650 1 #define PLL_TYPE_WM8750 2 +#define PLL_TYPE_WM8850 3 struct clk_pll { struct clk_hw hw; @@ -327,6 +328,15 @@ CLK_OF_DECLARE(vt8500_device, "via,vt8500-device-clock", vtwm_device_clk_init); #define WM8750_BITS_TO_VAL(f, m, d1, d2) \ ((f << 24) | ((m - 1) << 16) | ((d1 - 1) << 8) | d2) +/* Helper macros for PLL_WM8850 */ +#define WM8850_PLL_MUL(x) ((((x >> 16) & 0x7F) + 1) * 2) +#define WM8850_PLL_DIV(x) ((((x >> 8) & 1) + 1) * (1 << (x & 3))) + +#define WM8850_BITS_TO_FREQ(r, m, d1, d2) \ + (r * ((m + 1) * 2) / ((d1+1) * (1 << d2))) + +#define WM8850_BITS_TO_VAL(m, d1, d2) \ + ((((m / 2) - 1) << 16) | ((d1 - 1) << 8) | d2) static void vt8500_find_pll_bits(unsigned long rate, unsigned long parent_rate, u32 *multiplier, u32 *prediv) @@ -466,6 +476,49 @@ static void wm8750_find_pll_bits(unsigned long rate, unsigned long parent_rate, *divisor2 = best_div2; } +static void wm8850_find_pll_bits(unsigned long rate, unsigned long parent_rate, + u32 *multiplier, u32 *divisor1, u32 *divisor2) +{ + u32 mul, div1, div2; + u32 best_mul, best_div1, best_div2; + unsigned long tclk, rate_err, best_err; + + best_err = (unsigned long)-1; + + /* Find the closest match (lower or equal to requested) */ + for (div1 = 1; div1 >= 0; div1--) + for (div2 = 3; div2 >= 0; div2--) + for (mul = 0; mul <= 127; mul++) { + tclk = parent_rate * ((mul + 1) * 2) / + ((div1 + 1) * (1 << div2)); + if (tclk > rate) + continue; + /* error will always be +ve */ + rate_err = rate - tclk; + if (rate_err == 0) { + *multiplier = mul; + *divisor1 = div1; + *divisor2 = div2; + return; + } + + if (rate_err < best_err) { + best_err = rate_err; + best_mul = mul; + best_div1 = div1; + best_div2 = div2; + } + } + + /* if we got here, it wasn't an exact match */ + pr_warn("%s: requested rate %lu, found rate %lu\n", __func__, rate, + rate - best_err); + + *multiplier = best_mul; + *divisor1 = best_div1; + *divisor2 = best_div2; +} + static int vtwm_pll_set_rate(struct clk_hw *hw, unsigned long rate, unsigned long parent_rate) { @@ -489,6 +542,10 @@ static int vtwm_pll_set_rate(struct clk_hw *hw, unsigned long rate, wm8750_find_pll_bits(rate, parent_rate, &filter, &mul, &div1, &div2); pll_val = WM8750_BITS_TO_VAL(filter, mul, div1, div2); break; + case PLL_TYPE_WM8850: + wm8850_find_pll_bits(rate, parent_rate, &mul, &div1, &div2); + pll_val = WM8850_BITS_TO_VAL(mul, div1, div2); + break; default: pr_err("%s: invalid pll type\n", __func__); return 0; @@ -525,6 +582,10 @@ static long vtwm_pll_round_rate(struct clk_hw *hw, unsigned long rate, wm8750_find_pll_bits(rate, *prate, &filter, &mul, &div1, &div2); round_rate = WM8750_BITS_TO_FREQ(*prate, mul, div1, div2); break; + case PLL_TYPE_WM8850: + wm8850_find_pll_bits(rate, *prate, &mul, &div1, &div2); + round_rate = WM8850_BITS_TO_FREQ(*prate, mul, div1, div2); + break; default: round_rate = 0; } @@ -552,6 +613,10 @@ static unsigned long vtwm_pll_recalc_rate(struct clk_hw *hw, pll_freq = parent_rate * WM8750_PLL_MUL(pll_val); pll_freq /= WM8750_PLL_DIV(pll_val); break; + case PLL_TYPE_WM8850: + pll_freq = parent_rate * WM8850_PLL_MUL(pll_val); + pll_freq /= WM8850_PLL_DIV(pll_val); + break; default: pll_freq = 0; } @@ -628,6 +693,12 @@ static void __init wm8750_pll_init(struct device_node *node) } CLK_OF_DECLARE(wm8750_pll, "wm,wm8750-pll-clock", wm8750_pll_init); +static void __init wm8850_pll_init(struct device_node *node) +{ + vtwm_pll_clk_init(node, PLL_TYPE_WM8850); +} +CLK_OF_DECLARE(wm8850_pll, "wm,wm8850-pll-clock", wm8850_pll_init); + void __init vtwm_clk_init(void __iomem *base) { if (!base) |