diff options
Diffstat (limited to 'drivers/clk/clk-vt8500.c')
| -rw-r--r-- | drivers/clk/clk-vt8500.c | 102 |
1 files changed, 100 insertions, 2 deletions
diff --git a/drivers/clk/clk-vt8500.c b/drivers/clk/clk-vt8500.c index db7d41f25046..2515d4f31758 100644 --- a/drivers/clk/clk-vt8500.c +++ b/drivers/clk/clk-vt8500.c @@ -41,6 +41,7 @@ struct clk_device { #define PLL_TYPE_VT8500 0 #define PLL_TYPE_WM8650 1 +#define PLL_TYPE_WM8750 2 struct clk_pll { struct clk_hw hw; @@ -316,6 +317,16 @@ static __init void vtwm_device_clk_init(struct device_node *node) #define WM8650_BITS_TO_VAL(m, d1, d2) \ ((d2 << 13) | (d1 << 10) | (m & 0x3FF)) +/* Helper macros for PLL_WM8750 */ +#define WM8750_PLL_MUL(x) (((x >> 16) & 0xFF) + 1) +#define WM8750_PLL_DIV(x) ((((x >> 8) & 1) + 1) * (1 << (x & 7))) + +#define WM8750_BITS_TO_FREQ(r, m, d1, d2) \ + (r * (m+1) / ((d1+1) * (1 << d2))) + +#define WM8750_BITS_TO_VAL(f, m, d1, d2) \ + ((f << 24) | ((m - 1) << 16) | ((d1 - 1) << 8) | d2) + static void vt8500_find_pll_bits(unsigned long rate, unsigned long parent_rate, u32 *multiplier, u32 *prediv) @@ -384,11 +395,82 @@ static void wm8650_find_pll_bits(unsigned long rate, unsigned long parent_rate, *divisor2 = best_div2; } +static u32 wm8750_get_filter(u32 parent_rate, u32 divisor1) +{ + /* calculate frequency (MHz) after pre-divisor */ + u32 freq = (parent_rate / 1000000) / (divisor1 + 1); + + if ((freq < 10) || (freq > 200)) + pr_warn("%s: PLL recommended input frequency 10..200Mhz (requested %d Mhz)\n", + __func__, freq); + + if (freq >= 166) + return 7; + else if (freq >= 104) + return 6; + else if (freq >= 65) + return 5; + else if (freq >= 42) + return 4; + else if (freq >= 26) + return 3; + else if (freq >= 16) + return 2; + else if (freq >= 10) + return 1; + + return 0; +} + +static void wm8750_find_pll_bits(unsigned long rate, unsigned long parent_rate, + u32 *filter, 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 = 7; div2 >= 0; div2--) + for (mul = 0; mul <= 255; mul++) { + tclk = parent_rate * (mul + 1) / ((div1 + 1) * (1 << div2)); + if (tclk > rate) + continue; + /* error will always be +ve */ + rate_err = rate - tclk; + if (rate_err == 0) { + *filter = wm8750_get_filter(parent_rate, div1); + *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); + + *filter = wm8750_get_filter(parent_rate, best_div1); + *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) { struct clk_pll *pll = to_clk_pll(hw); - u32 mul, div1, div2; + u32 filter, mul, div1, div2; u32 pll_val; unsigned long flags = 0; @@ -403,6 +485,9 @@ static int vtwm_pll_set_rate(struct clk_hw *hw, unsigned long rate, wm8650_find_pll_bits(rate, parent_rate, &mul, &div1, &div2); pll_val = WM8650_BITS_TO_VAL(mul, div1, div2); break; + case PLL_TYPE_WM8750: + wm8750_find_pll_bits(rate, parent_rate, &filter, &mul, &div1, &div2); + pll_val = WM8750_BITS_TO_VAL(filter, mul, div1, div2); default: pr_err("%s: invalid pll type\n", __func__); return 0; @@ -423,7 +508,7 @@ static long vtwm_pll_round_rate(struct clk_hw *hw, unsigned long rate, unsigned long *prate) { struct clk_pll *pll = to_clk_pll(hw); - u32 mul, div1, div2; + u32 filter, mul, div1, div2; long round_rate; switch (pll->type) { @@ -435,6 +520,9 @@ static long vtwm_pll_round_rate(struct clk_hw *hw, unsigned long rate, wm8650_find_pll_bits(rate, *prate, &mul, &div1, &div2); round_rate = WM8650_BITS_TO_FREQ(*prate, mul, div1, div2); break; + case PLL_TYPE_WM8750: + wm8750_find_pll_bits(rate, *prate, &filter, &mul, &div1, &div2); + round_rate = WM8750_BITS_TO_FREQ(*prate, mul, div1, div2); default: round_rate = 0; } @@ -458,6 +546,10 @@ static unsigned long vtwm_pll_recalc_rate(struct clk_hw *hw, pll_freq = parent_rate * WM8650_PLL_MUL(pll_val); pll_freq /= WM8650_PLL_DIV(pll_val); break; + case PLL_TYPE_WM8750: + pll_freq = parent_rate * WM8750_PLL_MUL(pll_val); + pll_freq /= WM8750_PLL_DIV(pll_val); + break; default: pll_freq = 0; } @@ -526,10 +618,16 @@ static void __init wm8650_pll_init(struct device_node *node) vtwm_pll_clk_init(node, PLL_TYPE_WM8650); } +static void __init wm8750_pll_init(struct device_node *node) +{ + vtwm_pll_clk_init(node, PLL_TYPE_WM8750); +} + static const __initconst struct of_device_id clk_match[] = { { .compatible = "fixed-clock", .data = of_fixed_clk_setup, }, { .compatible = "via,vt8500-pll-clock", .data = vt8500_pll_init, }, { .compatible = "wm,wm8650-pll-clock", .data = wm8650_pll_init, }, + { .compatible = "wm,wm8750-pll-clock", .data = wm8750_pll_init, }, { .compatible = "via,vt8500-device-clock", .data = vtwm_device_clk_init, }, { /* sentinel */ } |