diff options
Diffstat (limited to 'drivers/clk')
-rw-r--r-- | drivers/clk/sunxi/clk-sunxi.c | 291 |
1 files changed, 83 insertions, 208 deletions
diff --git a/drivers/clk/sunxi/clk-sunxi.c b/drivers/clk/sunxi/clk-sunxi.c index a57c36c..da15f2b 100644 --- a/drivers/clk/sunxi/clk-sunxi.c +++ b/drivers/clk/sunxi/clk-sunxi.c @@ -28,214 +28,6 @@ static DEFINE_SPINLOCK(clk_lock); -/** - * sun6i_a31_ahb1_clk_setup() - Setup function for a31 ahb1 composite clk - */ - -#define SUN6I_AHB1_MAX_PARENTS 4 -#define SUN6I_AHB1_MUX_PARENT_PLL6 3 -#define SUN6I_AHB1_MUX_SHIFT 12 -/* un-shifted mask is what mux_clk expects */ -#define SUN6I_AHB1_MUX_MASK 0x3 -#define SUN6I_AHB1_MUX_GET_PARENT(reg) ((reg >> SUN6I_AHB1_MUX_SHIFT) & \ - SUN6I_AHB1_MUX_MASK) - -#define SUN6I_AHB1_DIV_SHIFT 4 -#define SUN6I_AHB1_DIV_MASK (0x3 << SUN6I_AHB1_DIV_SHIFT) -#define SUN6I_AHB1_DIV_GET(reg) ((reg & SUN6I_AHB1_DIV_MASK) >> \ - SUN6I_AHB1_DIV_SHIFT) -#define SUN6I_AHB1_DIV_SET(reg, div) ((reg & ~SUN6I_AHB1_DIV_MASK) | \ - (div << SUN6I_AHB1_DIV_SHIFT)) -#define SUN6I_AHB1_PLL6_DIV_SHIFT 6 -#define SUN6I_AHB1_PLL6_DIV_MASK (0x3 << SUN6I_AHB1_PLL6_DIV_SHIFT) -#define SUN6I_AHB1_PLL6_DIV_GET(reg) ((reg & SUN6I_AHB1_PLL6_DIV_MASK) >> \ - SUN6I_AHB1_PLL6_DIV_SHIFT) -#define SUN6I_AHB1_PLL6_DIV_SET(reg, div) ((reg & ~SUN6I_AHB1_PLL6_DIV_MASK) | \ - (div << SUN6I_AHB1_PLL6_DIV_SHIFT)) - -struct sun6i_ahb1_clk { - struct clk_hw hw; - void __iomem *reg; -}; - -#define to_sun6i_ahb1_clk(_hw) container_of(_hw, struct sun6i_ahb1_clk, hw) - -static unsigned long sun6i_ahb1_clk_recalc_rate(struct clk_hw *hw, - unsigned long parent_rate) -{ - struct sun6i_ahb1_clk *ahb1 = to_sun6i_ahb1_clk(hw); - unsigned long rate; - u32 reg; - - /* Fetch the register value */ - reg = readl(ahb1->reg); - - /* apply pre-divider first if parent is pll6 */ - if (SUN6I_AHB1_MUX_GET_PARENT(reg) == SUN6I_AHB1_MUX_PARENT_PLL6) - parent_rate /= SUN6I_AHB1_PLL6_DIV_GET(reg) + 1; - - /* clk divider */ - rate = parent_rate >> SUN6I_AHB1_DIV_GET(reg); - - return rate; -} - -static long sun6i_ahb1_clk_round(unsigned long rate, u8 *divp, u8 *pre_divp, - u8 parent, unsigned long parent_rate) -{ - u8 div, calcp, calcm = 1; - - /* - * clock can only divide, so we will never be able to achieve - * frequencies higher than the parent frequency - */ - if (parent_rate && rate > parent_rate) - rate = parent_rate; - - div = DIV_ROUND_UP(parent_rate, rate); - - /* calculate pre-divider if parent is pll6 */ - if (parent == SUN6I_AHB1_MUX_PARENT_PLL6) { - if (div < 4) - calcp = 0; - else if (div / 2 < 4) - calcp = 1; - else if (div / 4 < 4) - calcp = 2; - else - calcp = 3; - - calcm = DIV_ROUND_UP(div, 1 << calcp); - } else { - calcp = __roundup_pow_of_two(div); - calcp = calcp > 3 ? 3 : calcp; - } - - /* we were asked to pass back divider values */ - if (divp) { - *divp = calcp; - *pre_divp = calcm - 1; - } - - return (parent_rate / calcm) >> calcp; -} - -static int sun6i_ahb1_clk_determine_rate(struct clk_hw *hw, - struct clk_rate_request *req) -{ - struct clk_hw *parent, *best_parent = NULL; - int i, num_parents; - unsigned long parent_rate, best = 0, child_rate, best_child_rate = 0; - - /* find the parent that can help provide the fastest rate <= rate */ - num_parents = clk_hw_get_num_parents(hw); - for (i = 0; i < num_parents; i++) { - parent = clk_hw_get_parent_by_index(hw, i); - if (!parent) - continue; - if (clk_hw_get_flags(hw) & CLK_SET_RATE_PARENT) - parent_rate = clk_hw_round_rate(parent, req->rate); - else - parent_rate = clk_hw_get_rate(parent); - - child_rate = sun6i_ahb1_clk_round(req->rate, NULL, NULL, i, - parent_rate); - - if (child_rate <= req->rate && child_rate > best_child_rate) { - best_parent = parent; - best = parent_rate; - best_child_rate = child_rate; - } - } - - if (!best_parent) - return -EINVAL; - - req->best_parent_hw = best_parent; - req->best_parent_rate = best; - req->rate = best_child_rate; - - return 0; -} - -static int sun6i_ahb1_clk_set_rate(struct clk_hw *hw, unsigned long rate, - unsigned long parent_rate) -{ - struct sun6i_ahb1_clk *ahb1 = to_sun6i_ahb1_clk(hw); - unsigned long flags; - u8 div, pre_div, parent; - u32 reg; - - spin_lock_irqsave(&clk_lock, flags); - - reg = readl(ahb1->reg); - - /* need to know which parent is used to apply pre-divider */ - parent = SUN6I_AHB1_MUX_GET_PARENT(reg); - sun6i_ahb1_clk_round(rate, &div, &pre_div, parent, parent_rate); - - reg = SUN6I_AHB1_DIV_SET(reg, div); - reg = SUN6I_AHB1_PLL6_DIV_SET(reg, pre_div); - writel(reg, ahb1->reg); - - spin_unlock_irqrestore(&clk_lock, flags); - - return 0; -} - -static const struct clk_ops sun6i_ahb1_clk_ops = { - .determine_rate = sun6i_ahb1_clk_determine_rate, - .recalc_rate = sun6i_ahb1_clk_recalc_rate, - .set_rate = sun6i_ahb1_clk_set_rate, -}; - -static void __init sun6i_ahb1_clk_setup(struct device_node *node) -{ - struct clk *clk; - struct sun6i_ahb1_clk *ahb1; - struct clk_mux *mux; - const char *clk_name = node->name; - const char *parents[SUN6I_AHB1_MAX_PARENTS]; - void __iomem *reg; - int i; - - reg = of_io_request_and_map(node, 0, of_node_full_name(node)); - if (IS_ERR(reg)) - return; - - /* we have a mux, we will have >1 parents */ - i = of_clk_parent_fill(node, parents, SUN6I_AHB1_MAX_PARENTS); - of_property_read_string(node, "clock-output-names", &clk_name); - - ahb1 = kzalloc(sizeof(struct sun6i_ahb1_clk), GFP_KERNEL); - if (!ahb1) - return; - - mux = kzalloc(sizeof(struct clk_mux), GFP_KERNEL); - if (!mux) { - kfree(ahb1); - return; - } - - /* set up clock properties */ - mux->reg = reg; - mux->shift = SUN6I_AHB1_MUX_SHIFT; - mux->mask = SUN6I_AHB1_MUX_MASK; - mux->lock = &clk_lock; - ahb1->reg = reg; - - clk = clk_register_composite(NULL, clk_name, parents, i, - &mux->hw, &clk_mux_ops, - &ahb1->hw, &sun6i_ahb1_clk_ops, - NULL, NULL, 0); - - if (!IS_ERR(clk)) { - of_clk_add_provider(node, of_clk_src_simple_get, clk); - clk_register_clkdev(clk, clk_name, NULL); - } -} -CLK_OF_DECLARE(sun6i_a31_ahb1, "allwinner,sun6i-a31-ahb1-clk", sun6i_ahb1_clk_setup); - /* Maximum number of parents our clocks have */ #define SUNXI_MAX_PARENTS 5 @@ -490,6 +282,68 @@ static void sun5i_a13_get_ahb_factors(struct factors_request *req) req->p = div; } +#define SUN6I_AHB1_PARENT_PLL6 3 + +/** + * sun6i_a31_get_ahb_factors() - calculates m, p factors for AHB + * AHB rate is calculated as follows + * rate = parent_rate >> p + * + * if parent is pll6, then + * parent_rate = pll6 rate / (m + 1) + */ + +static void sun6i_get_ahb1_factors(struct factors_request *req) +{ + u8 div, calcp, calcm = 1; + + /* + * clock can only divide, so we will never be able to achieve + * frequencies higher than the parent frequency + */ + if (req->parent_rate && req->rate > req->parent_rate) + req->rate = req->parent_rate; + + div = DIV_ROUND_UP(req->parent_rate, req->rate); + + /* calculate pre-divider if parent is pll6 */ + if (req->parent_index == SUN6I_AHB1_PARENT_PLL6) { + if (div < 4) + calcp = 0; + else if (div / 2 < 4) + calcp = 1; + else if (div / 4 < 4) + calcp = 2; + else + calcp = 3; + + calcm = DIV_ROUND_UP(div, 1 << calcp); + } else { + calcp = __roundup_pow_of_two(div); + calcp = calcp > 3 ? 3 : calcp; + } + + req->rate = (req->parent_rate / calcm) >> calcp; + req->p = calcp; + req->m = calcm - 1; +} + +/** + * sun6i_ahb1_recalc() - calculates AHB clock rate from m, p factors and + * parent index + */ +static void sun6i_ahb1_recalc(struct factors_request *req) +{ + req->rate = req->parent_rate; + + /* apply pre-divider first if parent is pll6 */ + if (req->parent_index == SUN6I_AHB1_PARENT_PLL6) + req->rate /= req->m + 1; + + /* clk divider */ + req->rate >>= req->p; +} + /** * sun4i_get_apb1_factors() - calculates m, p factors for APB1 * APB1 rate is calculated as follows @@ -619,6 +473,13 @@ static const struct clk_factors_config sun5i_a13_ahb_config = { .pwidth = 2, }; +static const struct clk_factors_config sun6i_ahb1_config = { + .mshift = 6, + .mwidth = 2, + .pshift = 4, + .pwidth = 2, +}; + static const struct clk_factors_config sun4i_apb1_config = { .mshift = 0, .mwidth = 5, @@ -686,6 +547,14 @@ static const struct factors_data sun5i_a13_ahb_data __initconst = { .getter = sun5i_a13_get_ahb_factors, }; +static const struct factors_data sun6i_ahb1_data __initconst = { + .mux = 12, + .muxmask = BIT(1) | BIT(0), + .table = &sun6i_ahb1_config, + .getter = sun6i_get_ahb1_factors, + .recalc = sun6i_ahb1_recalc, +}; + static const struct factors_data sun4i_apb1_data __initconst = { .mux = 24, .muxmask = BIT(1) | BIT(0), @@ -716,6 +585,12 @@ static struct clk * __init sunxi_factors_clk_setup(struct device_node *node, return sunxi_factors_register(node, data, &clk_lock, reg); } +static void __init sun6i_ahb1_clk_setup(struct device_node *node) +{ + sunxi_factors_clk_setup(node, &sun6i_ahb1_data); +} +CLK_OF_DECLARE(sun6i_a31_ahb1, "allwinner,sun6i-a31-ahb1-clk", + sun6i_ahb1_clk_setup); /** |