From 3ca2377b6fed7c3db0c064ea73327cc6895e175d Mon Sep 17 00:00:00 2001 From: Chen-Yu Tsai Date: Mon, 25 Jan 2016 21:15:46 +0800 Subject: clk: sunxi: rewrite sun6i-ar100 using factors clk sun6i's AR100 clock is a classic factors clk case: AR100 = ((parent mux) >> p) / (m + 1) Signed-off-by: Chen-Yu Tsai Signed-off-by: Maxime Ripard --- drivers/clk/sunxi/clk-sun6i-ar100.c | 235 ++++++++++-------------------------- 1 file changed, 61 insertions(+), 174 deletions(-) (limited to 'drivers/clk') diff --git a/drivers/clk/sunxi/clk-sun6i-ar100.c b/drivers/clk/sunxi/clk-sun6i-ar100.c index 2088768..a7f5777 100644 --- a/drivers/clk/sunxi/clk-sun6i-ar100.c +++ b/drivers/clk/sunxi/clk-sun6i-ar100.c @@ -8,211 +8,97 @@ * */ +#include #include #include #include #include +#include -#define SUN6I_AR100_MAX_PARENTS 4 -#define SUN6I_AR100_SHIFT_MASK 0x3 -#define SUN6I_AR100_SHIFT_MAX SUN6I_AR100_SHIFT_MASK -#define SUN6I_AR100_SHIFT_SHIFT 4 -#define SUN6I_AR100_DIV_MASK 0x1f -#define SUN6I_AR100_DIV_MAX (SUN6I_AR100_DIV_MASK + 1) -#define SUN6I_AR100_DIV_SHIFT 8 -#define SUN6I_AR100_MUX_MASK 0x3 -#define SUN6I_AR100_MUX_SHIFT 16 - -struct ar100_clk { - struct clk_hw hw; - void __iomem *reg; -}; - -static inline struct ar100_clk *to_ar100_clk(struct clk_hw *hw) -{ - return container_of(hw, struct ar100_clk, hw); -} - -static unsigned long ar100_recalc_rate(struct clk_hw *hw, - unsigned long parent_rate) -{ - struct ar100_clk *clk = to_ar100_clk(hw); - u32 val = readl(clk->reg); - int shift = (val >> SUN6I_AR100_SHIFT_SHIFT) & SUN6I_AR100_SHIFT_MASK; - int div = (val >> SUN6I_AR100_DIV_SHIFT) & SUN6I_AR100_DIV_MASK; - - return (parent_rate >> shift) / (div + 1); -} - -static int ar100_determine_rate(struct clk_hw *hw, - struct clk_rate_request *req) -{ - int nparents = clk_hw_get_num_parents(hw); - long best_rate = -EINVAL; - int i; - - req->best_parent_hw = NULL; - - for (i = 0; i < nparents; i++) { - unsigned long parent_rate; - unsigned long tmp_rate; - struct clk_hw *parent; - unsigned long div; - int shift; - - parent = clk_hw_get_parent_by_index(hw, i); - parent_rate = clk_hw_get_rate(parent); - div = DIV_ROUND_UP(parent_rate, req->rate); - - /* - * The AR100 clk contains 2 divisors: - * - one power of 2 divisor - * - one regular divisor - * - * First check if we can safely shift (or divide by a power - * of 2) without losing precision on the requested rate. - */ - shift = ffs(div) - 1; - if (shift > SUN6I_AR100_SHIFT_MAX) - shift = SUN6I_AR100_SHIFT_MAX; - - div >>= shift; - - /* - * Then if the divisor is still bigger than what the HW - * actually supports, use a bigger shift (or power of 2 - * divider) value and accept to lose some precision. - */ - while (div > SUN6I_AR100_DIV_MAX) { - shift++; - div >>= 1; - if (shift > SUN6I_AR100_SHIFT_MAX) - break; - } - - /* - * If the shift value (or power of 2 divider) is bigger - * than what the HW actually support, skip this parent. - */ - if (shift > SUN6I_AR100_SHIFT_MAX) - continue; - - tmp_rate = (parent_rate >> shift) / div; - if (!req->best_parent_hw || tmp_rate > best_rate) { - req->best_parent_hw = parent; - req->best_parent_rate = parent_rate; - best_rate = tmp_rate; - } - } - - if (best_rate < 0) - return best_rate; - - req->rate = best_rate; - - return 0; -} - -static int ar100_set_parent(struct clk_hw *hw, u8 index) -{ - struct ar100_clk *clk = to_ar100_clk(hw); - u32 val = readl(clk->reg); - - if (index >= SUN6I_AR100_MAX_PARENTS) - return -EINVAL; - - val &= ~(SUN6I_AR100_MUX_MASK << SUN6I_AR100_MUX_SHIFT); - val |= (index << SUN6I_AR100_MUX_SHIFT); - writel(val, clk->reg); - - return 0; -} +#include "clk-factors.h" -static u8 ar100_get_parent(struct clk_hw *hw) -{ - struct ar100_clk *clk = to_ar100_clk(hw); - return (readl(clk->reg) >> SUN6I_AR100_MUX_SHIFT) & - SUN6I_AR100_MUX_MASK; -} - -static int ar100_set_rate(struct clk_hw *hw, unsigned long rate, - unsigned long parent_rate) +/** + * sun6i_get_ar100_factors - Calculates factors p, m for AR100 + * + * AR100 rate is calculated as follows + * rate = (parent_rate >> p) / (m + 1); + */ +static void sun6i_get_ar100_factors(struct factors_request *req) { - unsigned long div = parent_rate / rate; - struct ar100_clk *clk = to_ar100_clk(hw); - u32 val = readl(clk->reg); + unsigned long div; int shift; - if (parent_rate % rate) - return -EINVAL; + /* clock only divides */ + if (req->rate > req->parent_rate) + req->rate = req->parent_rate; - shift = ffs(div) - 1; - if (shift > SUN6I_AR100_SHIFT_MAX) - shift = SUN6I_AR100_SHIFT_MAX; + div = DIV_ROUND_UP(req->parent_rate, req->rate); - div >>= shift; + if (div < 32) + shift = 0; + else if (div >> 1 < 32) + shift = 1; + else if (div >> 2 < 32) + shift = 2; + else + shift = 3; - if (div > SUN6I_AR100_DIV_MAX) - return -EINVAL; + div >>= shift; - val &= ~((SUN6I_AR100_SHIFT_MASK << SUN6I_AR100_SHIFT_SHIFT) | - (SUN6I_AR100_DIV_MASK << SUN6I_AR100_DIV_SHIFT)); - val |= (shift << SUN6I_AR100_SHIFT_SHIFT) | - (div << SUN6I_AR100_DIV_SHIFT); - writel(val, clk->reg); + if (div > 32) + div = 32; - return 0; + req->rate = (req->parent_rate >> shift) / div; + req->m = div - 1; + req->p = shift; } -static struct clk_ops ar100_ops = { - .recalc_rate = ar100_recalc_rate, - .determine_rate = ar100_determine_rate, - .set_parent = ar100_set_parent, - .get_parent = ar100_get_parent, - .set_rate = ar100_set_rate, +static const struct clk_factors_config sun6i_ar100_config = { + .mwidth = 5, + .mshift = 8, + .pwidth = 2, + .pshift = 4, }; +static const struct factors_data sun6i_ar100_data __initconst = { + .mux = 16, + .muxmask = GENMASK(1, 0), + .table = &sun6i_ar100_config, + .getter = sun6i_get_ar100_factors, +}; + +static DEFINE_SPINLOCK(sun6i_ar100_lock); + static int sun6i_a31_ar100_clk_probe(struct platform_device *pdev) { - const char *parents[SUN6I_AR100_MAX_PARENTS]; struct device_node *np = pdev->dev.of_node; - const char *clk_name = np->name; - struct clk_init_data init; - struct ar100_clk *ar100; struct resource *r; + void __iomem *reg; struct clk *clk; - int nparents; - - ar100 = devm_kzalloc(&pdev->dev, sizeof(*ar100), GFP_KERNEL); - if (!ar100) - return -ENOMEM; r = platform_get_resource(pdev, IORESOURCE_MEM, 0); - ar100->reg = devm_ioremap_resource(&pdev->dev, r); - if (IS_ERR(ar100->reg)) - return PTR_ERR(ar100->reg); + reg = devm_ioremap_resource(&pdev->dev, r); + if (IS_ERR(reg)) + return PTR_ERR(reg); - nparents = of_clk_get_parent_count(np); - if (nparents > SUN6I_AR100_MAX_PARENTS) - nparents = SUN6I_AR100_MAX_PARENTS; - - of_clk_parent_fill(np, parents, nparents); + clk = sunxi_factors_register(np, &sun6i_ar100_data, &sun6i_ar100_lock, + reg); + if (!clk) + return -ENOMEM; - of_property_read_string(np, "clock-output-names", &clk_name); + platform_set_drvdata(pdev, clk); - init.name = clk_name; - init.ops = &ar100_ops; - init.parent_names = parents; - init.num_parents = nparents; - init.flags = 0; + return 0; +} - ar100->hw.init = &init; +static int sun6i_a31_ar100_clk_remove(struct platform_device *pdev) +{ + struct device_node *np = pdev->dev.of_node; + struct clk *clk = platform_get_drvdata(pdev); - clk = clk_register(&pdev->dev, &ar100->hw); - if (IS_ERR(clk)) - return PTR_ERR(clk); + sunxi_factors_unregister(np, clk); - return of_clk_add_provider(np, of_clk_src_simple_get, clk); + return 0; } static const struct of_device_id sun6i_a31_ar100_clk_dt_ids[] = { @@ -227,6 +113,7 @@ static struct platform_driver sun6i_a31_ar100_clk_driver = { .of_match_table = sun6i_a31_ar100_clk_dt_ids, }, .probe = sun6i_a31_ar100_clk_probe, + .remove = sun6i_a31_ar100_clk_remove, }; module_platform_driver(sun6i_a31_ar100_clk_driver); -- cgit v1.1