From cc510c736b1b278a9925a4a051ecfa72ef8c21fc Mon Sep 17 00:00:00 2001 From: Maxime Ripard Date: Wed, 1 Jul 2015 15:48:37 +0200 Subject: clk: sunxi: Add TCON channel1 clock The TCON is a controller generating the timings to output videos signals, acting like both a CRTC and an encoder. It has two channels depending on the output, each channel being driven by its own clock (and own clock controller). Add a driver for the channel 1 clock. Signed-off-by: Maxime Ripard Acked-by: Rob Herring Acked-by: Stephen Boyd --- drivers/clk/sunxi/clk-sun4i-tcon-ch1.c | 300 +++++++++++++++++++++++++++++++++ 1 file changed, 300 insertions(+) create mode 100644 drivers/clk/sunxi/clk-sun4i-tcon-ch1.c (limited to 'drivers/clk/sunxi/clk-sun4i-tcon-ch1.c') diff --git a/drivers/clk/sunxi/clk-sun4i-tcon-ch1.c b/drivers/clk/sunxi/clk-sun4i-tcon-ch1.c new file mode 100644 index 000000000000..98a4582de56a --- /dev/null +++ b/drivers/clk/sunxi/clk-sun4i-tcon-ch1.c @@ -0,0 +1,300 @@ +/* + * Copyright 2015 Maxime Ripard + * + * Maxime Ripard + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + */ + +#include +#include +#include +#include +#include + +#define TCON_CH1_SCLK2_PARENTS 4 + +#define TCON_CH1_SCLK2_GATE_BIT BIT(31) +#define TCON_CH1_SCLK2_MUX_MASK 3 +#define TCON_CH1_SCLK2_MUX_SHIFT 24 +#define TCON_CH1_SCLK2_DIV_MASK 0xf +#define TCON_CH1_SCLK2_DIV_SHIFT 0 + +#define TCON_CH1_SCLK1_GATE_BIT BIT(15) +#define TCON_CH1_SCLK1_HALF_BIT BIT(11) + +struct tcon_ch1_clk { + struct clk_hw hw; + spinlock_t lock; + void __iomem *reg; +}; + +#define hw_to_tclk(hw) container_of(hw, struct tcon_ch1_clk, hw) + +static void tcon_ch1_disable(struct clk_hw *hw) +{ + struct tcon_ch1_clk *tclk = hw_to_tclk(hw); + unsigned long flags; + u32 reg; + + spin_lock_irqsave(&tclk->lock, flags); + reg = readl(tclk->reg); + reg &= ~(TCON_CH1_SCLK2_GATE_BIT | TCON_CH1_SCLK1_GATE_BIT); + writel(reg, tclk->reg); + spin_unlock_irqrestore(&tclk->lock, flags); +} + +static int tcon_ch1_enable(struct clk_hw *hw) +{ + struct tcon_ch1_clk *tclk = hw_to_tclk(hw); + unsigned long flags; + u32 reg; + + spin_lock_irqsave(&tclk->lock, flags); + reg = readl(tclk->reg); + reg |= TCON_CH1_SCLK2_GATE_BIT | TCON_CH1_SCLK1_GATE_BIT; + writel(reg, tclk->reg); + spin_unlock_irqrestore(&tclk->lock, flags); + + return 0; +} + +static int tcon_ch1_is_enabled(struct clk_hw *hw) +{ + struct tcon_ch1_clk *tclk = hw_to_tclk(hw); + u32 reg; + + reg = readl(tclk->reg); + return reg & (TCON_CH1_SCLK2_GATE_BIT | TCON_CH1_SCLK1_GATE_BIT); +} + +static u8 tcon_ch1_get_parent(struct clk_hw *hw) +{ + struct tcon_ch1_clk *tclk = hw_to_tclk(hw); + int num_parents = clk_hw_get_num_parents(hw); + u32 reg; + + reg = readl(tclk->reg) >> TCON_CH1_SCLK2_MUX_SHIFT; + reg &= reg >> TCON_CH1_SCLK2_MUX_MASK; + + if (reg >= num_parents) + return -EINVAL; + + return reg; +} + +static int tcon_ch1_set_parent(struct clk_hw *hw, u8 index) +{ + struct tcon_ch1_clk *tclk = hw_to_tclk(hw); + unsigned long flags; + u32 reg; + + spin_lock_irqsave(&tclk->lock, flags); + reg = readl(tclk->reg); + reg &= ~(TCON_CH1_SCLK2_MUX_MASK << TCON_CH1_SCLK2_MUX_SHIFT); + reg |= index << TCON_CH1_SCLK2_MUX_SHIFT; + writel(reg, tclk->reg); + spin_unlock_irqrestore(&tclk->lock, flags); + + return 0; +}; + +static unsigned long tcon_ch1_calc_divider(unsigned long rate, + unsigned long parent_rate, + u8 *div, + bool *half) +{ + unsigned long best_rate = 0; + u8 best_m = 0, m; + bool is_double; + + for (m = 1; m < 16; m++) { + u8 d; + + for (d = 1; d < 3; d++) { + unsigned long tmp_rate; + + tmp_rate = parent_rate / m / d; + + if (tmp_rate > rate) + continue; + + if (!best_rate || + (rate - tmp_rate) < (rate - best_rate)) { + best_rate = tmp_rate; + best_m = m; + is_double = d; + } + } + } + + if (div && half) { + *div = best_m; + *half = is_double; + } + + return best_rate; +} + +static int tcon_ch1_determine_rate(struct clk_hw *hw, + struct clk_rate_request *req) +{ + long best_rate = -EINVAL; + int i; + + for (i = 0; i < clk_hw_get_num_parents(hw); i++) { + unsigned long parent_rate; + unsigned long tmp_rate; + struct clk_hw *parent; + + parent = clk_hw_get_parent_by_index(hw, i); + if (!parent) + continue; + + parent_rate = clk_hw_get_rate(parent); + + tmp_rate = tcon_ch1_calc_divider(req->rate, parent_rate, + NULL, NULL); + + if (best_rate < 0 || + (req->rate - tmp_rate) < (req->rate - best_rate)) { + best_rate = tmp_rate; + req->best_parent_rate = parent_rate; + req->best_parent_hw = parent; + } + } + + if (best_rate < 0) + return best_rate; + + req->rate = best_rate; + return 0; +} + +static unsigned long tcon_ch1_recalc_rate(struct clk_hw *hw, + unsigned long parent_rate) +{ + struct tcon_ch1_clk *tclk = hw_to_tclk(hw); + u32 reg; + + reg = readl(tclk->reg); + + parent_rate /= (reg & TCON_CH1_SCLK2_DIV_MASK) + 1; + + if (reg & TCON_CH1_SCLK1_HALF_BIT) + parent_rate /= 2; + + return parent_rate; +} + +static int tcon_ch1_set_rate(struct clk_hw *hw, unsigned long rate, + unsigned long parent_rate) +{ + struct tcon_ch1_clk *tclk = hw_to_tclk(hw); + unsigned long flags; + bool half; + u8 div_m; + u32 reg; + + tcon_ch1_calc_divider(rate, parent_rate, &div_m, &half); + + spin_lock_irqsave(&tclk->lock, flags); + reg = readl(tclk->reg); + reg &= ~(TCON_CH1_SCLK2_DIV_MASK | TCON_CH1_SCLK1_HALF_BIT); + reg |= (div_m - 1) & TCON_CH1_SCLK2_DIV_MASK; + + if (half) + reg |= TCON_CH1_SCLK1_HALF_BIT; + + writel(reg, tclk->reg); + spin_unlock_irqrestore(&tclk->lock, flags); + + return 0; +} + +static const struct clk_ops tcon_ch1_ops = { + .disable = tcon_ch1_disable, + .enable = tcon_ch1_enable, + .is_enabled = tcon_ch1_is_enabled, + + .get_parent = tcon_ch1_get_parent, + .set_parent = tcon_ch1_set_parent, + + .determine_rate = tcon_ch1_determine_rate, + .recalc_rate = tcon_ch1_recalc_rate, + .set_rate = tcon_ch1_set_rate, +}; + +static void __init tcon_ch1_setup(struct device_node *node) +{ + const char *parents[TCON_CH1_SCLK2_PARENTS]; + const char *clk_name = node->name; + struct clk_init_data init; + struct tcon_ch1_clk *tclk; + struct resource res; + struct clk *clk; + void __iomem *reg; + int ret; + + of_property_read_string(node, "clock-output-names", &clk_name); + + reg = of_io_request_and_map(node, 0, of_node_full_name(node)); + if (IS_ERR(reg)) { + pr_err("%s: Could not map the clock registers\n", clk_name); + return; + } + + ret = of_clk_parent_fill(node, parents, TCON_CH1_SCLK2_PARENTS); + if (ret != TCON_CH1_SCLK2_PARENTS) { + pr_err("%s Could not retrieve the parents\n", clk_name); + goto err_unmap; + } + + tclk = kzalloc(sizeof(*tclk), GFP_KERNEL); + if (!tclk) + goto err_unmap; + + init.name = clk_name; + init.ops = &tcon_ch1_ops; + init.parent_names = parents; + init.num_parents = TCON_CH1_SCLK2_PARENTS; + init.flags = CLK_SET_RATE_PARENT; + + tclk->reg = reg; + tclk->hw.init = &init; + spin_lock_init(&tclk->lock); + + clk = clk_register(NULL, &tclk->hw); + if (IS_ERR(clk)) { + pr_err("%s: Couldn't register the clock\n", clk_name); + goto err_free_data; + } + + ret = of_clk_add_provider(node, of_clk_src_simple_get, clk); + if (ret) { + pr_err("%s: Couldn't register our clock provider\n", clk_name); + goto err_unregister_clk; + } + + return; + +err_unregister_clk: + clk_unregister(clk); +err_free_data: + kfree(tclk); +err_unmap: + iounmap(reg); + of_address_to_resource(node, 0, &res); + release_mem_region(res.start, resource_size(&res)); +} + +CLK_OF_DECLARE(tcon_ch1, "allwinner,sun4i-a10-tcon-ch1-clk", + tcon_ch1_setup); -- cgit v1.2.3