diff options
Diffstat (limited to 'drivers/clk/ti/apll.c')
| -rw-r--r-- | drivers/clk/ti/apll.c | 223 |
1 files changed, 223 insertions, 0 deletions
diff --git a/drivers/clk/ti/apll.c b/drivers/clk/ti/apll.c new file mode 100644 index 00000000000..b986f61f5a7 --- /dev/null +++ b/drivers/clk/ti/apll.c @@ -0,0 +1,223 @@ +/* + * OMAP APLL clock support + * + * Copyright (C) 2013 Texas Instruments, Inc. + * + * J Keerthy <j-keerthy@ti.com> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * This program is distributed "as is" WITHOUT ANY WARRANTY of any + * kind, whether express or implied; without even the implied warranty + * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + */ + +#include <linux/clk-provider.h> +#include <linux/module.h> +#include <linux/slab.h> +#include <linux/io.h> +#include <linux/err.h> +#include <linux/string.h> +#include <linux/log2.h> +#include <linux/of.h> +#include <linux/of_address.h> +#include <linux/clk/ti.h> +#include <linux/delay.h> + +#define APLL_FORCE_LOCK 0x1 +#define APLL_AUTO_IDLE 0x2 +#define MAX_APLL_WAIT_TRIES 1000000 + +#undef pr_fmt +#define pr_fmt(fmt) "%s: " fmt, __func__ + +static int dra7_apll_enable(struct clk_hw *hw) +{ + struct clk_hw_omap *clk = to_clk_hw_omap(hw); + int r = 0, i = 0; + struct dpll_data *ad; + const char *clk_name; + u8 state = 1; + u32 v; + + ad = clk->dpll_data; + if (!ad) + return -EINVAL; + + clk_name = __clk_get_name(clk->hw.clk); + + state <<= __ffs(ad->idlest_mask); + + /* Check is already locked */ + v = ti_clk_ll_ops->clk_readl(ad->idlest_reg); + + if ((v & ad->idlest_mask) == state) + return r; + + v = ti_clk_ll_ops->clk_readl(ad->control_reg); + v &= ~ad->enable_mask; + v |= APLL_FORCE_LOCK << __ffs(ad->enable_mask); + ti_clk_ll_ops->clk_writel(v, ad->control_reg); + + state <<= __ffs(ad->idlest_mask); + + while (1) { + v = ti_clk_ll_ops->clk_readl(ad->idlest_reg); + if ((v & ad->idlest_mask) == state) + break; + if (i > MAX_APLL_WAIT_TRIES) + break; + i++; + udelay(1); + } + + if (i == MAX_APLL_WAIT_TRIES) { + pr_warn("clock: %s failed transition to '%s'\n", + clk_name, (state) ? "locked" : "bypassed"); + } else { + pr_debug("clock: %s transition to '%s' in %d loops\n", + clk_name, (state) ? "locked" : "bypassed", i); + + r = 0; + } + + return r; +} + +static void dra7_apll_disable(struct clk_hw *hw) +{ + struct clk_hw_omap *clk = to_clk_hw_omap(hw); + struct dpll_data *ad; + u8 state = 1; + u32 v; + + ad = clk->dpll_data; + + state <<= __ffs(ad->idlest_mask); + + v = ti_clk_ll_ops->clk_readl(ad->control_reg); + v &= ~ad->enable_mask; + v |= APLL_AUTO_IDLE << __ffs(ad->enable_mask); + ti_clk_ll_ops->clk_writel(v, ad->control_reg); +} + +static int dra7_apll_is_enabled(struct clk_hw *hw) +{ + struct clk_hw_omap *clk = to_clk_hw_omap(hw); + struct dpll_data *ad; + u32 v; + + ad = clk->dpll_data; + + v = ti_clk_ll_ops->clk_readl(ad->control_reg); + v &= ad->enable_mask; + + v >>= __ffs(ad->enable_mask); + + return v == APLL_AUTO_IDLE ? 0 : 1; +} + +static u8 dra7_init_apll_parent(struct clk_hw *hw) +{ + return 0; +} + +static const struct clk_ops apll_ck_ops = { + .enable = &dra7_apll_enable, + .disable = &dra7_apll_disable, + .is_enabled = &dra7_apll_is_enabled, + .get_parent = &dra7_init_apll_parent, +}; + +static void __init omap_clk_register_apll(struct clk_hw *hw, + struct device_node *node) +{ + struct clk_hw_omap *clk_hw = to_clk_hw_omap(hw); + struct dpll_data *ad = clk_hw->dpll_data; + struct clk *clk; + + ad->clk_ref = of_clk_get(node, 0); + ad->clk_bypass = of_clk_get(node, 1); + + if (IS_ERR(ad->clk_ref) || IS_ERR(ad->clk_bypass)) { + pr_debug("clk-ref or clk-bypass for %s not ready, retry\n", + node->name); + if (!ti_clk_retry_init(node, hw, omap_clk_register_apll)) + return; + + goto cleanup; + } + + clk = clk_register(NULL, &clk_hw->hw); + if (!IS_ERR(clk)) { + of_clk_add_provider(node, of_clk_src_simple_get, clk); + kfree(clk_hw->hw.init->parent_names); + kfree(clk_hw->hw.init); + return; + } + +cleanup: + kfree(clk_hw->dpll_data); + kfree(clk_hw->hw.init->parent_names); + kfree(clk_hw->hw.init); + kfree(clk_hw); +} + +static void __init of_dra7_apll_setup(struct device_node *node) +{ + struct dpll_data *ad = NULL; + struct clk_hw_omap *clk_hw = NULL; + struct clk_init_data *init = NULL; + const char **parent_names = NULL; + int i; + + ad = kzalloc(sizeof(*ad), GFP_KERNEL); + clk_hw = kzalloc(sizeof(*clk_hw), GFP_KERNEL); + init = kzalloc(sizeof(*init), GFP_KERNEL); + if (!ad || !clk_hw || !init) + goto cleanup; + + clk_hw->dpll_data = ad; + clk_hw->hw.init = init; + clk_hw->flags = MEMMAP_ADDRESSING; + + init->name = node->name; + init->ops = &apll_ck_ops; + + init->num_parents = of_clk_get_parent_count(node); + if (init->num_parents < 1) { + pr_err("dra7 apll %s must have parent(s)\n", node->name); + goto cleanup; + } + + parent_names = kzalloc(sizeof(char *) * init->num_parents, GFP_KERNEL); + if (!parent_names) + goto cleanup; + + for (i = 0; i < init->num_parents; i++) + parent_names[i] = of_clk_get_parent_name(node, i); + + init->parent_names = parent_names; + + ad->control_reg = ti_clk_get_reg_addr(node, 0); + ad->idlest_reg = ti_clk_get_reg_addr(node, 1); + + if (!ad->control_reg || !ad->idlest_reg) + goto cleanup; + + ad->idlest_mask = 0x1; + ad->enable_mask = 0x3; + + omap_clk_register_apll(&clk_hw->hw, node); + return; + +cleanup: + kfree(parent_names); + kfree(ad); + kfree(clk_hw); + kfree(init); +} +CLK_OF_DECLARE(dra7_apll_clock, "ti,dra7-apll-clock", of_dra7_apll_setup); |