| /* |
| * Clock driver for Keystone 2 based devices |
| * |
| * Copyright (C) 2013 Texas Instruments. |
| * Murali Karicheri <m-karicheri2@ti.com> |
| * Santosh Shilimkar <santosh.shilimkar@ti.com> |
| * |
| * 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. |
| */ |
| #include <linux/clk-provider.h> |
| #include <linux/err.h> |
| #include <linux/io.h> |
| #include <linux/slab.h> |
| #include <linux/of_address.h> |
| #include <linux/of.h> |
| #include <linux/module.h> |
| |
| /* PSC register offsets */ |
| #define PTCMD 0x120 |
| #define PTSTAT 0x128 |
| #define PDSTAT 0x200 |
| #define PDCTL 0x300 |
| #define MDSTAT 0x800 |
| #define MDCTL 0xa00 |
| |
| /* PSC module states */ |
| #define PSC_STATE_SWRSTDISABLE 0 |
| #define PSC_STATE_SYNCRST 1 |
| #define PSC_STATE_DISABLE 2 |
| #define PSC_STATE_ENABLE 3 |
| |
| #define MDSTAT_STATE_MASK 0x3f |
| #define MDSTAT_MCKOUT BIT(12) |
| #define PDSTAT_STATE_MASK 0x1f |
| #define MDCTL_FORCE BIT(31) |
| #define MDCTL_LRESET BIT(8) |
| #define PDCTL_NEXT BIT(0) |
| |
| /* Maximum timeout to bail out state transition for module */ |
| #define STATE_TRANS_MAX_COUNT 0xffff |
| |
| static void __iomem *domain_transition_base; |
| |
| /** |
| * struct clk_psc_data - PSC data |
| * @control_base: Base address for a PSC control |
| * @domain_base: Base address for a PSC domain |
| * @domain_id: PSC domain id number |
| */ |
| struct clk_psc_data { |
| void __iomem *control_base; |
| void __iomem *domain_base; |
| u32 domain_id; |
| }; |
| |
| /** |
| * struct clk_psc - PSC clock structure |
| * @hw: clk_hw for the psc |
| * @psc_data: PSC driver specific data |
| * @lock: Spinlock used by the driver |
| */ |
| struct clk_psc { |
| struct clk_hw hw; |
| struct clk_psc_data *psc_data; |
| spinlock_t *lock; |
| }; |
| |
| static DEFINE_SPINLOCK(psc_lock); |
| |
| #define to_clk_psc(_hw) container_of(_hw, struct clk_psc, hw) |
| |
| static void psc_config(void __iomem *control_base, void __iomem *domain_base, |
| u32 next_state, u32 domain_id) |
| { |
| u32 ptcmd, pdstat, pdctl, mdstat, mdctl, ptstat; |
| u32 count = STATE_TRANS_MAX_COUNT; |
| |
| mdctl = readl(control_base + MDCTL); |
| mdctl &= ~MDSTAT_STATE_MASK; |
| mdctl |= next_state; |
| /* For disable, we always put the module in local reset */ |
| if (next_state == PSC_STATE_DISABLE) |
| mdctl &= ~MDCTL_LRESET; |
| writel(mdctl, control_base + MDCTL); |
| |
| pdstat = readl(domain_base + PDSTAT); |
| if (!(pdstat & PDSTAT_STATE_MASK)) { |
| pdctl = readl(domain_base + PDCTL); |
| pdctl |= PDCTL_NEXT; |
| writel(pdctl, domain_base + PDCTL); |
| } |
| |
| ptcmd = 1 << domain_id; |
| writel(ptcmd, domain_transition_base + PTCMD); |
| do { |
| ptstat = readl(domain_transition_base + PTSTAT); |
| } while (((ptstat >> domain_id) & 1) && count--); |
| |
| count = STATE_TRANS_MAX_COUNT; |
| do { |
| mdstat = readl(control_base + MDSTAT); |
| } while (!((mdstat & MDSTAT_STATE_MASK) == next_state) && count--); |
| } |
| |
| static int keystone_clk_is_enabled(struct clk_hw *hw) |
| { |
| struct clk_psc *psc = to_clk_psc(hw); |
| struct clk_psc_data *data = psc->psc_data; |
| u32 mdstat = readl(data->control_base + MDSTAT); |
| |
| return (mdstat & MDSTAT_MCKOUT) ? 1 : 0; |
| } |
| |
| static int keystone_clk_enable(struct clk_hw *hw) |
| { |
| struct clk_psc *psc = to_clk_psc(hw); |
| struct clk_psc_data *data = psc->psc_data; |
| unsigned long flags = 0; |
| |
| if (psc->lock) |
| spin_lock_irqsave(psc->lock, flags); |
| |
| psc_config(data->control_base, data->domain_base, |
| PSC_STATE_ENABLE, data->domain_id); |
| |
| if (psc->lock) |
| spin_unlock_irqrestore(psc->lock, flags); |
| |
| return 0; |
| } |
| |
| static void keystone_clk_disable(struct clk_hw *hw) |
| { |
| struct clk_psc *psc = to_clk_psc(hw); |
| struct clk_psc_data *data = psc->psc_data; |
| unsigned long flags = 0; |
| |
| if (psc->lock) |
| spin_lock_irqsave(psc->lock, flags); |
| |
| psc_config(data->control_base, data->domain_base, |
| PSC_STATE_DISABLE, data->domain_id); |
| |
| if (psc->lock) |
| spin_unlock_irqrestore(psc->lock, flags); |
| } |
| |
| static const struct clk_ops clk_psc_ops = { |
| .enable = keystone_clk_enable, |
| .disable = keystone_clk_disable, |
| .is_enabled = keystone_clk_is_enabled, |
| }; |
| |
| /** |
| * clk_register_psc - register psc clock |
| * @dev: device that is registering this clock |
| * @name: name of this clock |
| * @parent_name: name of clock's parent |
| * @psc_data: platform data to configure this clock |
| * @lock: spinlock used by this clock |
| */ |
| static struct clk *clk_register_psc(struct device *dev, |
| const char *name, |
| const char *parent_name, |
| struct clk_psc_data *psc_data, |
| spinlock_t *lock) |
| { |
| struct clk_init_data init; |
| struct clk_psc *psc; |
| struct clk *clk; |
| |
| psc = kzalloc(sizeof(*psc), GFP_KERNEL); |
| if (!psc) |
| return ERR_PTR(-ENOMEM); |
| |
| init.name = name; |
| init.ops = &clk_psc_ops; |
| init.flags = 0; |
| init.parent_names = (parent_name ? &parent_name : NULL); |
| init.num_parents = (parent_name ? 1 : 0); |
| |
| psc->psc_data = psc_data; |
| psc->lock = lock; |
| psc->hw.init = &init; |
| |
| clk = clk_register(NULL, &psc->hw); |
| if (IS_ERR(clk)) |
| kfree(psc); |
| |
| return clk; |
| } |
| |
| /** |
| * of_psc_clk_init - initialize psc clock through DT |
| * @node: device tree node for this clock |
| * @lock: spinlock used by this clock |
| */ |
| static void __init of_psc_clk_init(struct device_node *node, spinlock_t *lock) |
| { |
| const char *clk_name = node->name; |
| const char *parent_name; |
| struct clk_psc_data *data; |
| struct clk *clk; |
| int i; |
| |
| data = kzalloc(sizeof(*data), GFP_KERNEL); |
| if (!data) { |
| pr_err("%s: Out of memory\n", __func__); |
| return; |
| } |
| |
| i = of_property_match_string(node, "reg-names", "control"); |
| data->control_base = of_iomap(node, i); |
| if (!data->control_base) { |
| pr_err("%s: control ioremap failed\n", __func__); |
| goto out; |
| } |
| |
| i = of_property_match_string(node, "reg-names", "domain"); |
| data->domain_base = of_iomap(node, i); |
| if (!data->domain_base) { |
| pr_err("%s: domain ioremap failed\n", __func__); |
| goto unmap_ctrl; |
| } |
| |
| of_property_read_u32(node, "domain-id", &data->domain_id); |
| |
| /* Domain transition registers at fixed address space of domain_id 0 */ |
| if (!domain_transition_base && !data->domain_id) |
| domain_transition_base = data->domain_base; |
| |
| of_property_read_string(node, "clock-output-names", &clk_name); |
| parent_name = of_clk_get_parent_name(node, 0); |
| if (!parent_name) { |
| pr_err("%s: Parent clock not found\n", __func__); |
| goto unmap_domain; |
| } |
| |
| clk = clk_register_psc(NULL, clk_name, parent_name, data, lock); |
| if (!IS_ERR(clk)) { |
| of_clk_add_provider(node, of_clk_src_simple_get, clk); |
| return; |
| } |
| |
| pr_err("%s: error registering clk %pOFn\n", __func__, node); |
| |
| unmap_domain: |
| iounmap(data->domain_base); |
| unmap_ctrl: |
| iounmap(data->control_base); |
| out: |
| kfree(data); |
| return; |
| } |
| |
| /** |
| * of_keystone_psc_clk_init - initialize psc clock through DT |
| * @node: device tree node for this clock |
| */ |
| static void __init of_keystone_psc_clk_init(struct device_node *node) |
| { |
| of_psc_clk_init(node, &psc_lock); |
| } |
| CLK_OF_DECLARE(keystone_gate_clk, "ti,keystone,psc-clock", |
| of_keystone_psc_clk_init); |
| |
| MODULE_LICENSE("GPL"); |
| MODULE_DESCRIPTION("Clock driver for Keystone 2 based devices"); |
| MODULE_AUTHOR("Murali Karicheri <m-karicheri2@ti.com>"); |
| MODULE_AUTHOR("Santosh Shilimkar <santosh.shilimkar@ti.com>"); |