2 * Clock driver for Keystone 2 based devices
4 * Copyright (C) 2013 Texas Instruments.
5 * Murali Karicheri <m-karicheri2@ti.com>
6 * Santosh Shilimkar <santosh.shilimkar@ti.com>
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 2 of the License, or
11 * (at your option) any later version.
13 #include <linux/clk-provider.h>
14 #include <linux/err.h>
16 #include <linux/slab.h>
17 #include <linux/of_address.h>
19 #include <linux/module.h>
21 /* PSC register offsets */
29 /* PSC module states */
30 #define PSC_STATE_SWRSTDISABLE 0
31 #define PSC_STATE_SYNCRST 1
32 #define PSC_STATE_DISABLE 2
33 #define PSC_STATE_ENABLE 3
35 #define MDSTAT_STATE_MASK 0x3f
36 #define MDSTAT_MCKOUT BIT(12)
37 #define PDSTAT_STATE_MASK 0x1f
38 #define MDCTL_FORCE BIT(31)
39 #define MDCTL_LRESET BIT(8)
40 #define PDCTL_NEXT BIT(0)
42 /* Maximum timeout to bail out state transition for module */
43 #define STATE_TRANS_MAX_COUNT 0xffff
45 static void __iomem *domain_transition_base;
48 * struct clk_psc_data - PSC data
49 * @control_base: Base address for a PSC control
50 * @domain_base: Base address for a PSC domain
51 * @domain_id: PSC domain id number
54 void __iomem *control_base;
55 void __iomem *domain_base;
60 * struct clk_psc - PSC clock structure
61 * @hw: clk_hw for the psc
62 * @psc_data: PSC driver specific data
63 * @lock: Spinlock used by the driver
67 struct clk_psc_data *psc_data;
71 static DEFINE_SPINLOCK(psc_lock);
73 #define to_clk_psc(_hw) container_of(_hw, struct clk_psc, hw)
75 static void psc_config(void __iomem *control_base, void __iomem *domain_base,
76 u32 next_state, u32 domain_id)
78 u32 ptcmd, pdstat, pdctl, mdstat, mdctl, ptstat;
79 u32 count = STATE_TRANS_MAX_COUNT;
81 mdctl = readl(control_base + MDCTL);
82 mdctl &= ~MDSTAT_STATE_MASK;
84 /* For disable, we always put the module in local reset */
85 if (next_state == PSC_STATE_DISABLE)
86 mdctl &= ~MDCTL_LRESET;
87 writel(mdctl, control_base + MDCTL);
89 pdstat = readl(domain_base + PDSTAT);
90 if (!(pdstat & PDSTAT_STATE_MASK)) {
91 pdctl = readl(domain_base + PDCTL);
93 writel(pdctl, domain_base + PDCTL);
96 ptcmd = 1 << domain_id;
97 writel(ptcmd, domain_transition_base + PTCMD);
99 ptstat = readl(domain_transition_base + PTSTAT);
100 } while (((ptstat >> domain_id) & 1) && count--);
102 count = STATE_TRANS_MAX_COUNT;
104 mdstat = readl(control_base + MDSTAT);
105 } while (!((mdstat & MDSTAT_STATE_MASK) == next_state) && count--);
108 static int keystone_clk_is_enabled(struct clk_hw *hw)
110 struct clk_psc *psc = to_clk_psc(hw);
111 struct clk_psc_data *data = psc->psc_data;
112 u32 mdstat = readl(data->control_base + MDSTAT);
114 return (mdstat & MDSTAT_MCKOUT) ? 1 : 0;
117 static int keystone_clk_enable(struct clk_hw *hw)
119 struct clk_psc *psc = to_clk_psc(hw);
120 struct clk_psc_data *data = psc->psc_data;
121 unsigned long flags = 0;
124 spin_lock_irqsave(psc->lock, flags);
126 psc_config(data->control_base, data->domain_base,
127 PSC_STATE_ENABLE, data->domain_id);
130 spin_unlock_irqrestore(psc->lock, flags);
135 static void keystone_clk_disable(struct clk_hw *hw)
137 struct clk_psc *psc = to_clk_psc(hw);
138 struct clk_psc_data *data = psc->psc_data;
139 unsigned long flags = 0;
142 spin_lock_irqsave(psc->lock, flags);
144 psc_config(data->control_base, data->domain_base,
145 PSC_STATE_DISABLE, data->domain_id);
148 spin_unlock_irqrestore(psc->lock, flags);
151 static const struct clk_ops clk_psc_ops = {
152 .enable = keystone_clk_enable,
153 .disable = keystone_clk_disable,
154 .is_enabled = keystone_clk_is_enabled,
158 * clk_register_psc - register psc clock
159 * @dev: device that is registering this clock
160 * @name: name of this clock
161 * @parent_name: name of clock's parent
162 * @psc_data: platform data to configure this clock
163 * @lock: spinlock used by this clock
165 static struct clk *clk_register_psc(struct device *dev,
167 const char *parent_name,
168 struct clk_psc_data *psc_data,
171 struct clk_init_data init;
175 psc = kzalloc(sizeof(*psc), GFP_KERNEL);
177 return ERR_PTR(-ENOMEM);
180 init.ops = &clk_psc_ops;
182 init.parent_names = (parent_name ? &parent_name : NULL);
183 init.num_parents = (parent_name ? 1 : 0);
185 psc->psc_data = psc_data;
187 psc->hw.init = &init;
189 clk = clk_register(NULL, &psc->hw);
197 * of_psc_clk_init - initialize psc clock through DT
198 * @node: device tree node for this clock
199 * @lock: spinlock used by this clock
201 static void __init of_psc_clk_init(struct device_node *node, spinlock_t *lock)
203 const char *clk_name = node->name;
204 const char *parent_name;
205 struct clk_psc_data *data;
209 data = kzalloc(sizeof(*data), GFP_KERNEL);
211 pr_err("%s: Out of memory\n", __func__);
215 i = of_property_match_string(node, "reg-names", "control");
216 data->control_base = of_iomap(node, i);
217 if (!data->control_base) {
218 pr_err("%s: control ioremap failed\n", __func__);
222 i = of_property_match_string(node, "reg-names", "domain");
223 data->domain_base = of_iomap(node, i);
224 if (!data->domain_base) {
225 pr_err("%s: domain ioremap failed\n", __func__);
229 of_property_read_u32(node, "domain-id", &data->domain_id);
231 /* Domain transition registers at fixed address space of domain_id 0 */
232 if (!domain_transition_base && !data->domain_id)
233 domain_transition_base = data->domain_base;
235 of_property_read_string(node, "clock-output-names", &clk_name);
236 parent_name = of_clk_get_parent_name(node, 0);
238 pr_err("%s: Parent clock not found\n", __func__);
242 clk = clk_register_psc(NULL, clk_name, parent_name, data, lock);
244 of_clk_add_provider(node, of_clk_src_simple_get, clk);
248 pr_err("%s: error registering clk %s\n", __func__, node->name);
251 iounmap(data->domain_base);
253 iounmap(data->control_base);
260 * of_keystone_psc_clk_init - initialize psc clock through DT
261 * @node: device tree node for this clock
263 static void __init of_keystone_psc_clk_init(struct device_node *node)
265 of_psc_clk_init(node, &psc_lock);
267 CLK_OF_DECLARE(keystone_gate_clk, "ti,keystone,psc-clock",
268 of_keystone_psc_clk_init);