2 * Intel Atom platform clocks driver for BayTrail and CherryTrail SoCs
4 * Copyright (C) 2016, Intel Corporation
5 * Author: Irina Tirdea <irina.tirdea@intel.com>
7 * This program is free software; you can redistribute it and/or modify it
8 * under the terms and conditions of the GNU General Public License,
9 * version 2, as published by the Free Software Foundation.
11 * This program is distributed in the hope it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
17 #include <linux/clk-provider.h>
18 #include <linux/clkdev.h>
19 #include <linux/err.h>
20 #include <linux/platform_data/x86/clk-pmc-atom.h>
21 #include <linux/platform_device.h>
22 #include <linux/slab.h>
24 #define PLT_CLK_NAME_BASE "pmc_plt_clk"
26 #define PMC_CLK_CTL_OFFSET 0x60
27 #define PMC_CLK_CTL_SIZE 4
29 #define PMC_CLK_CTL_GATED_ON_D3 0x0
30 #define PMC_CLK_CTL_FORCE_ON 0x1
31 #define PMC_CLK_CTL_FORCE_OFF 0x2
32 #define PMC_CLK_CTL_RESERVED 0x3
33 #define PMC_MASK_CLK_CTL GENMASK(1, 0)
34 #define PMC_MASK_CLK_FREQ BIT(2)
35 #define PMC_CLK_FREQ_XTAL (0 << 2) /* 25 MHz */
36 #define PMC_CLK_FREQ_PLL (1 << 2) /* 19.2 MHz */
38 struct clk_plt_fixed
{
40 struct clk_lookup
*lookup
;
46 struct clk_lookup
*lookup
;
47 /* protect access to PMC registers */
51 #define to_clk_plt(_hw) container_of(_hw, struct clk_plt, hw)
54 struct clk_plt_fixed
**parents
;
56 struct clk_plt
*clks
[PMC_CLK_NUM
];
59 /* Return an index in parent table */
60 static inline int plt_reg_to_parent(int reg
)
62 switch (reg
& PMC_MASK_CLK_FREQ
) {
64 case PMC_CLK_FREQ_XTAL
:
66 case PMC_CLK_FREQ_PLL
:
71 /* Return clk index of parent */
72 static inline int plt_parent_to_reg(int index
)
77 return PMC_CLK_FREQ_XTAL
;
79 return PMC_CLK_FREQ_PLL
;
83 /* Abstract status in simpler enabled/disabled value */
84 static inline int plt_reg_to_enabled(int reg
)
86 switch (reg
& PMC_MASK_CLK_CTL
) {
87 case PMC_CLK_CTL_GATED_ON_D3
:
88 case PMC_CLK_CTL_FORCE_ON
:
89 return 1; /* enabled */
90 case PMC_CLK_CTL_FORCE_OFF
:
91 case PMC_CLK_CTL_RESERVED
:
93 return 0; /* disabled */
97 static void plt_clk_reg_update(struct clk_plt
*clk
, u32 mask
, u32 val
)
102 spin_lock_irqsave(&clk
->lock
, flags
);
104 tmp
= readl(clk
->reg
);
105 tmp
= (tmp
& ~mask
) | (val
& mask
);
106 writel(tmp
, clk
->reg
);
108 spin_unlock_irqrestore(&clk
->lock
, flags
);
111 static int plt_clk_set_parent(struct clk_hw
*hw
, u8 index
)
113 struct clk_plt
*clk
= to_clk_plt(hw
);
115 plt_clk_reg_update(clk
, PMC_MASK_CLK_FREQ
, plt_parent_to_reg(index
));
120 static u8
plt_clk_get_parent(struct clk_hw
*hw
)
122 struct clk_plt
*clk
= to_clk_plt(hw
);
125 value
= readl(clk
->reg
);
127 return plt_reg_to_parent(value
);
130 static int plt_clk_enable(struct clk_hw
*hw
)
132 struct clk_plt
*clk
= to_clk_plt(hw
);
134 plt_clk_reg_update(clk
, PMC_MASK_CLK_CTL
, PMC_CLK_CTL_FORCE_ON
);
139 static void plt_clk_disable(struct clk_hw
*hw
)
141 struct clk_plt
*clk
= to_clk_plt(hw
);
143 plt_clk_reg_update(clk
, PMC_MASK_CLK_CTL
, PMC_CLK_CTL_FORCE_OFF
);
146 static int plt_clk_is_enabled(struct clk_hw
*hw
)
148 struct clk_plt
*clk
= to_clk_plt(hw
);
151 value
= readl(clk
->reg
);
153 return plt_reg_to_enabled(value
);
156 static const struct clk_ops plt_clk_ops
= {
157 .enable
= plt_clk_enable
,
158 .disable
= plt_clk_disable
,
159 .is_enabled
= plt_clk_is_enabled
,
160 .get_parent
= plt_clk_get_parent
,
161 .set_parent
= plt_clk_set_parent
,
162 .determine_rate
= __clk_mux_determine_rate
,
165 static struct clk_plt
*plt_clk_register(struct platform_device
*pdev
, int id
,
167 const char **parent_names
,
170 struct clk_plt
*pclk
;
171 struct clk_init_data init
;
174 pclk
= devm_kzalloc(&pdev
->dev
, sizeof(*pclk
), GFP_KERNEL
);
176 return ERR_PTR(-ENOMEM
);
178 init
.name
= kasprintf(GFP_KERNEL
, "%s_%d", PLT_CLK_NAME_BASE
, id
);
179 init
.ops
= &plt_clk_ops
;
181 init
.parent_names
= parent_names
;
182 init
.num_parents
= num_parents
;
184 pclk
->hw
.init
= &init
;
185 pclk
->reg
= base
+ PMC_CLK_CTL_OFFSET
+ id
* PMC_CLK_CTL_SIZE
;
186 spin_lock_init(&pclk
->lock
);
188 ret
= devm_clk_hw_register(&pdev
->dev
, &pclk
->hw
);
194 pclk
->lookup
= clkdev_hw_create(&pclk
->hw
, init
.name
, NULL
);
196 pclk
= ERR_PTR(-ENOMEM
);
205 static void plt_clk_unregister(struct clk_plt
*pclk
)
207 clkdev_drop(pclk
->lookup
);
210 static struct clk_plt_fixed
*plt_clk_register_fixed_rate(struct platform_device
*pdev
,
212 const char *parent_name
,
213 unsigned long fixed_rate
)
215 struct clk_plt_fixed
*pclk
;
217 pclk
= devm_kzalloc(&pdev
->dev
, sizeof(*pclk
), GFP_KERNEL
);
219 return ERR_PTR(-ENOMEM
);
221 pclk
->clk
= clk_hw_register_fixed_rate(&pdev
->dev
, name
, parent_name
,
223 if (IS_ERR(pclk
->clk
))
224 return ERR_CAST(pclk
->clk
);
226 pclk
->lookup
= clkdev_hw_create(pclk
->clk
, name
, NULL
);
228 clk_hw_unregister_fixed_rate(pclk
->clk
);
229 return ERR_PTR(-ENOMEM
);
235 static void plt_clk_unregister_fixed_rate(struct clk_plt_fixed
*pclk
)
237 clkdev_drop(pclk
->lookup
);
238 clk_hw_unregister_fixed_rate(pclk
->clk
);
241 static void plt_clk_unregister_fixed_rate_loop(struct clk_plt_data
*data
,
245 plt_clk_unregister_fixed_rate(data
->parents
[i
]);
248 static void plt_clk_free_parent_names_loop(const char **parent_names
,
252 kfree_const(parent_names
[i
]);
256 static void plt_clk_unregister_loop(struct clk_plt_data
*data
,
260 plt_clk_unregister(data
->clks
[i
]);
263 static const char **plt_clk_register_parents(struct platform_device
*pdev
,
264 struct clk_plt_data
*data
,
265 const struct pmc_clk
*clks
)
267 const char **parent_names
;
273 while (clks
[nparents
].name
)
276 data
->parents
= devm_kcalloc(&pdev
->dev
, nparents
,
277 sizeof(*data
->parents
), GFP_KERNEL
);
279 return ERR_PTR(-ENOMEM
);
281 parent_names
= kcalloc(nparents
, sizeof(*parent_names
),
284 return ERR_PTR(-ENOMEM
);
286 for (i
= 0; i
< nparents
; i
++) {
288 plt_clk_register_fixed_rate(pdev
, clks
[i
].name
,
291 if (IS_ERR(data
->parents
[i
])) {
292 err
= PTR_ERR(data
->parents
[i
]);
295 parent_names
[i
] = kstrdup_const(clks
[i
].name
, GFP_KERNEL
);
298 data
->nparents
= nparents
;
302 plt_clk_unregister_fixed_rate_loop(data
, i
);
303 plt_clk_free_parent_names_loop(parent_names
, i
);
307 static void plt_clk_unregister_parents(struct clk_plt_data
*data
)
309 plt_clk_unregister_fixed_rate_loop(data
, data
->nparents
);
312 static int plt_clk_probe(struct platform_device
*pdev
)
314 const struct pmc_clk_data
*pmc_data
;
315 const char **parent_names
;
316 struct clk_plt_data
*data
;
320 pmc_data
= dev_get_platdata(&pdev
->dev
);
321 if (!pmc_data
|| !pmc_data
->clks
)
324 data
= devm_kzalloc(&pdev
->dev
, sizeof(*data
), GFP_KERNEL
);
328 parent_names
= plt_clk_register_parents(pdev
, data
, pmc_data
->clks
);
329 if (IS_ERR(parent_names
))
330 return PTR_ERR(parent_names
);
332 for (i
= 0; i
< PMC_CLK_NUM
; i
++) {
333 data
->clks
[i
] = plt_clk_register(pdev
, i
, pmc_data
->base
,
334 parent_names
, data
->nparents
);
335 if (IS_ERR(data
->clks
[i
])) {
336 err
= PTR_ERR(data
->clks
[i
]);
337 goto err_unreg_clk_plt
;
341 plt_clk_free_parent_names_loop(parent_names
, data
->nparents
);
343 platform_set_drvdata(pdev
, data
);
347 plt_clk_unregister_loop(data
, i
);
348 plt_clk_unregister_parents(data
);
349 plt_clk_free_parent_names_loop(parent_names
, data
->nparents
);
353 static int plt_clk_remove(struct platform_device
*pdev
)
355 struct clk_plt_data
*data
;
357 data
= platform_get_drvdata(pdev
);
359 plt_clk_unregister_loop(data
, PMC_CLK_NUM
);
360 plt_clk_unregister_parents(data
);
364 static struct platform_driver plt_clk_driver
= {
366 .name
= "clk-pmc-atom",
368 .probe
= plt_clk_probe
,
369 .remove
= plt_clk_remove
,
371 builtin_platform_driver(plt_clk_driver
);