2 * Copyright (C) STMicroelectronics 2009
3 * Copyright (C) ST-Ericsson SA 2010-2012
5 * License Terms: GNU General Public License v2
6 * Author: Sundar Iyer <sundar.iyer@stericsson.com>
7 * Author: Martin Persson <martin.persson@stericsson.com>
8 * Author: Jonas Aaberg <jonas.aberg@stericsson.com>
11 #include <linux/module.h>
12 #include <linux/kernel.h>
13 #include <linux/cpufreq.h>
14 #include <linux/delay.h>
15 #include <linux/slab.h>
16 #include <linux/platform_device.h>
17 #include <linux/clk.h>
19 static struct cpufreq_frequency_table
*freq_table
;
20 static struct clk
*armss_clk
;
22 static int dbx500_cpufreq_target(struct cpufreq_policy
*policy
,
25 /* update armss clk frequency */
26 return clk_set_rate(armss_clk
, freq_table
[index
].frequency
* 1000);
29 static unsigned int dbx500_cpufreq_getspeed(unsigned int cpu
)
32 unsigned long freq
= clk_get_rate(armss_clk
) / 1000;
34 /* The value is rounded to closest frequency in the defined table. */
35 while (freq_table
[i
+ 1].frequency
!= CPUFREQ_TABLE_END
) {
36 if (freq
< freq_table
[i
].frequency
+
37 (freq_table
[i
+ 1].frequency
- freq_table
[i
].frequency
) / 2)
38 return freq_table
[i
].frequency
;
42 return freq_table
[i
].frequency
;
45 static int dbx500_cpufreq_init(struct cpufreq_policy
*policy
)
47 return cpufreq_generic_init(policy
, freq_table
, 20 * 1000);
50 static struct cpufreq_driver dbx500_cpufreq_driver
= {
51 .flags
= CPUFREQ_STICKY
| CPUFREQ_CONST_LOOPS
,
52 .verify
= cpufreq_generic_frequency_table_verify
,
53 .target_index
= dbx500_cpufreq_target
,
54 .get
= dbx500_cpufreq_getspeed
,
55 .init
= dbx500_cpufreq_init
,
57 .attr
= cpufreq_generic_attr
,
60 static int dbx500_cpufreq_probe(struct platform_device
*pdev
)
64 freq_table
= dev_get_platdata(&pdev
->dev
);
66 pr_err("dbx500-cpufreq: Failed to fetch cpufreq table\n");
70 armss_clk
= clk_get(&pdev
->dev
, "armss");
71 if (IS_ERR(armss_clk
)) {
72 pr_err("dbx500-cpufreq: Failed to get armss clk\n");
73 return PTR_ERR(armss_clk
);
76 pr_info("dbx500-cpufreq: Available frequencies:\n");
77 while (freq_table
[i
].frequency
!= CPUFREQ_TABLE_END
) {
78 pr_info(" %d Mhz\n", freq_table
[i
].frequency
/1000);
82 return cpufreq_register_driver(&dbx500_cpufreq_driver
);
85 static struct platform_driver dbx500_cpufreq_plat_driver
= {
87 .name
= "cpufreq-ux500",
90 .probe
= dbx500_cpufreq_probe
,
93 static int __init
dbx500_cpufreq_register(void)
95 return platform_driver_register(&dbx500_cpufreq_plat_driver
);
97 device_initcall(dbx500_cpufreq_register
);
99 MODULE_LICENSE("GPL v2");
100 MODULE_DESCRIPTION("cpufreq driver for DBX500");