diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2012-12-11 12:45:35 -0800 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2012-12-11 12:45:35 -0800 |
commit | bad73c5aa069f1f14cc07ce7bbae8d463635560c (patch) | |
tree | db905bb3400e6fe70be95cd20158bed79b2b2c6c /drivers/cpufreq/spear-cpufreq.c | |
parent | b58ed041a360ed051fab17e4d9b0f451c6fedba7 (diff) | |
parent | f316fc56555a5c3bcf6350f3d5ac26dd2c55f4cb (diff) |
Merge tag 'pm+acpi-for-3.8-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm
Pull ACPI and power management updates from Rafael Wysocki:
- Introduction of device PM QoS flags.
- ACPI device power management update allowing subsystems other than
PCI to use it more easily.
- ACPI device enumeration rework allowing additional kinds of devices
to be enumerated via ACPI. From Mika Westerberg, Adrian Hunter,
Mathias Nyman, Andy Shevchenko, and Rafael J. Wysocki.
- ACPICA update to version 20121018 from Bob Moore and Lv Zheng.
- ACPI memory hotplug update from Wen Congyang and Yasuaki Ishimatsu.
- Introduction of acpi_handle_<level>() messaging macros and ACPI-based
CPU hot-remove support from Toshi Kani.
- ACPI EC updates from Feng Tang.
- cpufreq updates from Viresh Kumar, Fabio Baltieri and others.
- cpuidle changes to quickly notice governor prediction failure from
Youquan Song.
- Support for using multiple cpuidle drivers at the same time and
cpuidle cleanups from Daniel Lezcano.
- devfreq updates from Nishanth Menon and others.
- cpupower update from Thomas Renninger.
- Fixes and small cleanups all over the place.
* tag 'pm+acpi-for-3.8-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (196 commits)
mmc: sdhci-acpi: enable runtime-pm for device HID INT33C6
ACPI: add Haswell LPSS devices to acpi_platform_device_ids list
ACPI: add documentation about ACPI 5 enumeration
pnpacpi: fix incorrect TEST_ALPHA() test
ACPI / PM: Fix header of acpi_dev_pm_detach() in acpi.h
ACPI / video: ignore BIOS initial backlight value for HP Folio 13-2000
ACPI : do not use Lid and Sleep button for S5 wakeup
ACPI / PNP: Do not crash due to stale pointer use during system resume
ACPI / video: Add "Asus UL30VT" to ACPI video detect blacklist
ACPI: do acpisleep dmi check when CONFIG_ACPI_SLEEP is set
spi / ACPI: add ACPI enumeration support
gpio / ACPI: add ACPI support
PM / devfreq: remove compiler error with module governors (2)
cpupower: IvyBridge (0x3a and 0x3e models) support
cpupower: Provide -c param for cpupower monitor to schedule process on all cores
cpupower tools: Fix warning and a bug with the cpu package count
cpupower tools: Fix malloc of cpu_info structure
cpupower tools: Fix issues with sysfs_topology_read_file
cpupower tools: Fix minor warnings
cpupower tools: Update .gitignore for files created in the debug directories
...
Diffstat (limited to 'drivers/cpufreq/spear-cpufreq.c')
-rw-r--r-- | drivers/cpufreq/spear-cpufreq.c | 291 |
1 files changed, 291 insertions, 0 deletions
diff --git a/drivers/cpufreq/spear-cpufreq.c b/drivers/cpufreq/spear-cpufreq.c new file mode 100644 index 00000000000..4575cfe4175 --- /dev/null +++ b/drivers/cpufreq/spear-cpufreq.c @@ -0,0 +1,291 @@ +/* + * drivers/cpufreq/spear-cpufreq.c + * + * CPU Frequency Scaling for SPEAr platform + * + * Copyright (C) 2012 ST Microelectronics + * Deepak Sikri <deepak.sikri@st.com> + * + * This file is licensed under the terms of the GNU General Public + * License version 2. This program is licensed "as is" without any + * warranty of any kind, whether express or implied. + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include <linux/clk.h> +#include <linux/cpufreq.h> +#include <linux/err.h> +#include <linux/init.h> +#include <linux/module.h> +#include <linux/of.h> +#include <linux/slab.h> +#include <linux/types.h> + +/* SPEAr CPUFreq driver data structure */ +static struct { + struct clk *clk; + unsigned int transition_latency; + struct cpufreq_frequency_table *freq_tbl; + u32 cnt; +} spear_cpufreq; + +int spear_cpufreq_verify(struct cpufreq_policy *policy) +{ + return cpufreq_frequency_table_verify(policy, spear_cpufreq.freq_tbl); +} + +static unsigned int spear_cpufreq_get(unsigned int cpu) +{ + return clk_get_rate(spear_cpufreq.clk) / 1000; +} + +static struct clk *spear1340_cpu_get_possible_parent(unsigned long newfreq) +{ + struct clk *sys_pclk; + int pclk; + /* + * In SPEAr1340, cpu clk's parent sys clk can take input from + * following sources + */ + const char *sys_clk_src[] = { + "sys_syn_clk", + "pll1_clk", + "pll2_clk", + "pll3_clk", + }; + + /* + * As sys clk can have multiple source with their own range + * limitation so we choose possible sources accordingly + */ + if (newfreq <= 300000000) + pclk = 0; /* src is sys_syn_clk */ + else if (newfreq > 300000000 && newfreq <= 500000000) + pclk = 3; /* src is pll3_clk */ + else if (newfreq == 600000000) + pclk = 1; /* src is pll1_clk */ + else + return ERR_PTR(-EINVAL); + + /* Get parent to sys clock */ + sys_pclk = clk_get(NULL, sys_clk_src[pclk]); + if (IS_ERR(sys_pclk)) + pr_err("Failed to get %s clock\n", sys_clk_src[pclk]); + + return sys_pclk; +} + +/* + * In SPEAr1340, we cannot use newfreq directly because we need to actually + * access a source clock (clk) which might not be ancestor of cpu at present. + * Hence in SPEAr1340 we would operate on source clock directly before switching + * cpu clock to it. + */ +static int spear1340_set_cpu_rate(struct clk *sys_pclk, unsigned long newfreq) +{ + struct clk *sys_clk; + int ret = 0; + + sys_clk = clk_get_parent(spear_cpufreq.clk); + if (IS_ERR(sys_clk)) { + pr_err("failed to get cpu's parent (sys) clock\n"); + return PTR_ERR(sys_clk); + } + + /* Set the rate of the source clock before changing the parent */ + ret = clk_set_rate(sys_pclk, newfreq); + if (ret) { + pr_err("Failed to set sys clk rate to %lu\n", newfreq); + return ret; + } + + ret = clk_set_parent(sys_clk, sys_pclk); + if (ret) { + pr_err("Failed to set sys clk parent\n"); + return ret; + } + + return 0; +} + +static int spear_cpufreq_target(struct cpufreq_policy *policy, + unsigned int target_freq, unsigned int relation) +{ + struct cpufreq_freqs freqs; + unsigned long newfreq; + struct clk *srcclk; + int index, ret, mult = 1; + + if (cpufreq_frequency_table_target(policy, spear_cpufreq.freq_tbl, + target_freq, relation, &index)) + return -EINVAL; + + freqs.cpu = policy->cpu; + freqs.old = spear_cpufreq_get(0); + + newfreq = spear_cpufreq.freq_tbl[index].frequency * 1000; + if (of_machine_is_compatible("st,spear1340")) { + /* + * SPEAr1340 is special in the sense that due to the possibility + * of multiple clock sources for cpu clk's parent we can have + * different clock source for different frequency of cpu clk. + * Hence we need to choose one from amongst these possible clock + * sources. + */ + srcclk = spear1340_cpu_get_possible_parent(newfreq); + if (IS_ERR(srcclk)) { + pr_err("Failed to get src clk\n"); + return PTR_ERR(srcclk); + } + + /* SPEAr1340: src clk is always 2 * intended cpu clk */ + mult = 2; + } else { + /* + * src clock to be altered is ancestor of cpu clock. Hence we + * can directly work on cpu clk + */ + srcclk = spear_cpufreq.clk; + } + + newfreq = clk_round_rate(srcclk, newfreq * mult); + if (newfreq < 0) { + pr_err("clk_round_rate failed for cpu src clock\n"); + return newfreq; + } + + freqs.new = newfreq / 1000; + freqs.new /= mult; + cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE); + + if (mult == 2) + ret = spear1340_set_cpu_rate(srcclk, newfreq); + else + ret = clk_set_rate(spear_cpufreq.clk, newfreq); + + /* Get current rate after clk_set_rate, in case of failure */ + if (ret) { + pr_err("CPU Freq: cpu clk_set_rate failed: %d\n", ret); + freqs.new = clk_get_rate(spear_cpufreq.clk) / 1000; + } + + cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE); + return ret; +} + +static int spear_cpufreq_init(struct cpufreq_policy *policy) +{ + int ret; + + ret = cpufreq_frequency_table_cpuinfo(policy, spear_cpufreq.freq_tbl); + if (ret) { + pr_err("cpufreq_frequency_table_cpuinfo() failed"); + return ret; + } + + cpufreq_frequency_table_get_attr(spear_cpufreq.freq_tbl, policy->cpu); + policy->cpuinfo.transition_latency = spear_cpufreq.transition_latency; + policy->cur = spear_cpufreq_get(0); + + cpumask_copy(policy->cpus, topology_core_cpumask(policy->cpu)); + cpumask_copy(policy->related_cpus, policy->cpus); + + return 0; +} + +static int spear_cpufreq_exit(struct cpufreq_policy *policy) +{ + cpufreq_frequency_table_put_attr(policy->cpu); + return 0; +} + +static struct freq_attr *spear_cpufreq_attr[] = { + &cpufreq_freq_attr_scaling_available_freqs, + NULL, +}; + +static struct cpufreq_driver spear_cpufreq_driver = { + .name = "cpufreq-spear", + .flags = CPUFREQ_STICKY, + .verify = spear_cpufreq_verify, + .target = spear_cpufreq_target, + .get = spear_cpufreq_get, + .init = spear_cpufreq_init, + .exit = spear_cpufreq_exit, + .attr = spear_cpufreq_attr, +}; + +static int spear_cpufreq_driver_init(void) +{ + struct device_node *np; + const struct property *prop; + struct cpufreq_frequency_table *freq_tbl; + const __be32 *val; + int cnt, i, ret; + + np = of_find_node_by_path("/cpus/cpu@0"); + if (!np) { + pr_err("No cpu node found"); + return -ENODEV; + } + + if (of_property_read_u32(np, "clock-latency", + &spear_cpufreq.transition_latency)) + spear_cpufreq.transition_latency = CPUFREQ_ETERNAL; + + prop = of_find_property(np, "cpufreq_tbl", NULL); + if (!prop || !prop->value) { + pr_err("Invalid cpufreq_tbl"); + ret = -ENODEV; + goto out_put_node; + } + + cnt = prop->length / sizeof(u32); + val = prop->value; + + freq_tbl = kmalloc(sizeof(*freq_tbl) * (cnt + 1), GFP_KERNEL); + if (!freq_tbl) { + ret = -ENOMEM; + goto out_put_node; + } + + for (i = 0; i < cnt; i++) { + freq_tbl[i].index = i; + freq_tbl[i].frequency = be32_to_cpup(val++); + } + + freq_tbl[i].index = i; + freq_tbl[i].frequency = CPUFREQ_TABLE_END; + + spear_cpufreq.freq_tbl = freq_tbl; + + of_node_put(np); + + spear_cpufreq.clk = clk_get(NULL, "cpu_clk"); + if (IS_ERR(spear_cpufreq.clk)) { + pr_err("Unable to get CPU clock\n"); + ret = PTR_ERR(spear_cpufreq.clk); + goto out_put_mem; + } + + ret = cpufreq_register_driver(&spear_cpufreq_driver); + if (!ret) + return 0; + + pr_err("failed register driver: %d\n", ret); + clk_put(spear_cpufreq.clk); + +out_put_mem: + kfree(freq_tbl); + return ret; + +out_put_node: + of_node_put(np); + return ret; +} +late_initcall(spear_cpufreq_driver_init); + +MODULE_AUTHOR("Deepak Sikri <deepak.sikri@st.com>"); +MODULE_DESCRIPTION("SPEAr CPUFreq driver"); +MODULE_LICENSE("GPL"); |