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path: root/drivers/cpufreq/tegra186-cpufreq.c
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2022-12-01cpufreq: tegra186: Use flexible array to simplify memory allocationChristophe JAILLET1-7/+4
Use flexible array to simplify memory allocation. It saves some memory, avoids an indirection when reading the 'clusters' array and removes some LoC. Detailed explanation: ==================== Knowing that: - each devm_ allocation over-allocates 40 bytes for internal needs - Some rounding is done by the memory allocator on 8, 16, 32, 64, 96, 128, 192, 256, 512, 1024, 2048, 4096, 8192 boundaries and that: - sizeof(struct tegra186_cpufreq_data) = 24 - sizeof(struct tegra186_cpufreq_cluster) = 16 Memory allocations in tegra186_cpufreq_probe() are: data: (24 + 40) = 64 => 64 bytes data->clusters: (2 * 16 + 40) = 72 => 96 bytes So a total of 160 bytes are allocated. 56 for the real need, 80 for internal uses and 24 are wasted. If 'struct tegra186_cpufreq_data' is reordered so that 'clusters' is a flexible array: - it saves one pointer in the structure - only one allocation is needed So, only 96 bytes are allocated: 16 + 2 * 16 + 40 = 88 => 96 bytes Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2021-10-04cpufreq: tegra186/tegra194: Handle errors in BPMP responseMikko Perttunen1-0/+4
The return value from tegra_bpmp_transfer indicates the success or failure of the IPC transaction with BPMP. If the transaction succeeded, we also need to check the actual command's result code. Add code to do this. While at it, explicitly handle missing CPU clusters, which can occur on floorswept chips. This worked before as well, but possibly only by accident. Signed-off-by: Mikko Perttunen <mperttunen@nvidia.com> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2021-02-04cpufreq: Remove CPUFREQ_STICKY flagViresh Kumar1-1/+1
During cpufreq driver's registration, if the ->init() callback for all the CPUs fail then there is not much point in keeping the driver around as it will only account for more of unnecessary noise, for example cpufreq core will try to suspend/resume the driver which never got registered properly. The removal of such a driver is avoided if the driver carries the CPUFREQ_STICKY flag. This was added way back [1] in 2004 and perhaps no one should ever need it now. A lot of drivers do set this flag, probably because they just copied it from other drivers. This was added earlier for some platforms [2] because their cpufreq drivers were getting registered before the CPUs were registered with subsys framework. And hence they used to fail. The same isn't true anymore though. The current code flow in the kernel is: start_kernel() -> kernel_init() -> kernel_init_freeable() -> do_basic_setup() -> driver_init() -> cpu_dev_init() -> subsys_system_register() //For CPUs -> do_initcalls() -> cpufreq_register_driver() Clearly, the CPUs will always get registered with subsys framework before any cpufreq driver can get probed. Remove the flag and update the relevant drivers. Link: https://git.kernel.org/pub/scm/linux/kernel/git/tglx/history.git/commit/include/linux/cpufreq.h?id=7cc9f0d9a1ab04cedc60d64fd8dcf7df224a3b4d # [1] Link: https://git.kernel.org/pub/scm/linux/kernel/git/tglx/history.git/commit/arch/arm/mach-sa1100/cpu-sa1100.c?id=f59d3bbe35f6268d729f51be82af8325d62f20f5 # [2] Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2020-12-07cpufreq: tegra186: Simplify cluster information lookupJon Hunter1-65/+20
The CPUFREQ driver framework references each individual CPUs when getting and setting the speed. Tegra186 has 3 clusters of A57 CPUs and 1 cluster of Denver CPUs. Hence, the Tegra186 CPUFREQ driver need to know which cluster a given CPU belongs to. The logic in the Tegra186 driver can be greatly simplified by storing the cluster ID associated with each CPU in the tegra186_cpufreq_cpu structure. This allow us to completely remove the Tegra cluster info structure from the driver and simplifiy the code. Signed-off-by: Jon Hunter <jonathanh@nvidia.com> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2020-12-07cpufreq: tegra186: Fix sparse 'incorrect type in assignment' warningJon Hunter1-15/+46
Sparse warns that the incorrect type is being assigned to the CPUFREQ driver_data variable in the Tegra186 CPUFREQ driver. The Tegra186 CPUFREQ driver is assigned a type of 'void __iomem *' to a pointer of type 'void *' ... drivers/cpufreq/tegra186-cpufreq.c:72:37: sparse: sparse: incorrect type in assignment (different address spaces) @@ expected void *driver_data @@ got void [noderef] __iomem * @@ ... drivers/cpufreq/tegra186-cpufreq.c:87:40: sparse: sparse: incorrect type in initializer (different address spaces) @@ expected void [noderef] __iomem *edvd_reg @@ got void *driver_data @@ The Tegra186 CPUFREQ driver is using the policy->driver_data variable to store and iomem pointer to a Tegra186 CPU register that is used to set the clock speed for the CPU. This is not necessary because the register base address is already stored in the driver data and the offset of the register for each CPU is static. Therefore, fix this by adding a new structure with the register offsets for each CPU and store this in the main driver data structure along with the register base address. Please note that a new structure has been added for storing the register offsets rather than a simple array, because this will permit further clean-ups and simplification of the driver. Signed-off-by: Jon Hunter <jonathanh@nvidia.com> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2020-11-17cpufreq: tegra186: Fix get frequency callbackJon Hunter1-12/+21
Commit b89c01c96051 ("cpufreq: tegra186: Fix initial frequency") implemented the CPUFREQ 'get' callback to determine the current operating frequency for each CPU. This implementation used a simple looked up to determine the current operating frequency. The problem with this is that frequency table for different Tegra186 devices may vary and so the default boot frequency for Tegra186 device may or may not be present in the frequency table. If the default boot frequency is not present in the frequency table, this causes the function tegra186_cpufreq_get() to return 0 and in turn causes cpufreq_online() to fail which prevents CPUFREQ from working. Fix this by always calculating the CPU frequency based upon the current 'ndiv' setting for the CPU. Note that the CPU frequency for Tegra186 is calculated by reading the current 'ndiv' setting, multiplying by the CPU reference clock and dividing by a constant divisor. Fixes: b89c01c96051 ("cpufreq: tegra186: Fix initial frequency") Signed-off-by: Jon Hunter <jonathanh@nvidia.com> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2020-09-16cpufreq: tegra186: Fix initial frequencyJon Hunter1-0/+30
Commit 6cc3d0e9a097 ("cpufreq: tegra186: add CPUFREQ_NEED_INITIAL_FREQ_CHECK flag") fixed CPUFREQ support for Tegra186 but as a consequence the following warnings are now seen on boot ... cpufreq: cpufreq_online: CPU0: Running at unlisted freq: 0 KHz cpufreq: cpufreq_online: CPU0: Unlisted initial frequency changed to: 2035200 KHz cpufreq: cpufreq_online: CPU1: Running at unlisted freq: 0 KHz cpufreq: cpufreq_online: CPU1: Unlisted initial frequency changed to: 2035200 KHz cpufreq: cpufreq_online: CPU2: Running at unlisted freq: 0 KHz cpufreq: cpufreq_online: CPU2: Unlisted initial frequency changed to: 2035200 KHz cpufreq: cpufreq_online: CPU3: Running at unlisted freq: 0 KHz cpufreq: cpufreq_online: CPU3: Unlisted initial frequency changed to: 2035200 KHz cpufreq: cpufreq_online: CPU4: Running at unlisted freq: 0 KHz cpufreq: cpufreq_online: CPU4: Unlisted initial frequency changed to: 2035200 KHz cpufreq: cpufreq_online: CPU5: Running at unlisted freq: 0 KHz cpufreq: cpufreq_online: CPU5: Unlisted initial frequency changed to: 2035200 KHz Fix this by adding a 'get' callback for the Tegra186 CPUFREQ driver to retrieve the current operating frequency for a given CPU. The 'get' callback uses the current 'ndiv' value that is programmed to determine that current operating frequency. Signed-off-by: Jon Hunter <jonathanh@nvidia.com> [ Viresh: Return 0 on error ] Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2020-07-30cpufreq: tegra186: Simplify probe return pathJon Hunter1-6/+0
We always put the reference to BPMP device on exit of the Tegra186 CPUFREQ driver and so there is no need to have separate exit paths for success and failure. Therefore, simplify the probe return path in the Tegra186 CPUFREQ driver by combining the success and failure paths. Signed-off-by: Jon Hunter <jonathanh@nvidia.com> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2020-05-18cpufreq: tegra186: add CPUFREQ_NEED_INITIAL_FREQ_CHECK flagMian Yousaf Kaukab1-1/+2
The driver doesn't provide ->get() method to read current frequency and the frequency is set to 0 at initialization which makes the driver fail at initialization time. Set the CPUFREQ_NEED_INITIAL_FREQ_CHECK flag for the driver, so the cpufreq core checks for the unlisted frequency and sets the CPU to a valid frequency from the frequency table. Signed-off-by: Mian Yousaf Kaukab <ykaukab@suse.de> [ Viresh: Massaged change log ] Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2020-01-07cpufreq: tegra186: convert to devm_platform_ioremap_resourceYangtao Li1-3/+1
Use devm_platform_ioremap_resource() to simplify code. Signed-off-by: Yangtao Li <tiny.windzz@gmail.com> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2019-06-05treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 288Thomas Gleixner1-9/+1
Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms and conditions of the gnu general public license version 2 as published by the free software foundation this program is distributed in the hope it will be useful but without any warranty without even the implied warranty of merchantability or fitness for a particular purpose see the gnu general public license for more details extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 263 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Allison Randal <allison@lohutok.net> Reviewed-by: Alexios Zavras <alexios.zavras@intel.com> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190529141901.208660670@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-10-17cpufreq: tegra186: don't pass GFP_DMA32 to dma_alloc_coherent()Christoph Hellwig1-1/+1
The DMA API does its own zone decisions based on the coherent_dma_mask. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2018-03-20cpufreq: tegra186: Don't validate the frequency table twiceViresh Kumar1-1/+1
The cpufreq core is already validating the CPU frequency table after calling the ->init() callback of the cpufreq drivers and the drivers don't need to do the same anymore. Though they need to set the policy->freq_table field directly from the ->init() callback now. Stop validating the frequency table from tegra186 driver. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2018-02-27cpufreq: tegra186: Break after initialization is done for policy->cpuViresh Kumar1-0/+1
There are two clusters (2 + 4 CPUs) on this platform and a separate cpufreq policy is available for each of the CPUs. The loop in tegra186_cpufreq_init() tries to find the structure for the right CPU and finish initialization. But it is missing a `break` statement at the end, which forces it to restart the loop even when the CPU already matched and initialization is done. Fix that by adding the missing `break` statement. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Reviewed-by: Mikko Perttunen <mperttunen@nvidia.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2017-04-19cpufreq: Add Tegra186 cpufreq driverMikko Perttunen1-0/+275
Add a new cpufreq driver for Tegra186 (and likely later). The CPUs are organized into two clusters, Denver and A57, with two and four cores respectively. CPU frequency can be adjusted by writing the desired rate divisor and a voltage hint to a special per-core register. The frequency of each core can be set individually; however, this is just a hint as all CPUs in a cluster will run at the maximum rate of non-idle CPUs in the cluster. Signed-off-by: Mikko Perttunen <mperttunen@nvidia.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>