On 2 March 2013 15:04, Amit Daniel Kachhap <amit.daniel@xxxxxxxxxxx> wrote: > This patch adds dvfs support for exynos5440 SOC. This soc has 4 cores and > they run at same frequency. The nature of exynos5440 clock controller is > different from previous exynos controllers so not using the common exynos > cpufreq framework. The major difference being interrupt notfication for > frequency change. Also, OPP library is used for device tree parsing to get > different parameters like frequency, voltage etc. Since the opp library sorts > the frequency table in ascending order so they are again re-arranged in > descending order. This will have one-to-one mapping with the clock controller > state management logic. > > Signed-off-by: Amit Daniel Kachhap <amit.daniel@xxxxxxxxxxx> > --- > Changes in V2: > * Added OPP library support to parse DT parameters. > * Removed a hack to handle interrupts in bootup. > * Added many review comments from Viresh and Inder. Added? Thanks :) > > All these patches are dependent on Thomas Abraham common clock patches. > http://www.mail-archive.com/linux-samsung-soc@xxxxxxxxxxxxxxx/msg15860.html > > .../bindings/cpufreq/cpufreq-exynos5440.txt | 32 ++ > drivers/cpufreq/Kconfig.arm | 9 + > drivers/cpufreq/Makefile | 1 + > drivers/cpufreq/exynos5440-cpufreq.c | 450 ++++++++++++++++++++ > 4 files changed, 492 insertions(+), 0 deletions(-) > create mode 100644 Documentation/devicetree/bindings/cpufreq/cpufreq-exynos5440.txt > create mode 100644 drivers/cpufreq/exynos5440-cpufreq.c > > diff --git a/Documentation/devicetree/bindings/cpufreq/cpufreq-exynos5440.txt b/Documentation/devicetree/bindings/cpufreq/cpufreq-exynos5440.txt > new file mode 100644 > index 0000000..caa3f8d > --- /dev/null > +++ b/Documentation/devicetree/bindings/cpufreq/cpufreq-exynos5440.txt > @@ -0,0 +1,32 @@ > + > +Exynos5440 cpufreq driver > +------------------- > + > +Exynos5440 SoC cpufreq driver for CPU frequency scaling. > + > +Required properties: > +- interrupts: Interrupt to know the completion of cpu frequency change. > +- operating-points: Table of frequencies and voltage CPU could be transitioned into, > + in the decreasing order. Frequency should be in KHZ units and voltage > + should be in microvolts. > +- clocks: phandle of the clock from common clock binding. More description can > + be found in Documentation/devicetree/bindings/clock/clock-bindings.txt. > + > +Optional properties: > +- clock-latency: Clock transition latency in microsecond. > + > +All the required listed above must be defined under node cpufreq. > + > +Example: > +-------- > + cpufreq@160000 { > + compatible = "samsung,exynos5440-cpufreq"; > + reg = <0x160000 0x1000>; > + interrupts = <0 57 0>; > + operating-points = < > + 1000000 975000 > + 800000 925000>; > + clocks = <&clock 2>; > + clock-latency = <100000>; > + }; > + > diff --git a/drivers/cpufreq/Kconfig.arm b/drivers/cpufreq/Kconfig.arm > index 030ddf6..7ed9c4a 100644 > --- a/drivers/cpufreq/Kconfig.arm > +++ b/drivers/cpufreq/Kconfig.arm > @@ -77,6 +77,15 @@ config ARM_EXYNOS5250_CPUFREQ > This adds the CPUFreq driver for Samsung EXYNOS5250 > SoC. > > +config ARM_EXYNOS5440_CPUFREQ > + def_bool SOC_EXYNOS5440 > + depends on HAVE_CLK && PM_OPP && OF > + help > + This adds the CPUFreq driver for Samsung EXYNOS5440 > + SoC. The nature of exynos5440 clock controller is > + different than previous exynos controllers so not using > + the common exynos framework. > + > config ARM_KIRKWOOD_CPUFREQ > def_bool ARCH_KIRKWOOD && OF > help > diff --git a/drivers/cpufreq/Makefile b/drivers/cpufreq/Makefile > index 863fd18..c841438 100644 > --- a/drivers/cpufreq/Makefile > +++ b/drivers/cpufreq/Makefile > @@ -52,6 +52,7 @@ obj-$(CONFIG_ARM_EXYNOS_CPUFREQ) += exynos-cpufreq.o > obj-$(CONFIG_ARM_EXYNOS4210_CPUFREQ) += exynos4210-cpufreq.o > obj-$(CONFIG_ARM_EXYNOS4X12_CPUFREQ) += exynos4x12-cpufreq.o > obj-$(CONFIG_ARM_EXYNOS5250_CPUFREQ) += exynos5250-cpufreq.o > +obj-$(CONFIG_ARM_EXYNOS5440_CPUFREQ) += exynos5440-cpufreq.o > obj-$(CONFIG_ARM_KIRKWOOD_CPUFREQ) += kirkwood-cpufreq.o > obj-$(CONFIG_ARM_OMAP2PLUS_CPUFREQ) += omap-cpufreq.o > obj-$(CONFIG_ARM_SPEAR_CPUFREQ) += spear-cpufreq.o > diff --git a/drivers/cpufreq/exynos5440-cpufreq.c b/drivers/cpufreq/exynos5440-cpufreq.c > new file mode 100644 > index 0000000..2dc43b1 > --- /dev/null > +++ b/drivers/cpufreq/exynos5440-cpufreq.c > @@ -0,0 +1,450 @@ > +/* > + * Copyright (c) 2013 Samsung Electronics Co., Ltd. > + * http://www.samsung.com > + * > + * Amit Daniel Kachhap <amit.daniel@xxxxxxxxxxx> > + * > + * EXYNOS5440 - CPU frequency scaling support > + * > + * This program is free software; you can redistribute it and/or modify > + * it under the terms of the GNU General Public License version 2 as > + * published by the Free Software Foundation. > +*/ Add following here to get better prints from the driver: #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt > + > +#include <linux/clk.h> > +#include <linux/cpu.h> > +#include <linux/cpufreq.h> > +#include <linux/err.h> > +#include <linux/interrupt.h> > +#include <linux/io.h> > +#include <linux/of_address.h> > +#include <linux/of_irq.h> Probably include of.h instead of above two? > +#include <linux/opp.h> > +#include <linux/slab.h> > + > +struct exynos_dvfs_data { > + void __iomem *base; > + struct resource *mem; > + int irq; > + struct clk *cpu_clk; > + unsigned int cur_frequency; > + unsigned int latency; > + struct cpufreq_frequency_table *freq_table; > + unsigned int freq_count; > + struct device *dev; > + struct work_struct irq_work; > +}; > + > +static struct exynos_dvfs_data *dvfs_info; > +static DEFINE_MUTEX(cpufreq_lock); > +static struct cpufreq_freqs freqs; > + > +static int init_div_table(void) > +{ > + struct cpufreq_frequency_table *freq_tbl = dvfs_info->freq_table; > + unsigned int tmp, clk_div, ema_div, freq, volt_id; > + int i = 0; > + struct opp *opp; > + > + for (i = 0; freq_tbl[i].frequency != CPUFREQ_TABLE_END; i++) { > + > + opp = opp_find_freq_exact(dvfs_info->dev, > + freq_tbl[i].frequency * 1000, true); > + if (IS_ERR(opp)) { > + pr_err("failed to find valid OPP for %u KHZ\n", > + freq_tbl[i].frequency); > + return PTR_ERR(opp); > + } > + > + freq = freq_tbl[i].frequency / 1000; /*In MHZ*/ > + clk_div = ((freq / CPU_DIV_FREQ_MAX) & P0_7_CPUCLKDEV_MASK) > + << P0_7_CPUCLKDEV_SHIFT; > + clk_div |= ((freq / CPU_ATB_FREQ_MAX) & P0_7_ATBCLKDEV_MASK) > + << P0_7_ATBCLKDEV_SHIFT; > + clk_div |= ((freq / CPU_DBG_FREQ_MAX) & P0_7_CSCLKDEV_MASK) > + << P0_7_CSCLKDEV_SHIFT; > + > + /*Calculate EMA*/ > + volt_id = opp_get_voltage(opp); > + volt_id = (MAX_VOLTAGE - volt_id) / VOLTAGE_STEP; > + if (volt_id < PMIC_HIGH_VOLT) { > + ema_div = (CPUEMA_HIGH << P0_7_CPUEMA_SHIFT) | > + (L2EMA_HIGH << P0_7_L2EMA_SHIFT); > + } else if (volt_id > PMIC_LOW_VOLT) { > + ema_div = (CPUEMA_LOW << P0_7_CPUEMA_SHIFT) | > + (L2EMA_LOW << P0_7_L2EMA_SHIFT); > + } else { > + ema_div = (CPUEMA_MID << P0_7_CPUEMA_SHIFT) | > + (L2EMA_MID << P0_7_L2EMA_SHIFT); > + } > + > + tmp = (clk_div | ema_div | (volt_id << P0_7_VDD_SHIFT) > + | ((freq / FREQ_UNIT) << P0_7_FREQ_SHIFT)); > + > + __raw_writel(tmp, dvfs_info->base + XMU_PMU_P0_7 + 4 * i); > + } > + > + return 0; > +} > + > +void exynos_enable_dvfs(void) > +{ > + unsigned int tmp, i, cpu; > + struct cpufreq_frequency_table *freq_table = dvfs_info->freq_table; > + /*Disable DVFS*/ Please give space after /* and before */ all over your driver. > + __raw_writel(0, dvfs_info->base + XMU_DVFS_CTRL); > + > + /*Enable PSTATE Change Event*/ > + tmp = __raw_readl(dvfs_info->base + XMU_PMUEVTEN); > + tmp |= (1 << PSTATE_CHANGED_EVTEN_SHIFT); > + __raw_writel(tmp, dvfs_info->base + XMU_PMUEVTEN); > + > + /Enable* PSTATE Change IRQ*/ > + tmp = __raw_readl(dvfs_info->base + XMU_PMUIRQEN); > + tmp |= (1 << PSTATE_CHANGED_IRQEN_SHIFT); > + __raw_writel(tmp, dvfs_info->base + XMU_PMUIRQEN); > + > + /*Set initial performance index*/ > + for (i = 0; freq_table[i].frequency != CPUFREQ_TABLE_END; i++) > + if (freq_table[i].frequency == dvfs_info->cur_frequency) > + break; > + > + if (freq_table[i].frequency == CPUFREQ_TABLE_END) { > + pr_crit("Boot up frequency not supported\n"); > + /*Assign the highest frequency*/ > + i = 0; > + dvfs_info->cur_frequency = freq_table[i].frequency; > + } > + > + pr_info("Setting dvfs initial frequency = %u", > + dvfs_info->cur_frequency); > + > + for (cpu = 0; cpu < CONFIG_NR_CPUS; cpu++) { > + tmp = __raw_readl(dvfs_info->base + XMU_C0_3_PSTATE + cpu * 4); > + tmp &= ~(P_VALUE_MASK << C0_3_PSTATE_NEW_SHIFT); > + tmp |= (i << C0_3_PSTATE_NEW_SHIFT); > + __raw_writel(tmp, dvfs_info->base + XMU_C0_3_PSTATE + cpu * 4); > + } > + > + /*Enable DVFS*/ > + __raw_writel(1 << XMU_DVFS_CTRL_EN_SHIFT, > + dvfs_info->base + XMU_DVFS_CTRL); > +} > + > +static int exynos_verify_speed(struct cpufreq_policy *policy) > +{ > + return cpufreq_frequency_table_verify(policy, > + dvfs_info->freq_table); > +} > + > +static unsigned int exynos_getspeed(unsigned int cpu) > +{ > + return dvfs_info->cur_frequency; > +} > + > +static int exynos_target(struct cpufreq_policy *policy, > + unsigned int target_freq, > + unsigned int relation) > +{ > + unsigned int index, tmp; > + int ret = 0, i; > + struct cpufreq_frequency_table *freq_table = dvfs_info->freq_table; > + > + mutex_lock(&cpufreq_lock); > + freqs.old = dvfs_info->cur_frequency; > + > + if (cpufreq_frequency_table_target(policy, freq_table, > + target_freq, relation, &index)) { > + ret = -EINVAL; > + goto out; > + } > + > + freqs.new = freq_table[index].frequency; > + freqs.cpu = policy->cpu; > + > + for_each_cpu(freqs.cpu, policy->cpus) > + cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE); > + > + /*Set the target frequency in all C0_3_PSTATE register*/ > + for_each_cpu(i, policy->cpus) { > + tmp = __raw_readl(dvfs_info->base + XMU_C0_3_PSTATE + i * 4); > + tmp &= ~(P_VALUE_MASK << C0_3_PSTATE_NEW_SHIFT); > + tmp |= (index << C0_3_PSTATE_NEW_SHIFT); > + > + __raw_writel(tmp, dvfs_info->base + XMU_C0_3_PSTATE + i * 4); > + } > +out: > + mutex_unlock(&cpufreq_lock); > + return ret; > +} > + > +static void exynos_cpufreq_work(struct work_struct *work) > +{ > + unsigned int cur_pstate, index; > + struct cpufreq_policy *policy = cpufreq_cpu_get(0); /* boot CPU */ > + struct cpufreq_frequency_table *freq_table = dvfs_info->freq_table; > + > + if (policy == NULL) > + goto skip_work; How can that be true? And if it can be, you will miss POSTCHANGE notifications too. > + mutex_lock(&cpufreq_lock); > + freqs.old = dvfs_info->cur_frequency; > + > + cur_pstate = __raw_readl(dvfs_info->base + XMU_P_STATUS); > + if (cur_pstate >> C0_3_PSTATE_VALID_SHIFT & 0x1) > + index = (cur_pstate >> C0_3_PSTATE_CURR_SHIFT) & P_VALUE_MASK; > + else > + index = (cur_pstate >> C0_3_PSTATE_NEW_SHIFT) & P_VALUE_MASK; > + > + if (index < dvfs_info->freq_count) { What if index is greater than count? That's a problem, isn't it? > + freqs.new = freq_table[index].frequency; > + for_each_cpu(freqs.cpu, policy->cpus) > + cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE); > + dvfs_info->cur_frequency = freqs.new; > + } > + > + cpufreq_cpu_put(policy); > + mutex_unlock(&cpufreq_lock); > +skip_work: > + enable_irq(dvfs_info->irq); > +} > + > +static irqreturn_t exynos_cpufreq_irq(int irq, void *id) > +{ > + unsigned int tmp; > + > + tmp = __raw_readl(dvfs_info->base + XMU_PMUIRQ); > + if (tmp >> PSTATE_CHANGED_SHIFT & 0x1) { > + __raw_writel(tmp, dvfs_info->base + XMU_PMUIRQ); > + disable_irq_nosync(irq); > + schedule_work(&dvfs_info->irq_work); > + } > + return IRQ_HANDLED; > +} > + > +static void exynos_sort_descend_freq_table(void) > +{ > + struct cpufreq_frequency_table *freq_tbl = dvfs_info->freq_table; > + int i = 0, index; > + unsigned int tmp_freq; > + > + /* > + *Freq table is already in ascending order as it is created from You need space after * here too :) > + *OPP library, so just swap the elements to make it descending. > + */ > + for (i = 0; i < dvfs_info->freq_count / 2; i++) { > + index = dvfs_info->freq_count - i - 1; > + tmp_freq = freq_tbl[i].frequency; > + freq_tbl[i].frequency = freq_tbl[index].frequency; > + freq_tbl[index].frequency = tmp_freq; > + } > +} > + > +static int exynos_cpufreq_cpu_init(struct cpufreq_policy *policy) > +{ > + > + policy->cur = dvfs_info->cur_frequency; > + cpufreq_frequency_table_get_attr(dvfs_info->freq_table, policy->cpu); > + > + /* set the transition latency value */ > + policy->cpuinfo.transition_latency = dvfs_info->latency; > + > + cpumask_setall(policy->cpus); > + > + return cpufreq_frequency_table_cpuinfo(policy, dvfs_info->freq_table); > +} > + > +static struct cpufreq_driver exynos_driver = { > + .flags = CPUFREQ_STICKY, > + .verify = exynos_verify_speed, > + .target = exynos_target, > + .get = exynos_getspeed, > + .init = exynos_cpufreq_cpu_init, > + .name = DRIVER_NAME, > +}; > + > +static int __init exynos_cpufreq_init(void) probably calling it probe might make more sense? > +{ > + int ret = -EINVAL; > + struct device_node *np; > + > + np = of_find_compatible_node(NULL, NULL, "samsung,exynos5440-cpufreq"); > + if (IS_ERR(np)) !np ?? > + return -ENODEV; > + > + dvfs_info = kzalloc(sizeof(struct exynos_dvfs_data), GFP_KERNEL); sizeof(*dvfs_info) ?? > + if (IS_ERR(dvfs_info)) { IS_ERR_OR_NULL? But i believe kzalloc only returns NULL to show error, so you may end up using if(!dvfs_info) > + ret = -ENOMEM; > + goto err_mem_data; > + } > + > + dvfs_info->base = of_iomap(np, 0); > + if (IS_ERR(dvfs_info->base)) { same here too.. > + pr_err("No cpufreq memory map found\n"); > + ret = -ENODEV; > + goto err_map; > + } > + > + dvfs_info->irq = irq_of_parse_and_map(np, 0); > + can remove blank line. > + if (dvfs_info->irq == 0) { > + pr_err("No cpufreq irq found\n"); > + ret = -ENODEV; > + goto err_irq_parse; > + } > + > + dvfs_info->dev = get_cpu_device(0); What about using this dev instance to call devm_*** routines everywhere in init. > + if (IS_ERR(dvfs_info->dev)) { > + pr_err("failed to get cpu0 device\n"); > + ret = -ENODEV; > + goto err_irq_parse; > + } > + > + dvfs_info->dev->of_node = np; So you are setting cpufreq node as node of cpu, I don't know if this is a good idea. In that case it would be better to create the cpu node instead and put the table into it. > + ret = of_init_opp_table(dvfs_info->dev); > + if (ret) { > + pr_err("failed to init OPP table: %d\n", ret); > + goto err_irq_parse; > + } > + > + ret = opp_init_cpufreq_table(dvfs_info->dev, &dvfs_info->freq_table); > + if (ret) { > + pr_err("failed to init cpufreq table: %d\n", ret); > + goto err_irq_parse; > + } > + dvfs_info->freq_count = opp_get_opp_count(dvfs_info->dev); > + exynos_sort_descend_freq_table(); > + > + if (of_property_read_u32(np, "clock-latency", &dvfs_info->latency)) > + dvfs_info->latency = DEF_TRANS_LATENCY; > + > + dvfs_info->cpu_clk = of_clk_get(np, 0); > + if (IS_ERR(dvfs_info->cpu_clk)) { > + pr_err("Failed to get cpu clock\n"); > + ret = PTR_ERR(dvfs_info->cpu_clk); > + goto err_clk_get; > + } > + > + dvfs_info->cur_frequency = clk_get_rate(dvfs_info->cpu_clk); > + if (!dvfs_info->cur_frequency) { > + pr_err("Failed to get clock rate\n"); > + ret = -EINVAL; > + goto err_clk_get_rate; > + } > + dvfs_info->cur_frequency /= 1000; > + > + INIT_WORK(&dvfs_info->irq_work, exynos_cpufreq_work); > + if (request_irq(dvfs_info->irq, exynos_cpufreq_irq, > + IRQF_TRIGGER_NONE, DRIVER_NAME, dvfs_info)) { > + pr_err("Failed to register IRQ\n"); > + ret = -ENODEV; > + goto err_clk_get_rate; > + } > + > + ret = init_div_table(); > + if (ret) { > + pr_err("Failed to initialise div table\n"); s/initialise/initialize > + goto err_div_table; > + } > + > + exynos_enable_dvfs(); > + ret = cpufreq_register_driver(&exynos_driver); > + if (ret) { > + pr_err("%s: failed to register cpufreq driver\n", __func__); > + goto err_div_table; > + } > + > + of_node_put(np); > + > + pr_info("exynos5440 DVFS initialised.\n"); > + > + return 0; > + > +err_div_table: > + free_irq(dvfs_info->irq, dvfs_info); > +err_clk_get_rate: > + clk_put(dvfs_info->cpu_clk); > +err_clk_get: > + opp_free_cpufreq_table(dvfs_info->dev, &dvfs_info->freq_table); > +err_irq_parse: > + iounmap(dvfs_info->base); > +err_map: > + kfree(dvfs_info); > +err_mem_data: > + of_node_put(np); > + pr_err("%s: failed initialization\n", __func__); > + return ret; > +} > +late_initcall(exynos_cpufreq_init); > -- > 1.7.1 > -- To unsubscribe from this list: send the line "unsubscribe linux-samsung-soc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
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