| Author | Tokens | Token Proportion | Commits | Commit Proportion |
|---|---|---|---|---|
| Lukasz Luba | 5882 | 97.81% | 6 | 27.27% |
| Krzysztof Kozlowski | 57 | 0.95% | 6 | 27.27% |
| Miaoqian Lin | 43 | 0.71% | 1 | 4.55% |
| Yangtao Li | 11 | 0.18% | 2 | 9.09% |
| Chanwoo Choi | 9 | 0.15% | 2 | 9.09% |
| Christophe Jaillet | 7 | 0.12% | 1 | 4.55% |
| Uwe Kleine-König | 2 | 0.03% | 1 | 4.55% |
| Bernard Zhao | 1 | 0.02% | 1 | 4.55% |
| Colin Ian King | 1 | 0.02% | 1 | 4.55% |
| Rob Herring | 1 | 0.02% | 1 | 4.55% |
| Total | 6014 | 22 |
// SPDX-License-Identifier: GPL-2.0 /* * Copyright (c) 2019 Samsung Electronics Co., Ltd. * Author: Lukasz Luba <l.luba@partner.samsung.com> */ #include <linux/clk.h> #include <linux/devfreq.h> #include <linux/devfreq-event.h> #include <linux/device.h> #include <linux/interrupt.h> #include <linux/io.h> #include <linux/mfd/syscon.h> #include <linux/module.h> #include <linux/moduleparam.h> #include <linux/of.h> #include <linux/pm_opp.h> #include <linux/platform_device.h> #include <linux/regmap.h> #include <linux/regulator/consumer.h> #include <linux/slab.h> #include "../jedec_ddr.h" #include "../of_memory.h" static int irqmode; module_param(irqmode, int, 0644); MODULE_PARM_DESC(irqmode, "Enable IRQ mode (0=off [default], 1=on)"); #define EXYNOS5_DREXI_TIMINGAREF (0x0030) #define EXYNOS5_DREXI_TIMINGROW0 (0x0034) #define EXYNOS5_DREXI_TIMINGDATA0 (0x0038) #define EXYNOS5_DREXI_TIMINGPOWER0 (0x003C) #define EXYNOS5_DREXI_TIMINGROW1 (0x00E4) #define EXYNOS5_DREXI_TIMINGDATA1 (0x00E8) #define EXYNOS5_DREXI_TIMINGPOWER1 (0x00EC) #define CDREX_PAUSE (0x2091c) #define CDREX_LPDDR3PHY_CON3 (0x20a20) #define CDREX_LPDDR3PHY_CLKM_SRC (0x20700) #define EXYNOS5_TIMING_SET_SWI BIT(28) #define USE_MX_MSPLL_TIMINGS (1) #define USE_BPLL_TIMINGS (0) #define EXYNOS5_AREF_NORMAL (0x2e) #define DREX_PPCCLKCON (0x0130) #define DREX_PEREV2CONFIG (0x013c) #define DREX_PMNC_PPC (0xE000) #define DREX_CNTENS_PPC (0xE010) #define DREX_CNTENC_PPC (0xE020) #define DREX_INTENS_PPC (0xE030) #define DREX_INTENC_PPC (0xE040) #define DREX_FLAG_PPC (0xE050) #define DREX_PMCNT2_PPC (0xE130) /* * A value for register DREX_PMNC_PPC which should be written to reset * the cycle counter CCNT (a reference wall clock). It sets zero to the * CCNT counter. */ #define CC_RESET BIT(2) /* * A value for register DREX_PMNC_PPC which does the reset of all performance * counters to zero. */ #define PPC_COUNTER_RESET BIT(1) /* * Enables all configured counters (including cycle counter). The value should * be written to the register DREX_PMNC_PPC. */ #define PPC_ENABLE BIT(0) /* A value for register DREX_PPCCLKCON which enables performance events clock. * Must be written before first access to the performance counters register * set, otherwise it could crash. */ #define PEREV_CLK_EN BIT(0) /* * Values which are used to enable counters, interrupts or configure flags of * the performance counters. They configure counter 2 and cycle counter. */ #define PERF_CNT2 BIT(2) #define PERF_CCNT BIT(31) /* * Performance event types which are used for setting the preferred event * to track in the counters. * There is a set of different types, the values are from range 0 to 0x6f. * These settings should be written to the configuration register which manages * the type of the event (register DREX_PEREV2CONFIG). */ #define READ_TRANSFER_CH0 (0x6d) #define READ_TRANSFER_CH1 (0x6f) #define PERF_COUNTER_START_VALUE 0xff000000 #define PERF_EVENT_UP_DOWN_THRESHOLD 900000000ULL /** * struct dmc_opp_table - Operating level desciption * @freq_hz: target frequency in Hz * @volt_uv: target voltage in uV * * Covers frequency and voltage settings of the DMC operating mode. */ struct dmc_opp_table { u32 freq_hz; u32 volt_uv; }; /** * struct exynos5_dmc - main structure describing DMC device * @dev: DMC device * @df: devfreq device structure returned by devfreq framework * @gov_data: configuration of devfreq governor * @base_drexi0: DREX0 registers mapping * @base_drexi1: DREX1 registers mapping * @clk_regmap: regmap for clock controller registers * @lock: protects curr_rate and frequency/voltage setting section * @curr_rate: current frequency * @curr_volt: current voltage * @opp: OPP table * @opp_count: number of 'opp' elements * @timings_arr_size: number of 'timings' elements * @timing_row: values for timing row register, for each OPP * @timing_data: values for timing data register, for each OPP * @timing_power: balues for timing power register, for each OPP * @timings: DDR memory timings, from device tree * @min_tck: DDR memory minimum timing values, from device tree * @bypass_timing_row: value for timing row register for bypass timings * @bypass_timing_data: value for timing data register for bypass timings * @bypass_timing_power: value for timing power register for bypass * timings * @vdd_mif: Memory interface regulator * @fout_spll: clock: SPLL * @fout_bpll: clock: BPLL * @mout_spll: clock: mux SPLL * @mout_bpll: clock: mux BPLL * @mout_mclk_cdrex: clock: mux mclk_cdrex * @mout_mx_mspll_ccore: clock: mux mx_mspll_ccore * @counter: devfreq events * @num_counters: number of 'counter' elements * @last_overflow_ts: time (in ns) of last overflow of each DREX * @load: utilization in percents * @total: total time between devfreq events * @in_irq_mode: whether running in interrupt mode (true) * or polling (false) * * The main structure for the Dynamic Memory Controller which covers clocks, * memory regions, HW information, parameters and current operating mode. */ struct exynos5_dmc { struct device *dev; struct devfreq *df; struct devfreq_simple_ondemand_data gov_data; void __iomem *base_drexi0; void __iomem *base_drexi1; struct regmap *clk_regmap; /* Protects curr_rate and frequency/voltage setting section */ struct mutex lock; unsigned long curr_rate; unsigned long curr_volt; struct dmc_opp_table *opp; int opp_count; u32 timings_arr_size; u32 *timing_row; u32 *timing_data; u32 *timing_power; const struct lpddr3_timings *timings; const struct lpddr3_min_tck *min_tck; u32 bypass_timing_row; u32 bypass_timing_data; u32 bypass_timing_power; struct regulator *vdd_mif; struct clk *fout_spll; struct clk *fout_bpll; struct clk *mout_spll; struct clk *mout_bpll; struct clk *mout_mclk_cdrex; struct clk *mout_mx_mspll_ccore; struct devfreq_event_dev **counter; int num_counters; u64 last_overflow_ts[2]; unsigned long load; unsigned long total; bool in_irq_mode; }; #define TIMING_FIELD(t_name, t_bit_beg, t_bit_end) \ { .name = t_name, .bit_beg = t_bit_beg, .bit_end = t_bit_end } #define TIMING_VAL2REG(timing, t_val) \ ({ \ u32 __val; \ __val = (t_val) << (timing)->bit_beg; \ __val; \ }) struct timing_reg { char *name; int bit_beg; int bit_end; unsigned int val; }; static const struct timing_reg timing_row_reg_fields[] = { TIMING_FIELD("tRFC", 24, 31), TIMING_FIELD("tRRD", 20, 23), TIMING_FIELD("tRP", 16, 19), TIMING_FIELD("tRCD", 12, 15), TIMING_FIELD("tRC", 6, 11), TIMING_FIELD("tRAS", 0, 5), }; static const struct timing_reg timing_data_reg_fields[] = { TIMING_FIELD("tWTR", 28, 31), TIMING_FIELD("tWR", 24, 27), TIMING_FIELD("tRTP", 20, 23), TIMING_FIELD("tW2W-C2C", 14, 14), TIMING_FIELD("tR2R-C2C", 12, 12), TIMING_FIELD("WL", 8, 11), TIMING_FIELD("tDQSCK", 4, 7), TIMING_FIELD("RL", 0, 3), }; static const struct timing_reg timing_power_reg_fields[] = { TIMING_FIELD("tFAW", 26, 31), TIMING_FIELD("tXSR", 16, 25), TIMING_FIELD("tXP", 8, 15), TIMING_FIELD("tCKE", 4, 7), TIMING_FIELD("tMRD", 0, 3), }; #define TIMING_COUNT (ARRAY_SIZE(timing_row_reg_fields) + \ ARRAY_SIZE(timing_data_reg_fields) + \ ARRAY_SIZE(timing_power_reg_fields)) static int exynos5_counters_set_event(struct exynos5_dmc *dmc) { int i, ret; for (i = 0; i < dmc->num_counters; i++) { if (!dmc->counter[i]) continue; ret = devfreq_event_set_event(dmc->counter[i]); if (ret < 0) return ret; } return 0; } static int exynos5_counters_enable_edev(struct exynos5_dmc *dmc) { int i, ret; for (i = 0; i < dmc->num_counters; i++) { if (!dmc->counter[i]) continue; ret = devfreq_event_enable_edev(dmc->counter[i]); if (ret < 0) return ret; } return 0; } static int exynos5_counters_disable_edev(struct exynos5_dmc *dmc) { int i, ret; for (i = 0; i < dmc->num_counters; i++) { if (!dmc->counter[i]) continue; ret = devfreq_event_disable_edev(dmc->counter[i]); if (ret < 0) return ret; } return 0; } /** * find_target_freq_idx() - Finds requested frequency in local DMC configuration * @dmc: device for which the information is checked * @target_rate: requested frequency in KHz * * Seeks in the local DMC driver structure for the requested frequency value * and returns index or error value. */ static int find_target_freq_idx(struct exynos5_dmc *dmc, unsigned long target_rate) { int i; for (i = dmc->opp_count - 1; i >= 0; i--) if (dmc->opp[i].freq_hz <= target_rate) return i; return -EINVAL; } /** * exynos5_switch_timing_regs() - Changes bank register set for DRAM timings * @dmc: device for which the new settings is going to be applied * @set: boolean variable passing set value * * Changes the register set, which holds timing parameters. * There is two register sets: 0 and 1. The register set 0 * is used in normal operation when the clock is provided from main PLL. * The bank register set 1 is used when the main PLL frequency is going to be * changed and the clock is taken from alternative, stable source. * This function switches between these banks according to the * currently used clock source. */ static int exynos5_switch_timing_regs(struct exynos5_dmc *dmc, bool set) { unsigned int reg; int ret; ret = regmap_read(dmc->clk_regmap, CDREX_LPDDR3PHY_CON3, ®); if (ret) return ret; if (set) reg |= EXYNOS5_TIMING_SET_SWI; else reg &= ~EXYNOS5_TIMING_SET_SWI; regmap_write(dmc->clk_regmap, CDREX_LPDDR3PHY_CON3, reg); return 0; } /** * exynos5_init_freq_table() - Initialized PM OPP framework * @dmc: DMC device for which the frequencies are used for OPP init * @profile: devfreq device's profile * * Populate the devfreq device's OPP table based on current frequency, voltage. */ static int exynos5_init_freq_table(struct exynos5_dmc *dmc, struct devfreq_dev_profile *profile) { int i, ret; int idx; unsigned long freq; ret = devm_pm_opp_of_add_table(dmc->dev); if (ret < 0) { dev_err(dmc->dev, "Failed to get OPP table\n"); return ret; } dmc->opp_count = dev_pm_opp_get_opp_count(dmc->dev); dmc->opp = devm_kmalloc_array(dmc->dev, dmc->opp_count, sizeof(struct dmc_opp_table), GFP_KERNEL); if (!dmc->opp) return -ENOMEM; idx = dmc->opp_count - 1; for (i = 0, freq = ULONG_MAX; i < dmc->opp_count; i++, freq--) { struct dev_pm_opp *opp; opp = dev_pm_opp_find_freq_floor(dmc->dev, &freq); if (IS_ERR(opp)) return PTR_ERR(opp); dmc->opp[idx - i].freq_hz = freq; dmc->opp[idx - i].volt_uv = dev_pm_opp_get_voltage(opp); dev_pm_opp_put(opp); } return 0; } /** * exynos5_set_bypass_dram_timings() - Low-level changes of the DRAM timings * @dmc: device for which the new settings is going to be applied * * Low-level function for changing timings for DRAM memory clocking from * 'bypass' clock source (fixed frequency @400MHz). * It uses timing bank registers set 1. */ static void exynos5_set_bypass_dram_timings(struct exynos5_dmc *dmc) { writel(EXYNOS5_AREF_NORMAL, dmc->base_drexi0 + EXYNOS5_DREXI_TIMINGAREF); writel(dmc->bypass_timing_row, dmc->base_drexi0 + EXYNOS5_DREXI_TIMINGROW1); writel(dmc->bypass_timing_row, dmc->base_drexi1 + EXYNOS5_DREXI_TIMINGROW1); writel(dmc->bypass_timing_data, dmc->base_drexi0 + EXYNOS5_DREXI_TIMINGDATA1); writel(dmc->bypass_timing_data, dmc->base_drexi1 + EXYNOS5_DREXI_TIMINGDATA1); writel(dmc->bypass_timing_power, dmc->base_drexi0 + EXYNOS5_DREXI_TIMINGPOWER1); writel(dmc->bypass_timing_power, dmc->base_drexi1 + EXYNOS5_DREXI_TIMINGPOWER1); } /** * exynos5_dram_change_timings() - Low-level changes of the DRAM final timings * @dmc: device for which the new settings is going to be applied * @target_rate: target frequency of the DMC * * Low-level function for changing timings for DRAM memory operating from main * clock source (BPLL), which can have different frequencies. Thus, each * frequency must have corresponding timings register values in order to keep * the needed delays. * It uses timing bank registers set 0. */ static int exynos5_dram_change_timings(struct exynos5_dmc *dmc, unsigned long target_rate) { int idx; for (idx = dmc->opp_count - 1; idx >= 0; idx--) if (dmc->opp[idx].freq_hz <= target_rate) break; if (idx < 0) return -EINVAL; writel(EXYNOS5_AREF_NORMAL, dmc->base_drexi0 + EXYNOS5_DREXI_TIMINGAREF); writel(dmc->timing_row[idx], dmc->base_drexi0 + EXYNOS5_DREXI_TIMINGROW0); writel(dmc->timing_row[idx], dmc->base_drexi1 + EXYNOS5_DREXI_TIMINGROW0); writel(dmc->timing_data[idx], dmc->base_drexi0 + EXYNOS5_DREXI_TIMINGDATA0); writel(dmc->timing_data[idx], dmc->base_drexi1 + EXYNOS5_DREXI_TIMINGDATA0); writel(dmc->timing_power[idx], dmc->base_drexi0 + EXYNOS5_DREXI_TIMINGPOWER0); writel(dmc->timing_power[idx], dmc->base_drexi1 + EXYNOS5_DREXI_TIMINGPOWER0); return 0; } /** * exynos5_dmc_align_target_voltage() - Sets the final voltage for the DMC * @dmc: device for which it is going to be set * @target_volt: new voltage which is chosen to be final * * Function tries to align voltage to the safe level for 'normal' mode. * It checks the need of higher voltage and changes the value. The target * voltage might be lower that currently set and still the system will be * stable. */ static int exynos5_dmc_align_target_voltage(struct exynos5_dmc *dmc, unsigned long target_volt) { int ret = 0; if (dmc->curr_volt <= target_volt) return 0; ret = regulator_set_voltage(dmc->vdd_mif, target_volt, target_volt); if (!ret) dmc->curr_volt = target_volt; return ret; } /** * exynos5_dmc_align_bypass_voltage() - Sets the voltage for the DMC * @dmc: device for which it is going to be set * @target_volt: new voltage which is chosen to be final * * Function tries to align voltage to the safe level for the 'bypass' mode. * It checks the need of higher voltage and changes the value. * The target voltage must not be less than currently needed, because * for current frequency the device might become unstable. */ static int exynos5_dmc_align_bypass_voltage(struct exynos5_dmc *dmc, unsigned long target_volt) { int ret = 0; if (dmc->curr_volt >= target_volt) return 0; ret = regulator_set_voltage(dmc->vdd_mif, target_volt, target_volt); if (!ret) dmc->curr_volt = target_volt; return ret; } /** * exynos5_dmc_align_bypass_dram_timings() - Chooses and sets DRAM timings * @dmc: device for which it is going to be set * @target_rate: new frequency which is chosen to be final * * Function changes the DRAM timings for the temporary 'bypass' mode. */ static int exynos5_dmc_align_bypass_dram_timings(struct exynos5_dmc *dmc, unsigned long target_rate) { int idx = find_target_freq_idx(dmc, target_rate); if (idx < 0) return -EINVAL; exynos5_set_bypass_dram_timings(dmc); return 0; } /** * exynos5_dmc_switch_to_bypass_configuration() - Switching to temporary clock * @dmc: DMC device for which the switching is going to happen * @target_rate: new frequency which is going to be set as a final * @target_volt: new voltage which is going to be set as a final * * Function configures DMC and clocks for operating in temporary 'bypass' mode. * This mode is used only temporary but if required, changes voltage and timings * for DRAM chips. It switches the main clock to stable clock source for the * period of the main PLL reconfiguration. */ static int exynos5_dmc_switch_to_bypass_configuration(struct exynos5_dmc *dmc, unsigned long target_rate, unsigned long target_volt) { int ret; /* * Having higher voltage for a particular frequency does not harm * the chip. Use it for the temporary frequency change when one * voltage manipulation might be avoided. */ ret = exynos5_dmc_align_bypass_voltage(dmc, target_volt); if (ret) return ret; /* * Longer delays for DRAM does not cause crash, the opposite does. */ ret = exynos5_dmc_align_bypass_dram_timings(dmc, target_rate); if (ret) return ret; /* * Delays are long enough, so use them for the new coming clock. */ ret = exynos5_switch_timing_regs(dmc, USE_MX_MSPLL_TIMINGS); return ret; } /** * exynos5_dmc_change_freq_and_volt() - Changes voltage and frequency of the DMC * using safe procedure * @dmc: device for which the frequency is going to be changed * @target_rate: requested new frequency * @target_volt: requested voltage which corresponds to the new frequency * * The DMC frequency change procedure requires a few steps. * The main requirement is to change the clock source in the clk mux * for the time of main clock PLL locking. The assumption is that the * alternative clock source set as parent is stable. * The second parent's clock frequency is fixed to 400MHz, it is named 'bypass' * clock. This requires alignment in DRAM timing parameters for the new * T-period. There is two bank sets for keeping DRAM * timings: set 0 and set 1. The set 0 is used when main clock source is * chosen. The 2nd set of regs is used for 'bypass' clock. Switching between * the two bank sets is part of the process. * The voltage must also be aligned to the minimum required level. There is * this intermediate step with switching to 'bypass' parent clock source. * if the old voltage is lower, it requires an increase of the voltage level. * The complexity of the voltage manipulation is hidden in low level function. * In this function there is last alignment of the voltage level at the end. */ static int exynos5_dmc_change_freq_and_volt(struct exynos5_dmc *dmc, unsigned long target_rate, unsigned long target_volt) { int ret; ret = exynos5_dmc_switch_to_bypass_configuration(dmc, target_rate, target_volt); if (ret) return ret; /* * Voltage is set at least to a level needed for this frequency, * so switching clock source is safe now. */ clk_prepare_enable(dmc->fout_spll); clk_prepare_enable(dmc->mout_spll); clk_prepare_enable(dmc->mout_mx_mspll_ccore); ret = clk_set_parent(dmc->mout_mclk_cdrex, dmc->mout_mx_mspll_ccore); if (ret) goto disable_clocks; /* * We are safe to increase the timings for current bypass frequency. * Thanks to this the settings will be ready for the upcoming clock * source change. */ exynos5_dram_change_timings(dmc, target_rate); clk_set_rate(dmc->fout_bpll, target_rate); ret = exynos5_switch_timing_regs(dmc, USE_BPLL_TIMINGS); if (ret) goto disable_clocks; ret = clk_set_parent(dmc->mout_mclk_cdrex, dmc->mout_bpll); if (ret) goto disable_clocks; /* * Make sure if the voltage is not from 'bypass' settings and align to * the right level for power efficiency. */ ret = exynos5_dmc_align_target_voltage(dmc, target_volt); disable_clocks: clk_disable_unprepare(dmc->mout_mx_mspll_ccore); clk_disable_unprepare(dmc->mout_spll); clk_disable_unprepare(dmc->fout_spll); return ret; } /** * exynos5_dmc_get_volt_freq() - Gets the frequency and voltage from the OPP * table. * @dmc: device for which the frequency is going to be changed * @freq: requested frequency in KHz * @target_rate: returned frequency which is the same or lower than * requested * @target_volt: returned voltage which corresponds to the returned * frequency * @flags: devfreq flags provided for this frequency change request * * Function gets requested frequency and checks OPP framework for needed * frequency and voltage. It populates the values 'target_rate' and * 'target_volt' or returns error value when OPP framework fails. */ static int exynos5_dmc_get_volt_freq(struct exynos5_dmc *dmc, unsigned long *freq, unsigned long *target_rate, unsigned long *target_volt, u32 flags) { struct dev_pm_opp *opp; opp = devfreq_recommended_opp(dmc->dev, freq, flags); if (IS_ERR(opp)) return PTR_ERR(opp); *target_rate = dev_pm_opp_get_freq(opp); *target_volt = dev_pm_opp_get_voltage(opp); dev_pm_opp_put(opp); return 0; } /** * exynos5_dmc_target() - Function responsible for changing frequency of DMC * @dev: device for which the frequency is going to be changed * @freq: requested frequency in KHz * @flags: flags provided for this frequency change request * * An entry function provided to the devfreq framework which provides frequency * change of the DMC. The function gets the possible rate from OPP table based * on requested frequency. It calls the next function responsible for the * frequency and voltage change. In case of failure, does not set 'curr_rate' * and returns error value to the framework. */ static int exynos5_dmc_target(struct device *dev, unsigned long *freq, u32 flags) { struct exynos5_dmc *dmc = dev_get_drvdata(dev); unsigned long target_rate = 0; unsigned long target_volt = 0; int ret; ret = exynos5_dmc_get_volt_freq(dmc, freq, &target_rate, &target_volt, flags); if (ret) return ret; if (target_rate == dmc->curr_rate) return 0; mutex_lock(&dmc->lock); ret = exynos5_dmc_change_freq_and_volt(dmc, target_rate, target_volt); if (ret) { mutex_unlock(&dmc->lock); return ret; } dmc->curr_rate = target_rate; mutex_unlock(&dmc->lock); return 0; } /** * exynos5_counters_get() - Gets the performance counters values. * @dmc: device for which the counters are going to be checked * @load_count: variable which is populated with counter value * @total_count: variable which is used as 'wall clock' reference * * Function which provides performance counters values. It sums up counters for * two DMC channels. The 'total_count' is used as a reference and max value. * The ratio 'load_count/total_count' shows the busy percentage [0%, 100%]. */ static int exynos5_counters_get(struct exynos5_dmc *dmc, unsigned long *load_count, unsigned long *total_count) { unsigned long total = 0; struct devfreq_event_data event; int ret, i; *load_count = 0; /* Take into account only read+write counters, but stop all */ for (i = 0; i < dmc->num_counters; i++) { if (!dmc->counter[i]) continue; ret = devfreq_event_get_event(dmc->counter[i], &event); if (ret < 0) return ret; *load_count += event.load_count; if (total < event.total_count) total = event.total_count; } *total_count = total; return 0; } /** * exynos5_dmc_start_perf_events() - Setup and start performance event counters * @dmc: device for which the counters are going to be checked * @beg_value: initial value for the counter * * Function which enables needed counters, interrupts and sets initial values * then starts the counters. */ static void exynos5_dmc_start_perf_events(struct exynos5_dmc *dmc, u32 beg_value) { /* Enable interrupts for counter 2 */ writel(PERF_CNT2, dmc->base_drexi0 + DREX_INTENS_PPC); writel(PERF_CNT2, dmc->base_drexi1 + DREX_INTENS_PPC); /* Enable counter 2 and CCNT */ writel(PERF_CNT2 | PERF_CCNT, dmc->base_drexi0 + DREX_CNTENS_PPC); writel(PERF_CNT2 | PERF_CCNT, dmc->base_drexi1 + DREX_CNTENS_PPC); /* Clear overflow flag for all counters */ writel(PERF_CNT2 | PERF_CCNT, dmc->base_drexi0 + DREX_FLAG_PPC); writel(PERF_CNT2 | PERF_CCNT, dmc->base_drexi1 + DREX_FLAG_PPC); /* Reset all counters */ writel(CC_RESET | PPC_COUNTER_RESET, dmc->base_drexi0 + DREX_PMNC_PPC); writel(CC_RESET | PPC_COUNTER_RESET, dmc->base_drexi1 + DREX_PMNC_PPC); /* * Set start value for the counters, the number of samples that * will be gathered is calculated as: 0xffffffff - beg_value */ writel(beg_value, dmc->base_drexi0 + DREX_PMCNT2_PPC); writel(beg_value, dmc->base_drexi1 + DREX_PMCNT2_PPC); /* Start all counters */ writel(PPC_ENABLE, dmc->base_drexi0 + DREX_PMNC_PPC); writel(PPC_ENABLE, dmc->base_drexi1 + DREX_PMNC_PPC); } /** * exynos5_dmc_perf_events_calc() - Calculate utilization * @dmc: device for which the counters are going to be checked * @diff_ts: time between last interrupt and current one * * Function which calculates needed utilization for the devfreq governor. * It prepares values for 'busy_time' and 'total_time' based on elapsed time * between interrupts, which approximates utilization. */ static void exynos5_dmc_perf_events_calc(struct exynos5_dmc *dmc, u64 diff_ts) { /* * This is a simple algorithm for managing traffic on DMC. * When there is almost no load the counters overflow every 4s, * no mater the DMC frequency. * The high load might be approximated using linear function. * Knowing that, simple calculation can provide 'busy_time' and * 'total_time' to the devfreq governor which picks up target * frequency. * We want a fast ramp up and slow decay in frequency change function. */ if (diff_ts < PERF_EVENT_UP_DOWN_THRESHOLD) { /* * Set higher utilization for the simple_ondemand governor. * The governor should increase the frequency of the DMC. */ dmc->load = 70; dmc->total = 100; } else { /* * Set low utilization for the simple_ondemand governor. * The governor should decrease the frequency of the DMC. */ dmc->load = 35; dmc->total = 100; } dev_dbg(dmc->dev, "diff_ts=%llu\n", diff_ts); } /** * exynos5_dmc_perf_events_check() - Checks the status of the counters * @dmc: device for which the counters are going to be checked * * Function which is called from threaded IRQ to check the counters state * and to call approximation for the needed utilization. */ static void exynos5_dmc_perf_events_check(struct exynos5_dmc *dmc) { u32 val; u64 diff_ts, ts; ts = ktime_get_ns(); /* Stop all counters */ writel(0, dmc->base_drexi0 + DREX_PMNC_PPC); writel(0, dmc->base_drexi1 + DREX_PMNC_PPC); /* Check the source in interrupt flag registers (which channel) */ val = readl(dmc->base_drexi0 + DREX_FLAG_PPC); if (val) { diff_ts = ts - dmc->last_overflow_ts[0]; dmc->last_overflow_ts[0] = ts; dev_dbg(dmc->dev, "drex0 0xE050 val= 0x%08x\n", val); } else { val = readl(dmc->base_drexi1 + DREX_FLAG_PPC); diff_ts = ts - dmc->last_overflow_ts[1]; dmc->last_overflow_ts[1] = ts; dev_dbg(dmc->dev, "drex1 0xE050 val= 0x%08x\n", val); } exynos5_dmc_perf_events_calc(dmc, diff_ts); exynos5_dmc_start_perf_events(dmc, PERF_COUNTER_START_VALUE); } /** * exynos5_dmc_enable_perf_events() - Enable performance events * @dmc: device for which the counters are going to be checked * * Function which is setup needed environment and enables counters. */ static void exynos5_dmc_enable_perf_events(struct exynos5_dmc *dmc) { u64 ts; /* Enable Performance Event Clock */ writel(PEREV_CLK_EN, dmc->base_drexi0 + DREX_PPCCLKCON); writel(PEREV_CLK_EN, dmc->base_drexi1 + DREX_PPCCLKCON); /* Select read transfers as performance event2 */ writel(READ_TRANSFER_CH0, dmc->base_drexi0 + DREX_PEREV2CONFIG); writel(READ_TRANSFER_CH1, dmc->base_drexi1 + DREX_PEREV2CONFIG); ts = ktime_get_ns(); dmc->last_overflow_ts[0] = ts; dmc->last_overflow_ts[1] = ts; /* Devfreq shouldn't be faster than initialization, play safe though. */ dmc->load = 99; dmc->total = 100; } /** * exynos5_dmc_disable_perf_events() - Disable performance events * @dmc: device for which the counters are going to be checked * * Function which stops, disables performance event counters and interrupts. */ static void exynos5_dmc_disable_perf_events(struct exynos5_dmc *dmc) { /* Stop all counters */ writel(0, dmc->base_drexi0 + DREX_PMNC_PPC); writel(0, dmc->base_drexi1 + DREX_PMNC_PPC); /* Disable interrupts for counter 2 */ writel(PERF_CNT2, dmc->base_drexi0 + DREX_INTENC_PPC); writel(PERF_CNT2, dmc->base_drexi1 + DREX_INTENC_PPC); /* Disable counter 2 and CCNT */ writel(PERF_CNT2 | PERF_CCNT, dmc->base_drexi0 + DREX_CNTENC_PPC); writel(PERF_CNT2 | PERF_CCNT, dmc->base_drexi1 + DREX_CNTENC_PPC); /* Clear overflow flag for all counters */ writel(PERF_CNT2 | PERF_CCNT, dmc->base_drexi0 + DREX_FLAG_PPC); writel(PERF_CNT2 | PERF_CCNT, dmc->base_drexi1 + DREX_FLAG_PPC); } /** * exynos5_dmc_get_status() - Read current DMC performance statistics. * @dev: device for which the statistics are requested * @stat: structure which has statistic fields * * Function reads the DMC performance counters and calculates 'busy_time' * and 'total_time'. To protect from overflow, the values are shifted right * by 10. After read out the counters are setup to count again. */ static int exynos5_dmc_get_status(struct device *dev, struct devfreq_dev_status *stat) { struct exynos5_dmc *dmc = dev_get_drvdata(dev); unsigned long load, total; int ret; if (dmc->in_irq_mode) { mutex_lock(&dmc->lock); stat->current_frequency = dmc->curr_rate; mutex_unlock(&dmc->lock); stat->busy_time = dmc->load; stat->total_time = dmc->total; } else { ret = exynos5_counters_get(dmc, &load, &total); if (ret < 0) return -EINVAL; /* To protect from overflow, divide by 1024 */ stat->busy_time = load >> 10; stat->total_time = total >> 10; ret = exynos5_counters_set_event(dmc); if (ret < 0) { dev_err(dev, "could not set event counter\n"); return ret; } } return 0; } /** * exynos5_dmc_get_cur_freq() - Function returns current DMC frequency * @dev: device for which the framework checks operating frequency * @freq: returned frequency value * * It returns the currently used frequency of the DMC. The real operating * frequency might be lower when the clock source value could not be divided * to the requested value. */ static int exynos5_dmc_get_cur_freq(struct device *dev, unsigned long *freq) { struct exynos5_dmc *dmc = dev_get_drvdata(dev); mutex_lock(&dmc->lock); *freq = dmc->curr_rate; mutex_unlock(&dmc->lock); return 0; } /* * exynos5_dmc_df_profile - Devfreq governor's profile structure * * It provides to the devfreq framework needed functions and polling period. */ static struct devfreq_dev_profile exynos5_dmc_df_profile = { .timer = DEVFREQ_TIMER_DELAYED, .target = exynos5_dmc_target, .get_dev_status = exynos5_dmc_get_status, .get_cur_freq = exynos5_dmc_get_cur_freq, }; /** * exynos5_dmc_align_init_freq() - Align initial frequency value * @dmc: device for which the frequency is going to be set * @bootloader_init_freq: initial frequency set by the bootloader in KHz * * The initial bootloader frequency, which is present during boot, might be * different that supported frequency values in the driver. It is possible * due to different PLL settings or used PLL as a source. * This function provides the 'initial_freq' for the devfreq framework * statistics engine which supports only registered values. Thus, some alignment * must be made. */ static unsigned long exynos5_dmc_align_init_freq(struct exynos5_dmc *dmc, unsigned long bootloader_init_freq) { unsigned long aligned_freq; int idx; idx = find_target_freq_idx(dmc, bootloader_init_freq); if (idx >= 0) aligned_freq = dmc->opp[idx].freq_hz; else aligned_freq = dmc->opp[dmc->opp_count - 1].freq_hz; return aligned_freq; } /** * create_timings_aligned() - Create register values and align with standard * @dmc: device for which the frequency is going to be set * @reg_timing_row: array to fill with values for timing row register * @reg_timing_data: array to fill with values for timing data register * @reg_timing_power: array to fill with values for timing power register * @clk_period_ps: the period of the clock, known as tCK * * The function calculates timings and creates a register value ready for * a frequency transition. The register contains a few timings. They are * shifted by a known offset. The timing value is calculated based on memory * specyfication: minimal time required and minimal cycles required. */ static int create_timings_aligned(struct exynos5_dmc *dmc, u32 *reg_timing_row, u32 *reg_timing_data, u32 *reg_timing_power, u32 clk_period_ps) { u32 val; const struct timing_reg *reg; if (clk_period_ps == 0) return -EINVAL; *reg_timing_row = 0; *reg_timing_data = 0; *reg_timing_power = 0; val = dmc->timings->tRFC / clk_period_ps; val += dmc->timings->tRFC % clk_period_ps ? 1 : 0; val = max(val, dmc->min_tck->tRFC); reg = &timing_row_reg_fields[0]; *reg_timing_row |= TIMING_VAL2REG(reg, val); val = dmc->timings->tRRD / clk_period_ps; val += dmc->timings->tRRD % clk_period_ps ? 1 : 0; val = max(val, dmc->min_tck->tRRD); reg = &timing_row_reg_fields[1]; *reg_timing_row |= TIMING_VAL2REG(reg, val); val = dmc->timings->tRPab / clk_period_ps; val += dmc->timings->tRPab % clk_period_ps ? 1 : 0; val = max(val, dmc->min_tck->tRPab); reg = &timing_row_reg_fields[2]; *reg_timing_row |= TIMING_VAL2REG(reg, val); val = dmc->timings->tRCD / clk_period_ps; val += dmc->timings->tRCD % clk_period_ps ? 1 : 0; val = max(val, dmc->min_tck->tRCD); reg = &timing_row_reg_fields[3]; *reg_timing_row |= TIMING_VAL2REG(reg, val); val = dmc->timings->tRC / clk_period_ps; val += dmc->timings->tRC % clk_period_ps ? 1 : 0; val = max(val, dmc->min_tck->tRC); reg = &timing_row_reg_fields[4]; *reg_timing_row |= TIMING_VAL2REG(reg, val); val = dmc->timings->tRAS / clk_period_ps; val += dmc->timings->tRAS % clk_period_ps ? 1 : 0; val = max(val, dmc->min_tck->tRAS); reg = &timing_row_reg_fields[5]; *reg_timing_row |= TIMING_VAL2REG(reg, val); /* data related timings */ val = dmc->timings->tWTR / clk_period_ps; val += dmc->timings->tWTR % clk_period_ps ? 1 : 0; val = max(val, dmc->min_tck->tWTR); reg = &timing_data_reg_fields[0]; *reg_timing_data |= TIMING_VAL2REG(reg, val); val = dmc->timings->tWR / clk_period_ps; val += dmc->timings->tWR % clk_period_ps ? 1 : 0; val = max(val, dmc->min_tck->tWR); reg = &timing_data_reg_fields[1]; *reg_timing_data |= TIMING_VAL2REG(reg, val); val = dmc->timings->tRTP / clk_period_ps; val += dmc->timings->tRTP % clk_period_ps ? 1 : 0; val = max(val, dmc->min_tck->tRTP); reg = &timing_data_reg_fields[2]; *reg_timing_data |= TIMING_VAL2REG(reg, val); val = dmc->timings->tW2W_C2C / clk_period_ps; val += dmc->timings->tW2W_C2C % clk_period_ps ? 1 : 0; val = max(val, dmc->min_tck->tW2W_C2C); reg = &timing_data_reg_fields[3]; *reg_timing_data |= TIMING_VAL2REG(reg, val); val = dmc->timings->tR2R_C2C / clk_period_ps; val += dmc->timings->tR2R_C2C % clk_period_ps ? 1 : 0; val = max(val, dmc->min_tck->tR2R_C2C); reg = &timing_data_reg_fields[4]; *reg_timing_data |= TIMING_VAL2REG(reg, val); val = dmc->timings->tWL / clk_period_ps; val += dmc->timings->tWL % clk_period_ps ? 1 : 0; val = max(val, dmc->min_tck->tWL); reg = &timing_data_reg_fields[5]; *reg_timing_data |= TIMING_VAL2REG(reg, val); val = dmc->timings->tDQSCK / clk_period_ps; val += dmc->timings->tDQSCK % clk_period_ps ? 1 : 0; val = max(val, dmc->min_tck->tDQSCK); reg = &timing_data_reg_fields[6]; *reg_timing_data |= TIMING_VAL2REG(reg, val); val = dmc->timings->tRL / clk_period_ps; val += dmc->timings->tRL % clk_period_ps ? 1 : 0; val = max(val, dmc->min_tck->tRL); reg = &timing_data_reg_fields[7]; *reg_timing_data |= TIMING_VAL2REG(reg, val); /* power related timings */ val = dmc->timings->tFAW / clk_period_ps; val += dmc->timings->tFAW % clk_period_ps ? 1 : 0; val = max(val, dmc->min_tck->tFAW); reg = &timing_power_reg_fields[0]; *reg_timing_power |= TIMING_VAL2REG(reg, val); val = dmc->timings->tXSR / clk_period_ps; val += dmc->timings->tXSR % clk_period_ps ? 1 : 0; val = max(val, dmc->min_tck->tXSR); reg = &timing_power_reg_fields[1]; *reg_timing_power |= TIMING_VAL2REG(reg, val); val = dmc->timings->tXP / clk_period_ps; val += dmc->timings->tXP % clk_period_ps ? 1 : 0; val = max(val, dmc->min_tck->tXP); reg = &timing_power_reg_fields[2]; *reg_timing_power |= TIMING_VAL2REG(reg, val); val = dmc->timings->tCKE / clk_period_ps; val += dmc->timings->tCKE % clk_period_ps ? 1 : 0; val = max(val, dmc->min_tck->tCKE); reg = &timing_power_reg_fields[3]; *reg_timing_power |= TIMING_VAL2REG(reg, val); val = dmc->timings->tMRD / clk_period_ps; val += dmc->timings->tMRD % clk_period_ps ? 1 : 0; val = max(val, dmc->min_tck->tMRD); reg = &timing_power_reg_fields[4]; *reg_timing_power |= TIMING_VAL2REG(reg, val); return 0; } /** * of_get_dram_timings() - helper function for parsing DT settings for DRAM * @dmc: device for which the frequency is going to be set * * The function parses DT entries with DRAM information. */ static int of_get_dram_timings(struct exynos5_dmc *dmc) { int ret = 0; int idx; struct device_node *np_ddr; u32 freq_mhz, clk_period_ps; np_ddr = of_parse_phandle(dmc->dev->of_node, "device-handle", 0); if (!np_ddr) { dev_warn(dmc->dev, "could not find 'device-handle' in DT\n"); return -EINVAL; } dmc->timing_row = devm_kmalloc_array(dmc->dev, TIMING_COUNT, sizeof(u32), GFP_KERNEL); if (!dmc->timing_row) { ret = -ENOMEM; goto put_node; } dmc->timing_data = devm_kmalloc_array(dmc->dev, TIMING_COUNT, sizeof(u32), GFP_KERNEL); if (!dmc->timing_data) { ret = -ENOMEM; goto put_node; } dmc->timing_power = devm_kmalloc_array(dmc->dev, TIMING_COUNT, sizeof(u32), GFP_KERNEL); if (!dmc->timing_power) { ret = -ENOMEM; goto put_node; } dmc->timings = of_lpddr3_get_ddr_timings(np_ddr, dmc->dev, DDR_TYPE_LPDDR3, &dmc->timings_arr_size); if (!dmc->timings) { dev_warn(dmc->dev, "could not get timings from DT\n"); ret = -EINVAL; goto put_node; } dmc->min_tck = of_lpddr3_get_min_tck(np_ddr, dmc->dev); if (!dmc->min_tck) { dev_warn(dmc->dev, "could not get tck from DT\n"); ret = -EINVAL; goto put_node; } /* Sorted array of OPPs with frequency ascending */ for (idx = 0; idx < dmc->opp_count; idx++) { freq_mhz = dmc->opp[idx].freq_hz / 1000000; clk_period_ps = 1000000 / freq_mhz; ret = create_timings_aligned(dmc, &dmc->timing_row[idx], &dmc->timing_data[idx], &dmc->timing_power[idx], clk_period_ps); } /* Take the highest frequency's timings as 'bypass' */ dmc->bypass_timing_row = dmc->timing_row[idx - 1]; dmc->bypass_timing_data = dmc->timing_data[idx - 1]; dmc->bypass_timing_power = dmc->timing_power[idx - 1]; put_node: of_node_put(np_ddr); return ret; } /** * exynos5_dmc_init_clks() - Initialize clocks needed for DMC operation. * @dmc: DMC structure containing needed fields * * Get the needed clocks defined in DT device, enable and set the right parents. * Read current frequency and initialize the initial rate for governor. */ static int exynos5_dmc_init_clks(struct exynos5_dmc *dmc) { int ret; unsigned long target_volt = 0; unsigned long target_rate = 0; unsigned int tmp; dmc->fout_spll = devm_clk_get(dmc->dev, "fout_spll"); if (IS_ERR(dmc->fout_spll)) return PTR_ERR(dmc->fout_spll); dmc->fout_bpll = devm_clk_get(dmc->dev, "fout_bpll"); if (IS_ERR(dmc->fout_bpll)) return PTR_ERR(dmc->fout_bpll); dmc->mout_mclk_cdrex = devm_clk_get(dmc->dev, "mout_mclk_cdrex"); if (IS_ERR(dmc->mout_mclk_cdrex)) return PTR_ERR(dmc->mout_mclk_cdrex); dmc->mout_bpll = devm_clk_get(dmc->dev, "mout_bpll"); if (IS_ERR(dmc->mout_bpll)) return PTR_ERR(dmc->mout_bpll); dmc->mout_mx_mspll_ccore = devm_clk_get(dmc->dev, "mout_mx_mspll_ccore"); if (IS_ERR(dmc->mout_mx_mspll_ccore)) return PTR_ERR(dmc->mout_mx_mspll_ccore); dmc->mout_spll = devm_clk_get(dmc->dev, "ff_dout_spll2"); if (IS_ERR(dmc->mout_spll)) { dmc->mout_spll = devm_clk_get(dmc->dev, "mout_sclk_spll"); if (IS_ERR(dmc->mout_spll)) return PTR_ERR(dmc->mout_spll); } /* * Convert frequency to KHz values and set it for the governor. */ dmc->curr_rate = clk_get_rate(dmc->mout_mclk_cdrex); dmc->curr_rate = exynos5_dmc_align_init_freq(dmc, dmc->curr_rate); exynos5_dmc_df_profile.initial_freq = dmc->curr_rate; ret = exynos5_dmc_get_volt_freq(dmc, &dmc->curr_rate, &target_rate, &target_volt, 0); if (ret) return ret; dmc->curr_volt = target_volt; ret = clk_set_parent(dmc->mout_mx_mspll_ccore, dmc->mout_spll); if (ret) return ret; clk_prepare_enable(dmc->fout_bpll); clk_prepare_enable(dmc->mout_bpll); /* * Some bootloaders do not set clock routes correctly. * Stop one path in clocks to PHY. */ regmap_read(dmc->clk_regmap, CDREX_LPDDR3PHY_CLKM_SRC, &tmp); tmp &= ~(BIT(1) | BIT(0)); regmap_write(dmc->clk_regmap, CDREX_LPDDR3PHY_CLKM_SRC, tmp); return 0; } /** * exynos5_performance_counters_init() - Initializes performance DMC's counters * @dmc: DMC for which it does the setup * * Initialization of performance counters in DMC for estimating usage. * The counter's values are used for calculation of a memory bandwidth and based * on that the governor changes the frequency. * The counters are not used when the governor is GOVERNOR_USERSPACE. */ static int exynos5_performance_counters_init(struct exynos5_dmc *dmc) { int ret, i; dmc->num_counters = devfreq_event_get_edev_count(dmc->dev, "devfreq-events"); if (dmc->num_counters < 0) { dev_err(dmc->dev, "could not get devfreq-event counters\n"); return dmc->num_counters; } dmc->counter = devm_kcalloc(dmc->dev, dmc->num_counters, sizeof(*dmc->counter), GFP_KERNEL); if (!dmc->counter) return -ENOMEM; for (i = 0; i < dmc->num_counters; i++) { dmc->counter[i] = devfreq_event_get_edev_by_phandle(dmc->dev, "devfreq-events", i); if (IS_ERR_OR_NULL(dmc->counter[i])) return -EPROBE_DEFER; } ret = exynos5_counters_enable_edev(dmc); if (ret < 0) { dev_err(dmc->dev, "could not enable event counter\n"); return ret; } ret = exynos5_counters_set_event(dmc); if (ret < 0) { exynos5_counters_disable_edev(dmc); dev_err(dmc->dev, "could not set event counter\n"); return ret; } return 0; } /** * exynos5_dmc_set_pause_on_switching() - Controls a pause feature in DMC * @dmc: device which is used for changing this feature * * There is a need of pausing DREX DMC when divider or MUX in clock tree * changes its configuration. In such situation access to the memory is blocked * in DMC automatically. This feature is used when clock frequency change * request appears and touches clock tree. */ static inline int exynos5_dmc_set_pause_on_switching(struct exynos5_dmc *dmc) { unsigned int val; int ret; ret = regmap_read(dmc->clk_regmap, CDREX_PAUSE, &val); if (ret) return ret; val |= 1UL; regmap_write(dmc->clk_regmap, CDREX_PAUSE, val); return 0; } static irqreturn_t dmc_irq_thread(int irq, void *priv) { int res; struct exynos5_dmc *dmc = priv; mutex_lock(&dmc->df->lock); exynos5_dmc_perf_events_check(dmc); res = update_devfreq(dmc->df); mutex_unlock(&dmc->df->lock); if (res) dev_warn(dmc->dev, "devfreq failed with %d\n", res); return IRQ_HANDLED; } /** * exynos5_dmc_probe() - Probe function for the DMC driver * @pdev: platform device for which the driver is going to be initialized * * Initialize basic components: clocks, regulators, performance counters, etc. * Read out product version and based on the information setup * internal structures for the controller (frequency and voltage) and for DRAM * memory parameters: timings for each operating frequency. * Register new devfreq device for controlling DVFS of the DMC. */ static int exynos5_dmc_probe(struct platform_device *pdev) { int ret = 0; struct device *dev = &pdev->dev; struct device_node *np = dev->of_node; struct exynos5_dmc *dmc; int irq[2]; dmc = devm_kzalloc(dev, sizeof(*dmc), GFP_KERNEL); if (!dmc) return -ENOMEM; mutex_init(&dmc->lock); dmc->dev = dev; platform_set_drvdata(pdev, dmc); dmc->base_drexi0 = devm_platform_ioremap_resource(pdev, 0); if (IS_ERR(dmc->base_drexi0)) return PTR_ERR(dmc->base_drexi0); dmc->base_drexi1 = devm_platform_ioremap_resource(pdev, 1); if (IS_ERR(dmc->base_drexi1)) return PTR_ERR(dmc->base_drexi1); dmc->clk_regmap = syscon_regmap_lookup_by_phandle(np, "samsung,syscon-clk"); if (IS_ERR(dmc->clk_regmap)) return PTR_ERR(dmc->clk_regmap); ret = exynos5_init_freq_table(dmc, &exynos5_dmc_df_profile); if (ret) { dev_warn(dev, "couldn't initialize frequency settings\n"); return ret; } dmc->vdd_mif = devm_regulator_get(dev, "vdd"); if (IS_ERR(dmc->vdd_mif)) { ret = PTR_ERR(dmc->vdd_mif); return ret; } ret = exynos5_dmc_init_clks(dmc); if (ret) return ret; ret = of_get_dram_timings(dmc); if (ret) { dev_warn(dev, "couldn't initialize timings settings\n"); goto remove_clocks; } ret = exynos5_dmc_set_pause_on_switching(dmc); if (ret) { dev_warn(dev, "couldn't get access to PAUSE register\n"); goto remove_clocks; } /* There is two modes in which the driver works: polling or IRQ */ irq[0] = platform_get_irq_byname(pdev, "drex_0"); irq[1] = platform_get_irq_byname(pdev, "drex_1"); if (irq[0] > 0 && irq[1] > 0 && irqmode) { ret = devm_request_threaded_irq(dev, irq[0], NULL, dmc_irq_thread, IRQF_ONESHOT, dev_name(dev), dmc); if (ret) { dev_err(dev, "couldn't grab IRQ\n"); goto remove_clocks; } ret = devm_request_threaded_irq(dev, irq[1], NULL, dmc_irq_thread, IRQF_ONESHOT, dev_name(dev), dmc); if (ret) { dev_err(dev, "couldn't grab IRQ\n"); goto remove_clocks; } /* * Setup default thresholds for the devfreq governor. * The values are chosen based on experiments. */ dmc->gov_data.upthreshold = 55; dmc->gov_data.downdifferential = 5; exynos5_dmc_enable_perf_events(dmc); dmc->in_irq_mode = 1; } else { ret = exynos5_performance_counters_init(dmc); if (ret) { dev_warn(dev, "couldn't probe performance counters\n"); goto remove_clocks; } /* * Setup default thresholds for the devfreq governor. * The values are chosen based on experiments. */ dmc->gov_data.upthreshold = 10; dmc->gov_data.downdifferential = 5; exynos5_dmc_df_profile.polling_ms = 100; } dmc->df = devm_devfreq_add_device(dev, &exynos5_dmc_df_profile, DEVFREQ_GOV_SIMPLE_ONDEMAND, &dmc->gov_data); if (IS_ERR(dmc->df)) { ret = PTR_ERR(dmc->df); goto err_devfreq_add; } if (dmc->in_irq_mode) exynos5_dmc_start_perf_events(dmc, PERF_COUNTER_START_VALUE); dev_info(dev, "DMC initialized, in irq mode: %d\n", dmc->in_irq_mode); return 0; err_devfreq_add: if (dmc->in_irq_mode) exynos5_dmc_disable_perf_events(dmc); else exynos5_counters_disable_edev(dmc); remove_clocks: clk_disable_unprepare(dmc->mout_bpll); clk_disable_unprepare(dmc->fout_bpll); return ret; } /** * exynos5_dmc_remove() - Remove function for the platform device * @pdev: platform device which is going to be removed * * The function relies on 'devm' framework function which automatically * clean the device's resources. It just calls explicitly disable function for * the performance counters. */ static void exynos5_dmc_remove(struct platform_device *pdev) { struct exynos5_dmc *dmc = dev_get_drvdata(&pdev->dev); if (dmc->in_irq_mode) exynos5_dmc_disable_perf_events(dmc); else exynos5_counters_disable_edev(dmc); clk_disable_unprepare(dmc->mout_bpll); clk_disable_unprepare(dmc->fout_bpll); } static const struct of_device_id exynos5_dmc_of_match[] = { { .compatible = "samsung,exynos5422-dmc", }, { }, }; MODULE_DEVICE_TABLE(of, exynos5_dmc_of_match); static struct platform_driver exynos5_dmc_platdrv = { .probe = exynos5_dmc_probe, .remove_new = exynos5_dmc_remove, .driver = { .name = "exynos5-dmc", .of_match_table = exynos5_dmc_of_match, }, }; module_platform_driver(exynos5_dmc_platdrv); MODULE_DESCRIPTION("Driver for Exynos5422 Dynamic Memory Controller dynamic frequency and voltage change"); MODULE_LICENSE("GPL v2"); MODULE_AUTHOR("Lukasz Luba");
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