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Diffstat (limited to 'drivers/cpufreq/armada-37xx-cpufreq.c')
-rw-r--r--drivers/cpufreq/armada-37xx-cpufreq.c547
1 files changed, 547 insertions, 0 deletions
diff --git a/drivers/cpufreq/armada-37xx-cpufreq.c b/drivers/cpufreq/armada-37xx-cpufreq.c
new file mode 100644
index 000000000..f0be8a43e
--- /dev/null
+++ b/drivers/cpufreq/armada-37xx-cpufreq.c
@@ -0,0 +1,547 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * CPU frequency scaling support for Armada 37xx platform.
+ *
+ * Copyright (C) 2017 Marvell
+ *
+ * Gregory CLEMENT <gregory.clement@free-electrons.com>
+ */
+
+#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/mfd/syscon.h>
+#include <linux/module.h>
+#include <linux/of_address.h>
+#include <linux/of_device.h>
+#include <linux/of_irq.h>
+#include <linux/platform_device.h>
+#include <linux/pm_opp.h>
+#include <linux/regmap.h>
+#include <linux/slab.h>
+
+#include "cpufreq-dt.h"
+
+/* Clk register set */
+#define ARMADA_37XX_CLK_TBG_SEL 0
+#define ARMADA_37XX_CLK_TBG_SEL_CPU_OFF 22
+
+/* Power management in North Bridge register set */
+#define ARMADA_37XX_NB_L0L1 0x18
+#define ARMADA_37XX_NB_L2L3 0x1C
+#define ARMADA_37XX_NB_TBG_DIV_OFF 13
+#define ARMADA_37XX_NB_TBG_DIV_MASK 0x7
+#define ARMADA_37XX_NB_CLK_SEL_OFF 11
+#define ARMADA_37XX_NB_CLK_SEL_MASK 0x1
+#define ARMADA_37XX_NB_CLK_SEL_TBG 0x1
+#define ARMADA_37XX_NB_TBG_SEL_OFF 9
+#define ARMADA_37XX_NB_TBG_SEL_MASK 0x3
+#define ARMADA_37XX_NB_VDD_SEL_OFF 6
+#define ARMADA_37XX_NB_VDD_SEL_MASK 0x3
+#define ARMADA_37XX_NB_CONFIG_SHIFT 16
+#define ARMADA_37XX_NB_DYN_MOD 0x24
+#define ARMADA_37XX_NB_CLK_SEL_EN BIT(26)
+#define ARMADA_37XX_NB_TBG_EN BIT(28)
+#define ARMADA_37XX_NB_DIV_EN BIT(29)
+#define ARMADA_37XX_NB_VDD_EN BIT(30)
+#define ARMADA_37XX_NB_DFS_EN BIT(31)
+#define ARMADA_37XX_NB_CPU_LOAD 0x30
+#define ARMADA_37XX_NB_CPU_LOAD_MASK 0x3
+#define ARMADA_37XX_DVFS_LOAD_0 0
+#define ARMADA_37XX_DVFS_LOAD_1 1
+#define ARMADA_37XX_DVFS_LOAD_2 2
+#define ARMADA_37XX_DVFS_LOAD_3 3
+
+/* AVS register set */
+#define ARMADA_37XX_AVS_CTL0 0x0
+#define ARMADA_37XX_AVS_ENABLE BIT(30)
+#define ARMADA_37XX_AVS_HIGH_VDD_LIMIT 16
+#define ARMADA_37XX_AVS_LOW_VDD_LIMIT 22
+#define ARMADA_37XX_AVS_VDD_MASK 0x3F
+#define ARMADA_37XX_AVS_CTL2 0x8
+#define ARMADA_37XX_AVS_LOW_VDD_EN BIT(6)
+#define ARMADA_37XX_AVS_VSET(x) (0x1C + 4 * (x))
+
+/*
+ * On Armada 37xx the Power management manages 4 level of CPU load,
+ * each level can be associated with a CPU clock source, a CPU
+ * divider, a VDD level, etc...
+ */
+#define LOAD_LEVEL_NR 4
+
+#define MIN_VOLT_MV 1000
+#define MIN_VOLT_MV_FOR_L1_1000MHZ 1108
+#define MIN_VOLT_MV_FOR_L1_1200MHZ 1155
+
+/* AVS value for the corresponding voltage (in mV) */
+static int avs_map[] = {
+ 747, 758, 770, 782, 793, 805, 817, 828, 840, 852, 863, 875, 887, 898,
+ 910, 922, 933, 945, 957, 968, 980, 992, 1003, 1015, 1027, 1038, 1050,
+ 1062, 1073, 1085, 1097, 1108, 1120, 1132, 1143, 1155, 1167, 1178, 1190,
+ 1202, 1213, 1225, 1237, 1248, 1260, 1272, 1283, 1295, 1307, 1318, 1330,
+ 1342
+};
+
+struct armada37xx_cpufreq_state {
+ struct regmap *regmap;
+ u32 nb_l0l1;
+ u32 nb_l2l3;
+ u32 nb_dyn_mod;
+ u32 nb_cpu_load;
+};
+
+static struct armada37xx_cpufreq_state *armada37xx_cpufreq_state;
+
+struct armada_37xx_dvfs {
+ u32 cpu_freq_max;
+ u8 divider[LOAD_LEVEL_NR];
+ u32 avs[LOAD_LEVEL_NR];
+};
+
+static struct armada_37xx_dvfs armada_37xx_dvfs[] = {
+ /*
+ * The cpufreq scaling for 1.2 GHz variant of the SOC is currently
+ * unstable because we do not know how to configure it properly.
+ */
+ /* {.cpu_freq_max = 1200*1000*1000, .divider = {1, 2, 4, 6} }, */
+ {.cpu_freq_max = 1000*1000*1000, .divider = {1, 2, 4, 5} },
+ {.cpu_freq_max = 800*1000*1000, .divider = {1, 2, 3, 4} },
+ {.cpu_freq_max = 600*1000*1000, .divider = {2, 4, 5, 6} },
+};
+
+static struct armada_37xx_dvfs *armada_37xx_cpu_freq_info_get(u32 freq)
+{
+ int i;
+
+ for (i = 0; i < ARRAY_SIZE(armada_37xx_dvfs); i++) {
+ if (freq == armada_37xx_dvfs[i].cpu_freq_max)
+ return &armada_37xx_dvfs[i];
+ }
+
+ pr_err("Unsupported CPU frequency %d MHz\n", freq/1000000);
+ return NULL;
+}
+
+/*
+ * Setup the four level managed by the hardware. Once the four level
+ * will be configured then the DVFS will be enabled.
+ */
+static void __init armada37xx_cpufreq_dvfs_setup(struct regmap *base,
+ struct regmap *clk_base, u8 *divider)
+{
+ u32 cpu_tbg_sel;
+ int load_lvl;
+
+ /* Determine to which TBG clock is CPU connected */
+ regmap_read(clk_base, ARMADA_37XX_CLK_TBG_SEL, &cpu_tbg_sel);
+ cpu_tbg_sel >>= ARMADA_37XX_CLK_TBG_SEL_CPU_OFF;
+ cpu_tbg_sel &= ARMADA_37XX_NB_TBG_SEL_MASK;
+
+ for (load_lvl = 0; load_lvl < LOAD_LEVEL_NR; load_lvl++) {
+ unsigned int reg, mask, val, offset = 0;
+
+ if (load_lvl <= ARMADA_37XX_DVFS_LOAD_1)
+ reg = ARMADA_37XX_NB_L0L1;
+ else
+ reg = ARMADA_37XX_NB_L2L3;
+
+ if (load_lvl == ARMADA_37XX_DVFS_LOAD_0 ||
+ load_lvl == ARMADA_37XX_DVFS_LOAD_2)
+ offset += ARMADA_37XX_NB_CONFIG_SHIFT;
+
+ /* Set cpu clock source, for all the level we use TBG */
+ val = ARMADA_37XX_NB_CLK_SEL_TBG << ARMADA_37XX_NB_CLK_SEL_OFF;
+ mask = (ARMADA_37XX_NB_CLK_SEL_MASK
+ << ARMADA_37XX_NB_CLK_SEL_OFF);
+
+ /* Set TBG index, for all levels we use the same TBG */
+ val = cpu_tbg_sel << ARMADA_37XX_NB_TBG_SEL_OFF;
+ mask = (ARMADA_37XX_NB_TBG_SEL_MASK
+ << ARMADA_37XX_NB_TBG_SEL_OFF);
+
+ /*
+ * Set cpu divider based on the pre-computed array in
+ * order to have balanced step.
+ */
+ val |= divider[load_lvl] << ARMADA_37XX_NB_TBG_DIV_OFF;
+ mask |= (ARMADA_37XX_NB_TBG_DIV_MASK
+ << ARMADA_37XX_NB_TBG_DIV_OFF);
+
+ /* Set VDD divider which is actually the load level. */
+ val |= load_lvl << ARMADA_37XX_NB_VDD_SEL_OFF;
+ mask |= (ARMADA_37XX_NB_VDD_SEL_MASK
+ << ARMADA_37XX_NB_VDD_SEL_OFF);
+
+ val <<= offset;
+ mask <<= offset;
+
+ regmap_update_bits(base, reg, mask, val);
+ }
+}
+
+/*
+ * Find out the armada 37x supported AVS value whose voltage value is
+ * the round-up closest to the target voltage value.
+ */
+static u32 armada_37xx_avs_val_match(int target_vm)
+{
+ u32 avs;
+
+ /* Find out the round-up closest supported voltage value */
+ for (avs = 0; avs < ARRAY_SIZE(avs_map); avs++)
+ if (avs_map[avs] >= target_vm)
+ break;
+
+ /*
+ * If all supported voltages are smaller than target one,
+ * choose the largest supported voltage
+ */
+ if (avs == ARRAY_SIZE(avs_map))
+ avs = ARRAY_SIZE(avs_map) - 1;
+
+ return avs;
+}
+
+/*
+ * For Armada 37xx soc, L0(VSET0) VDD AVS value is set to SVC revision
+ * value or a default value when SVC is not supported.
+ * - L0 can be read out from the register of AVS_CTRL_0 and L0 voltage
+ * can be got from the mapping table of avs_map.
+ * - L1 voltage should be about 100mv smaller than L0 voltage
+ * - L2 & L3 voltage should be about 150mv smaller than L0 voltage.
+ * This function calculates L1 & L2 & L3 AVS values dynamically based
+ * on L0 voltage and fill all AVS values to the AVS value table.
+ * When base CPU frequency is 1000 or 1200 MHz then there is additional
+ * minimal avs value for load L1.
+ */
+static void __init armada37xx_cpufreq_avs_configure(struct regmap *base,
+ struct armada_37xx_dvfs *dvfs)
+{
+ unsigned int target_vm;
+ int load_level = 0;
+ u32 l0_vdd_min;
+
+ if (base == NULL)
+ return;
+
+ /* Get L0 VDD min value */
+ regmap_read(base, ARMADA_37XX_AVS_CTL0, &l0_vdd_min);
+ l0_vdd_min = (l0_vdd_min >> ARMADA_37XX_AVS_LOW_VDD_LIMIT) &
+ ARMADA_37XX_AVS_VDD_MASK;
+ if (l0_vdd_min >= ARRAY_SIZE(avs_map)) {
+ pr_err("L0 VDD MIN %d is not correct.\n", l0_vdd_min);
+ return;
+ }
+ dvfs->avs[0] = l0_vdd_min;
+
+ if (avs_map[l0_vdd_min] <= MIN_VOLT_MV) {
+ /*
+ * If L0 voltage is smaller than 1000mv, then all VDD sets
+ * use L0 voltage;
+ */
+ u32 avs_min = armada_37xx_avs_val_match(MIN_VOLT_MV);
+
+ for (load_level = 1; load_level < LOAD_LEVEL_NR; load_level++)
+ dvfs->avs[load_level] = avs_min;
+
+ /*
+ * Set the avs values for load L0 and L1 when base CPU frequency
+ * is 1000/1200 MHz to its typical initial values according to
+ * the Armada 3700 Hardware Specifications.
+ */
+ if (dvfs->cpu_freq_max >= 1000*1000*1000) {
+ if (dvfs->cpu_freq_max >= 1200*1000*1000)
+ avs_min = armada_37xx_avs_val_match(MIN_VOLT_MV_FOR_L1_1200MHZ);
+ else
+ avs_min = armada_37xx_avs_val_match(MIN_VOLT_MV_FOR_L1_1000MHZ);
+ dvfs->avs[0] = dvfs->avs[1] = avs_min;
+ }
+
+ return;
+ }
+
+ /*
+ * L1 voltage is equal to L0 voltage - 100mv and it must be
+ * larger than 1000mv
+ */
+
+ target_vm = avs_map[l0_vdd_min] - 100;
+ target_vm = target_vm > MIN_VOLT_MV ? target_vm : MIN_VOLT_MV;
+ dvfs->avs[1] = armada_37xx_avs_val_match(target_vm);
+
+ /*
+ * L2 & L3 voltage is equal to L0 voltage - 150mv and it must
+ * be larger than 1000mv
+ */
+ target_vm = avs_map[l0_vdd_min] - 150;
+ target_vm = target_vm > MIN_VOLT_MV ? target_vm : MIN_VOLT_MV;
+ dvfs->avs[2] = dvfs->avs[3] = armada_37xx_avs_val_match(target_vm);
+
+ /*
+ * Fix the avs value for load L1 when base CPU frequency is 1000/1200 MHz,
+ * otherwise the CPU gets stuck when switching from load L1 to load L0.
+ * Also ensure that avs value for load L1 is not higher than for L0.
+ */
+ if (dvfs->cpu_freq_max >= 1000*1000*1000) {
+ u32 avs_min_l1;
+
+ if (dvfs->cpu_freq_max >= 1200*1000*1000)
+ avs_min_l1 = armada_37xx_avs_val_match(MIN_VOLT_MV_FOR_L1_1200MHZ);
+ else
+ avs_min_l1 = armada_37xx_avs_val_match(MIN_VOLT_MV_FOR_L1_1000MHZ);
+
+ if (avs_min_l1 > dvfs->avs[0])
+ avs_min_l1 = dvfs->avs[0];
+
+ if (dvfs->avs[1] < avs_min_l1)
+ dvfs->avs[1] = avs_min_l1;
+ }
+}
+
+static void __init armada37xx_cpufreq_avs_setup(struct regmap *base,
+ struct armada_37xx_dvfs *dvfs)
+{
+ unsigned int avs_val = 0;
+ int load_level = 0;
+
+ if (base == NULL)
+ return;
+
+ /* Disable AVS before the configuration */
+ regmap_update_bits(base, ARMADA_37XX_AVS_CTL0,
+ ARMADA_37XX_AVS_ENABLE, 0);
+
+
+ /* Enable low voltage mode */
+ regmap_update_bits(base, ARMADA_37XX_AVS_CTL2,
+ ARMADA_37XX_AVS_LOW_VDD_EN,
+ ARMADA_37XX_AVS_LOW_VDD_EN);
+
+
+ for (load_level = 1; load_level < LOAD_LEVEL_NR; load_level++) {
+ avs_val = dvfs->avs[load_level];
+ regmap_update_bits(base, ARMADA_37XX_AVS_VSET(load_level-1),
+ ARMADA_37XX_AVS_VDD_MASK << ARMADA_37XX_AVS_HIGH_VDD_LIMIT |
+ ARMADA_37XX_AVS_VDD_MASK << ARMADA_37XX_AVS_LOW_VDD_LIMIT,
+ avs_val << ARMADA_37XX_AVS_HIGH_VDD_LIMIT |
+ avs_val << ARMADA_37XX_AVS_LOW_VDD_LIMIT);
+ }
+
+ /* Enable AVS after the configuration */
+ regmap_update_bits(base, ARMADA_37XX_AVS_CTL0,
+ ARMADA_37XX_AVS_ENABLE,
+ ARMADA_37XX_AVS_ENABLE);
+
+}
+
+static void armada37xx_cpufreq_disable_dvfs(struct regmap *base)
+{
+ unsigned int reg = ARMADA_37XX_NB_DYN_MOD,
+ mask = ARMADA_37XX_NB_DFS_EN;
+
+ regmap_update_bits(base, reg, mask, 0);
+}
+
+static void __init armada37xx_cpufreq_enable_dvfs(struct regmap *base)
+{
+ unsigned int val, reg = ARMADA_37XX_NB_CPU_LOAD,
+ mask = ARMADA_37XX_NB_CPU_LOAD_MASK;
+
+ /* Start with the highest load (0) */
+ val = ARMADA_37XX_DVFS_LOAD_0;
+ regmap_update_bits(base, reg, mask, val);
+
+ /* Now enable DVFS for the CPUs */
+ reg = ARMADA_37XX_NB_DYN_MOD;
+ mask = ARMADA_37XX_NB_CLK_SEL_EN | ARMADA_37XX_NB_TBG_EN |
+ ARMADA_37XX_NB_DIV_EN | ARMADA_37XX_NB_VDD_EN |
+ ARMADA_37XX_NB_DFS_EN;
+
+ regmap_update_bits(base, reg, mask, mask);
+}
+
+static int armada37xx_cpufreq_suspend(struct cpufreq_policy *policy)
+{
+ struct armada37xx_cpufreq_state *state = armada37xx_cpufreq_state;
+
+ regmap_read(state->regmap, ARMADA_37XX_NB_L0L1, &state->nb_l0l1);
+ regmap_read(state->regmap, ARMADA_37XX_NB_L2L3, &state->nb_l2l3);
+ regmap_read(state->regmap, ARMADA_37XX_NB_CPU_LOAD,
+ &state->nb_cpu_load);
+ regmap_read(state->regmap, ARMADA_37XX_NB_DYN_MOD, &state->nb_dyn_mod);
+
+ return 0;
+}
+
+static int armada37xx_cpufreq_resume(struct cpufreq_policy *policy)
+{
+ struct armada37xx_cpufreq_state *state = armada37xx_cpufreq_state;
+
+ /* Ensure DVFS is disabled otherwise the following registers are RO */
+ armada37xx_cpufreq_disable_dvfs(state->regmap);
+
+ regmap_write(state->regmap, ARMADA_37XX_NB_L0L1, state->nb_l0l1);
+ regmap_write(state->regmap, ARMADA_37XX_NB_L2L3, state->nb_l2l3);
+ regmap_write(state->regmap, ARMADA_37XX_NB_CPU_LOAD,
+ state->nb_cpu_load);
+
+ /*
+ * NB_DYN_MOD register is the one that actually enable back DVFS if it
+ * was enabled before the suspend operation. This must be done last
+ * otherwise other registers are not writable.
+ */
+ regmap_write(state->regmap, ARMADA_37XX_NB_DYN_MOD, state->nb_dyn_mod);
+
+ return 0;
+}
+
+static int __init armada37xx_cpufreq_driver_init(void)
+{
+ struct cpufreq_dt_platform_data pdata;
+ struct armada_37xx_dvfs *dvfs;
+ struct platform_device *pdev;
+ unsigned long freq;
+ unsigned int cur_frequency, base_frequency;
+ struct regmap *nb_clk_base, *nb_pm_base, *avs_base;
+ struct device *cpu_dev;
+ int load_lvl, ret;
+ struct clk *clk, *parent;
+
+ nb_clk_base =
+ syscon_regmap_lookup_by_compatible("marvell,armada-3700-periph-clock-nb");
+ if (IS_ERR(nb_clk_base))
+ return -ENODEV;
+
+ nb_pm_base =
+ syscon_regmap_lookup_by_compatible("marvell,armada-3700-nb-pm");
+
+ if (IS_ERR(nb_pm_base))
+ return -ENODEV;
+
+ avs_base =
+ syscon_regmap_lookup_by_compatible("marvell,armada-3700-avs");
+
+ /* if AVS is not present don't use it but still try to setup dvfs */
+ if (IS_ERR(avs_base)) {
+ pr_info("Syscon failed for Adapting Voltage Scaling: skip it\n");
+ avs_base = NULL;
+ }
+ /* Before doing any configuration on the DVFS first, disable it */
+ armada37xx_cpufreq_disable_dvfs(nb_pm_base);
+
+ /*
+ * On CPU 0 register the operating points supported (which are
+ * the nominal CPU frequency and full integer divisions of
+ * it).
+ */
+ cpu_dev = get_cpu_device(0);
+ if (!cpu_dev) {
+ dev_err(cpu_dev, "Cannot get CPU\n");
+ return -ENODEV;
+ }
+
+ clk = clk_get(cpu_dev, NULL);
+ if (IS_ERR(clk)) {
+ dev_err(cpu_dev, "Cannot get clock for CPU0\n");
+ return PTR_ERR(clk);
+ }
+
+ parent = clk_get_parent(clk);
+ if (IS_ERR(parent)) {
+ dev_err(cpu_dev, "Cannot get parent clock for CPU0\n");
+ clk_put(clk);
+ return PTR_ERR(parent);
+ }
+
+ /* Get parent CPU frequency */
+ base_frequency = clk_get_rate(parent);
+
+ if (!base_frequency) {
+ dev_err(cpu_dev, "Failed to get parent clock rate for CPU\n");
+ clk_put(clk);
+ return -EINVAL;
+ }
+
+ /* Get nominal (current) CPU frequency */
+ cur_frequency = clk_get_rate(clk);
+ if (!cur_frequency) {
+ dev_err(cpu_dev, "Failed to get clock rate for CPU\n");
+ clk_put(clk);
+ return -EINVAL;
+ }
+
+ dvfs = armada_37xx_cpu_freq_info_get(base_frequency);
+ if (!dvfs) {
+ clk_put(clk);
+ return -EINVAL;
+ }
+
+ armada37xx_cpufreq_state = kmalloc(sizeof(*armada37xx_cpufreq_state),
+ GFP_KERNEL);
+ if (!armada37xx_cpufreq_state) {
+ clk_put(clk);
+ return -ENOMEM;
+ }
+
+ armada37xx_cpufreq_state->regmap = nb_pm_base;
+
+ armada37xx_cpufreq_avs_configure(avs_base, dvfs);
+ armada37xx_cpufreq_avs_setup(avs_base, dvfs);
+
+ armada37xx_cpufreq_dvfs_setup(nb_pm_base, nb_clk_base, dvfs->divider);
+ clk_put(clk);
+
+ for (load_lvl = ARMADA_37XX_DVFS_LOAD_0; load_lvl < LOAD_LEVEL_NR;
+ load_lvl++) {
+ unsigned long u_volt = avs_map[dvfs->avs[load_lvl]] * 1000;
+ freq = base_frequency / dvfs->divider[load_lvl];
+ ret = dev_pm_opp_add(cpu_dev, freq, u_volt);
+ if (ret)
+ goto remove_opp;
+
+
+ }
+
+ /* Now that everything is setup, enable the DVFS at hardware level */
+ armada37xx_cpufreq_enable_dvfs(nb_pm_base);
+
+ memset(&pdata, 0, sizeof(pdata));
+ pdata.suspend = armada37xx_cpufreq_suspend;
+ pdata.resume = armada37xx_cpufreq_resume;
+
+ pdev = platform_device_register_data(NULL, "cpufreq-dt", -1, &pdata,
+ sizeof(pdata));
+ ret = PTR_ERR_OR_ZERO(pdev);
+ if (ret)
+ goto disable_dvfs;
+
+ return 0;
+
+disable_dvfs:
+ armada37xx_cpufreq_disable_dvfs(nb_pm_base);
+remove_opp:
+ /* clean-up the already added opp before leaving */
+ while (load_lvl-- > ARMADA_37XX_DVFS_LOAD_0) {
+ freq = base_frequency / dvfs->divider[load_lvl];
+ dev_pm_opp_remove(cpu_dev, freq);
+ }
+
+ kfree(armada37xx_cpufreq_state);
+
+ return ret;
+}
+/* late_initcall, to guarantee the driver is loaded after A37xx clock driver */
+late_initcall(armada37xx_cpufreq_driver_init);
+
+static const struct of_device_id __maybe_unused armada37xx_cpufreq_of_match[] = {
+ { .compatible = "marvell,armada-3700-nb-pm" },
+ { },
+};
+MODULE_DEVICE_TABLE(of, armada37xx_cpufreq_of_match);
+
+MODULE_AUTHOR("Gregory CLEMENT <gregory.clement@free-electrons.com>");
+MODULE_DESCRIPTION("Armada 37xx cpufreq driver");
+MODULE_LICENSE("GPL");
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-11 15:34:58 +0000