// SPDX-License-Identifier: GPL-2.0 /* * Tegra20 External Memory Controller driver * * Author: Dmitry Osipenko */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "../jedec_ddr.h" #include "../of_memory.h" #include "mc.h" #define EMC_INTSTATUS 0x000 #define EMC_INTMASK 0x004 #define EMC_DBG 0x008 #define EMC_ADR_CFG_0 0x010 #define EMC_TIMING_CONTROL 0x028 #define EMC_RC 0x02c #define EMC_RFC 0x030 #define EMC_RAS 0x034 #define EMC_RP 0x038 #define EMC_R2W 0x03c #define EMC_W2R 0x040 #define EMC_R2P 0x044 #define EMC_W2P 0x048 #define EMC_RD_RCD 0x04c #define EMC_WR_RCD 0x050 #define EMC_RRD 0x054 #define EMC_REXT 0x058 #define EMC_WDV 0x05c #define EMC_QUSE 0x060 #define EMC_QRST 0x064 #define EMC_QSAFE 0x068 #define EMC_RDV 0x06c #define EMC_REFRESH 0x070 #define EMC_BURST_REFRESH_NUM 0x074 #define EMC_PDEX2WR 0x078 #define EMC_PDEX2RD 0x07c #define EMC_PCHG2PDEN 0x080 #define EMC_ACT2PDEN 0x084 #define EMC_AR2PDEN 0x088 #define EMC_RW2PDEN 0x08c #define EMC_TXSR 0x090 #define EMC_TCKE 0x094 #define EMC_TFAW 0x098 #define EMC_TRPAB 0x09c #define EMC_TCLKSTABLE 0x0a0 #define EMC_TCLKSTOP 0x0a4 #define EMC_TREFBW 0x0a8 #define EMC_QUSE_EXTRA 0x0ac #define EMC_ODT_WRITE 0x0b0 #define EMC_ODT_READ 0x0b4 #define EMC_MRR 0x0ec #define EMC_FBIO_CFG5 0x104 #define EMC_FBIO_CFG6 0x114 #define EMC_STAT_CONTROL 0x160 #define EMC_STAT_LLMC_CONTROL 0x178 #define EMC_STAT_PWR_CLOCK_LIMIT 0x198 #define EMC_STAT_PWR_CLOCKS 0x19c #define EMC_STAT_PWR_COUNT 0x1a0 #define EMC_AUTO_CAL_INTERVAL 0x2a8 #define EMC_CFG_2 0x2b8 #define EMC_CFG_DIG_DLL 0x2bc #define EMC_DLL_XFORM_DQS 0x2c0 #define EMC_DLL_XFORM_QUSE 0x2c4 #define EMC_ZCAL_REF_CNT 0x2e0 #define EMC_ZCAL_WAIT_CNT 0x2e4 #define EMC_CFG_CLKTRIM_0 0x2d0 #define EMC_CFG_CLKTRIM_1 0x2d4 #define EMC_CFG_CLKTRIM_2 0x2d8 #define EMC_CLKCHANGE_REQ_ENABLE BIT(0) #define EMC_CLKCHANGE_PD_ENABLE BIT(1) #define EMC_CLKCHANGE_SR_ENABLE BIT(2) #define EMC_TIMING_UPDATE BIT(0) #define EMC_REFRESH_OVERFLOW_INT BIT(3) #define EMC_CLKCHANGE_COMPLETE_INT BIT(4) #define EMC_MRR_DIVLD_INT BIT(5) #define EMC_DBG_READ_MUX_ASSEMBLY BIT(0) #define EMC_DBG_WRITE_MUX_ACTIVE BIT(1) #define EMC_DBG_FORCE_UPDATE BIT(2) #define EMC_DBG_READ_DQM_CTRL BIT(9) #define EMC_DBG_CFG_PRIORITY BIT(24) #define EMC_FBIO_CFG5_DRAM_WIDTH_X16 BIT(4) #define EMC_FBIO_CFG5_DRAM_TYPE GENMASK(1, 0) #define EMC_MRR_DEV_SELECTN GENMASK(31, 30) #define EMC_MRR_MRR_MA GENMASK(23, 16) #define EMC_MRR_MRR_DATA GENMASK(15, 0) #define EMC_ADR_CFG_0_EMEM_NUMDEV GENMASK(25, 24) #define EMC_PWR_GATHER_CLEAR (1 << 8) #define EMC_PWR_GATHER_DISABLE (2 << 8) #define EMC_PWR_GATHER_ENABLE (3 << 8) enum emc_dram_type { DRAM_TYPE_RESERVED, DRAM_TYPE_DDR1, DRAM_TYPE_LPDDR2, DRAM_TYPE_DDR2, }; static const u16 emc_timing_registers[] = { EMC_RC, EMC_RFC, EMC_RAS, EMC_RP, EMC_R2W, EMC_W2R, EMC_R2P, EMC_W2P, EMC_RD_RCD, EMC_WR_RCD, EMC_RRD, EMC_REXT, EMC_WDV, EMC_QUSE, EMC_QRST, EMC_QSAFE, EMC_RDV, EMC_REFRESH, EMC_BURST_REFRESH_NUM, EMC_PDEX2WR, EMC_PDEX2RD, EMC_PCHG2PDEN, EMC_ACT2PDEN, EMC_AR2PDEN, EMC_RW2PDEN, EMC_TXSR, EMC_TCKE, EMC_TFAW, EMC_TRPAB, EMC_TCLKSTABLE, EMC_TCLKSTOP, EMC_TREFBW, EMC_QUSE_EXTRA, EMC_FBIO_CFG6, EMC_ODT_WRITE, EMC_ODT_READ, EMC_FBIO_CFG5, EMC_CFG_DIG_DLL, EMC_DLL_XFORM_DQS, EMC_DLL_XFORM_QUSE, EMC_ZCAL_REF_CNT, EMC_ZCAL_WAIT_CNT, EMC_AUTO_CAL_INTERVAL, EMC_CFG_CLKTRIM_0, EMC_CFG_CLKTRIM_1, EMC_CFG_CLKTRIM_2, }; struct emc_timing { unsigned long rate; u32 data[ARRAY_SIZE(emc_timing_registers)]; }; enum emc_rate_request_type { EMC_RATE_DEVFREQ, EMC_RATE_DEBUG, EMC_RATE_ICC, EMC_RATE_TYPE_MAX, }; struct emc_rate_request { unsigned long min_rate; unsigned long max_rate; }; struct tegra_emc { struct device *dev; struct tegra_mc *mc; struct icc_provider provider; struct notifier_block clk_nb; struct clk *clk; void __iomem *regs; unsigned int dram_bus_width; struct emc_timing *timings; unsigned int num_timings; struct { struct dentry *root; unsigned long min_rate; unsigned long max_rate; } debugfs; /* * There are multiple sources in the EMC driver which could request * a min/max clock rate, these rates are contained in this array. */ struct emc_rate_request requested_rate[EMC_RATE_TYPE_MAX]; /* protect shared rate-change code path */ struct mutex rate_lock; struct devfreq_simple_ondemand_data ondemand_data; /* memory chip identity information */ union lpddr2_basic_config4 basic_conf4; unsigned int manufacturer_id; unsigned int revision_id1; unsigned int revision_id2; bool mrr_error; }; static irqreturn_t tegra_emc_isr(int irq, void *data) { struct tegra_emc *emc = data; u32 intmask = EMC_REFRESH_OVERFLOW_INT; u32 status; status = readl_relaxed(emc->regs + EMC_INTSTATUS) & intmask; if (!status) return IRQ_NONE; /* notify about HW problem */ if (status & EMC_REFRESH_OVERFLOW_INT) dev_err_ratelimited(emc->dev, "refresh request overflow timeout\n"); /* clear interrupts */ writel_relaxed(status, emc->regs + EMC_INTSTATUS); return IRQ_HANDLED; } static struct emc_timing *tegra_emc_find_timing(struct tegra_emc *emc, unsigned long rate) { struct emc_timing *timing = NULL; unsigned int i; for (i = 0; i < emc->num_timings; i++) { if (emc->timings[i].rate >= rate) { timing = &emc->timings[i]; break; } } if (!timing) { dev_err(emc->dev, "no timing for rate %lu\n", rate); return NULL; } return timing; } static int emc_prepare_timing_change(struct tegra_emc *emc, unsigned long rate) { struct emc_timing *timing = tegra_emc_find_timing(emc, rate); unsigned int i; if (!timing) return -EINVAL; dev_dbg(emc->dev, "%s: using timing rate %lu for requested rate %lu\n", __func__, timing->rate, rate); /* program shadow registers */ for (i = 0; i < ARRAY_SIZE(timing->data); i++) writel_relaxed(timing->data[i], emc->regs + emc_timing_registers[i]); /* wait until programming has settled */ readl_relaxed(emc->regs + emc_timing_registers[i - 1]); return 0; } static int emc_complete_timing_change(struct tegra_emc *emc, bool flush) { int err; u32 v; dev_dbg(emc->dev, "%s: flush %d\n", __func__, flush); if (flush) { /* manually initiate memory timing update */ writel_relaxed(EMC_TIMING_UPDATE, emc->regs + EMC_TIMING_CONTROL); return 0; } err = readl_relaxed_poll_timeout_atomic(emc->regs + EMC_INTSTATUS, v, v & EMC_CLKCHANGE_COMPLETE_INT, 1, 100); if (err) { dev_err(emc->dev, "emc-car handshake timeout: %d\n", err); return err; } return 0; } static int tegra_emc_clk_change_notify(struct notifier_block *nb, unsigned long msg, void *data) { struct tegra_emc *emc = container_of(nb, struct tegra_emc, clk_nb); struct clk_notifier_data *cnd = data; int err; switch (msg) { case PRE_RATE_CHANGE: err = emc_prepare_timing_change(emc, cnd->new_rate); break; case ABORT_RATE_CHANGE: err = emc_prepare_timing_change(emc, cnd->old_rate); if (err) break; err = emc_complete_timing_change(emc, true); break; case POST_RATE_CHANGE: err = emc_complete_timing_change(emc, false); break; default: return NOTIFY_DONE; } return notifier_from_errno(err); } static int load_one_timing_from_dt(struct tegra_emc *emc, struct emc_timing *timing, struct device_node *node) { u32 rate; int err; if (!of_device_is_compatible(node, "nvidia,tegra20-emc-table")) { dev_err(emc->dev, "incompatible DT node: %pOF\n", node); return -EINVAL; } err = of_property_read_u32(node, "clock-frequency", &rate); if (err) { dev_err(emc->dev, "timing %pOF: failed to read rate: %d\n", node, err); return err; } err = of_property_read_u32_array(node, "nvidia,emc-registers", timing->data, ARRAY_SIZE(emc_timing_registers)); if (err) { dev_err(emc->dev, "timing %pOF: failed to read emc timing data: %d\n", node, err); return err; } /* * The EMC clock rate is twice the bus rate, and the bus rate is * measured in kHz. */ timing->rate = rate * 2 * 1000; dev_dbg(emc->dev, "%s: %pOF: EMC rate %lu\n", __func__, node, timing->rate); return 0; } static int cmp_timings(const void *_a, const void *_b) { const struct emc_timing *a = _a; const struct emc_timing *b = _b; if (a->rate < b->rate) return -1; if (a->rate > b->rate) return 1; return 0; } static int tegra_emc_load_timings_from_dt(struct tegra_emc *emc, struct device_node *node) { struct device_node *child; struct emc_timing *timing; int child_count; int err; child_count = of_get_child_count(node); if (!child_count) { dev_err(emc->dev, "no memory timings in DT node: %pOF\n", node); return -EINVAL; } emc->timings = devm_kcalloc(emc->dev, child_count, sizeof(*timing), GFP_KERNEL); if (!emc->timings) return -ENOMEM; timing = emc->timings; for_each_child_of_node(node, child) { if (of_node_name_eq(child, "lpddr2")) continue; err = load_one_timing_from_dt(emc, timing++, child); if (err) { of_node_put(child); return err; } emc->num_timings++; } sort(emc->timings, emc->num_timings, sizeof(*timing), cmp_timings, NULL); dev_info_once(emc->dev, "got %u timings for RAM code %u (min %luMHz max %luMHz)\n", emc->num_timings, tegra_read_ram_code(), emc->timings[0].rate / 1000000, emc->timings[emc->num_timings - 1].rate / 1000000); return 0; } static struct device_node * tegra_emc_find_node_by_ram_code(struct tegra_emc *emc) { struct device *dev = emc->dev; struct device_node *np; u32 value, ram_code; int err; if (emc->mrr_error) { dev_warn(dev, "memory timings skipped due to MRR error\n"); return NULL; } if (of_get_child_count(dev->of_node) == 0) { dev_info_once(dev, "device-tree doesn't have memory timings\n"); return NULL; } if (!of_property_read_bool(dev->of_node, "nvidia,use-ram-code")) return of_node_get(dev->of_node); ram_code = tegra_read_ram_code(); for (np = of_find_node_by_name(dev->of_node, "emc-tables"); np; np = of_find_node_by_name(np, "emc-tables")) { err = of_property_read_u32(np, "nvidia,ram-code", &value); if (err || value != ram_code) { struct device_node *lpddr2_np; bool cfg_mismatches = false; lpddr2_np = of_find_node_by_name(np, "lpddr2"); if (lpddr2_np) { const struct lpddr2_info *info; info = of_lpddr2_get_info(lpddr2_np, dev); if (info) { if (info->manufacturer_id >= 0 && info->manufacturer_id != emc->manufacturer_id) cfg_mismatches = true; if (info->revision_id1 >= 0 && info->revision_id1 != emc->revision_id1) cfg_mismatches = true; if (info->revision_id2 >= 0 && info->revision_id2 != emc->revision_id2) cfg_mismatches = true; if (info->density != emc->basic_conf4.density) cfg_mismatches = true; if (info->io_width != emc->basic_conf4.io_width) cfg_mismatches = true; if (info->arch_type != emc->basic_conf4.arch_type) cfg_mismatches = true; } else { dev_err(dev, "failed to parse %pOF\n", lpddr2_np); cfg_mismatches = true; } of_node_put(lpddr2_np); } else { cfg_mismatches = true; } if (cfg_mismatches) { of_node_put(np); continue; } } return np; } dev_err(dev, "no memory timings for RAM code %u found in device tree\n", ram_code); return NULL; } static int emc_read_lpddr_mode_register(struct tegra_emc *emc, unsigned int emem_dev, unsigned int register_addr, unsigned int *register_data) { u32 memory_dev = emem_dev ? 1 : 2; u32 val, mr_mask = 0xff; int err; /* clear data-valid interrupt status */ writel_relaxed(EMC_MRR_DIVLD_INT, emc->regs + EMC_INTSTATUS); /* issue mode register read request */ val = FIELD_PREP(EMC_MRR_DEV_SELECTN, memory_dev); val |= FIELD_PREP(EMC_MRR_MRR_MA, register_addr); writel_relaxed(val, emc->regs + EMC_MRR); /* wait for the LPDDR2 data-valid interrupt */ err = readl_relaxed_poll_timeout_atomic(emc->regs + EMC_INTSTATUS, val, val & EMC_MRR_DIVLD_INT, 1, 100); if (err) { dev_err(emc->dev, "mode register %u read failed: %d\n", register_addr, err); emc->mrr_error = true; return err; } /* read out mode register data */ val = readl_relaxed(emc->regs + EMC_MRR); *register_data = FIELD_GET(EMC_MRR_MRR_DATA, val) & mr_mask; return 0; } static void emc_read_lpddr_sdram_info(struct tegra_emc *emc, unsigned int emem_dev, bool print_out) { /* these registers are standard for all LPDDR JEDEC memory chips */ emc_read_lpddr_mode_register(emc, emem_dev, 5, &emc->manufacturer_id); emc_read_lpddr_mode_register(emc, emem_dev, 6, &emc->revision_id1); emc_read_lpddr_mode_register(emc, emem_dev, 7, &emc->revision_id2); emc_read_lpddr_mode_register(emc, emem_dev, 8, &emc->basic_conf4.value); if (!print_out) return; dev_info(emc->dev, "SDRAM[dev%u]: manufacturer: 0x%x (%s) rev1: 0x%x rev2: 0x%x prefetch: S%u density: %uMbit iowidth: %ubit\n", emem_dev, emc->manufacturer_id, lpddr2_jedec_manufacturer(emc->manufacturer_id), emc->revision_id1, emc->revision_id2, 4 >> emc->basic_conf4.arch_type, 64 << emc->basic_conf4.density, 32 >> emc->basic_conf4.io_width); } static int emc_setup_hw(struct tegra_emc *emc) { u32 emc_cfg, emc_dbg, emc_fbio, emc_adr_cfg; u32 intmask = EMC_REFRESH_OVERFLOW_INT; static bool print_sdram_info_once; enum emc_dram_type dram_type; const char *dram_type_str; unsigned int emem_numdev; emc_cfg = readl_relaxed(emc->regs + EMC_CFG_2); /* * Depending on a memory type, DRAM should enter either self-refresh * or power-down state on EMC clock change. */ if (!(emc_cfg & EMC_CLKCHANGE_PD_ENABLE) && !(emc_cfg & EMC_CLKCHANGE_SR_ENABLE)) { dev_err(emc->dev, "bootloader didn't specify DRAM auto-suspend mode\n"); return -EINVAL; } /* enable EMC and CAR to handshake on PLL divider/source changes */ emc_cfg |= EMC_CLKCHANGE_REQ_ENABLE; writel_relaxed(emc_cfg, emc->regs + EMC_CFG_2); /* initialize interrupt */ writel_relaxed(intmask, emc->regs + EMC_INTMASK); writel_relaxed(intmask, emc->regs + EMC_INTSTATUS); /* ensure that unwanted debug features are disabled */ emc_dbg = readl_relaxed(emc->regs + EMC_DBG); emc_dbg |= EMC_DBG_CFG_PRIORITY; emc_dbg &= ~EMC_DBG_READ_MUX_ASSEMBLY; emc_dbg &= ~EMC_DBG_WRITE_MUX_ACTIVE; emc_dbg &= ~EMC_DBG_FORCE_UPDATE; writel_relaxed(emc_dbg, emc->regs + EMC_DBG); emc_fbio = readl_relaxed(emc->regs + EMC_FBIO_CFG5); if (emc_fbio & EMC_FBIO_CFG5_DRAM_WIDTH_X16) emc->dram_bus_width = 16; else emc->dram_bus_width = 32; dram_type = FIELD_GET(EMC_FBIO_CFG5_DRAM_TYPE, emc_fbio); switch (dram_type) { case DRAM_TYPE_RESERVED: dram_type_str = "INVALID"; break; case DRAM_TYPE_DDR1: dram_type_str = "DDR1"; break; case DRAM_TYPE_LPDDR2: dram_type_str = "LPDDR2"; break; case DRAM_TYPE_DDR2: dram_type_str = "DDR2"; break; } emc_adr_cfg = readl_relaxed(emc->regs + EMC_ADR_CFG_0); emem_numdev = FIELD_GET(EMC_ADR_CFG_0_EMEM_NUMDEV, emc_adr_cfg) + 1; dev_info_once(emc->dev, "%ubit DRAM bus, %u %s %s attached\n", emc->dram_bus_width, emem_numdev, dram_type_str, emem_numdev == 2 ? "devices" : "device"); if (dram_type == DRAM_TYPE_LPDDR2) { while (emem_numdev--) emc_read_lpddr_sdram_info(emc, emem_numdev, !print_sdram_info_once); print_sdram_info_once = true; } return 0; } static long emc_round_rate(unsigned long rate, unsigned long min_rate, unsigned long max_rate, void *arg) { struct emc_timing *timing = NULL; struct tegra_emc *emc = arg; unsigned int i; if (!emc->num_timings) return clk_get_rate(emc->clk); min_rate = min(min_rate, emc->timings[emc->num_timings - 1].rate); for (i = 0; i < emc->num_timings; i++) { if (emc->timings[i].rate < rate && i != emc->num_timings - 1) continue; if (emc->timings[i].rate > max_rate) { i = max(i, 1u) - 1; if (emc->timings[i].rate < min_rate) break; } if (emc->timings[i].rate < min_rate) continue; timing = &emc->timings[i]; break; } if (!timing) { dev_err(emc->dev, "no timing for rate %lu min %lu max %lu\n", rate, min_rate, max_rate); return -EINVAL; } return timing->rate; } static void tegra_emc_rate_requests_init(struct tegra_emc *emc) { unsigned int i; for (i = 0; i < EMC_RATE_TYPE_MAX; i++) { emc->requested_rate[i].min_rate = 0; emc->requested_rate[i].max_rate = ULONG_MAX; } } static int emc_request_rate(struct tegra_emc *emc, unsigned long new_min_rate, unsigned long new_max_rate, enum emc_rate_request_type type) { struct emc_rate_request *req = emc->requested_rate; unsigned long min_rate = 0, max_rate = ULONG_MAX; unsigned int i; int err; /* select minimum and maximum rates among the requested rates */ for (i = 0; i < EMC_RATE_TYPE_MAX; i++, req++) { if (i == type) { min_rate = max(new_min_rate, min_rate); max_rate = min(new_max_rate, max_rate); } else { min_rate = max(req->min_rate, min_rate); max_rate = min(req->max_rate, max_rate); } } if (min_rate > max_rate) { dev_err_ratelimited(emc->dev, "%s: type %u: out of range: %lu %lu\n", __func__, type, min_rate, max_rate); return -ERANGE; } /* * EMC rate-changes should go via OPP API because it manages voltage * changes. */ err = dev_pm_opp_set_rate(emc->dev, min_rate); if (err) return err; emc->requested_rate[type].min_rate = new_min_rate; emc->requested_rate[type].max_rate = new_max_rate; return 0; } static int emc_set_min_rate(struct tegra_emc *emc, unsigned long rate, enum emc_rate_request_type type) { struct emc_rate_request *req = &emc->requested_rate[type]; int ret; mutex_lock(&emc->rate_lock); ret = emc_request_rate(emc, rate, req->max_rate, type); mutex_unlock(&emc->rate_lock); return ret; } static int emc_set_max_rate(struct tegra_emc *emc, unsigned long rate, enum emc_rate_request_type type) { struct emc_rate_request *req = &emc->requested_rate[type]; int ret; mutex_lock(&emc->rate_lock); ret = emc_request_rate(emc, req->min_rate, rate, type); mutex_unlock(&emc->rate_lock); return ret; } /* * debugfs interface * * The memory controller driver exposes some files in debugfs that can be used * to control the EMC frequency. The top-level directory can be found here: * * /sys/kernel/debug/emc * * It contains the following files: * * - available_rates: This file contains a list of valid, space-separated * EMC frequencies. * * - min_rate: Writing a value to this file sets the given frequency as the * floor of the permitted range. If this is higher than the currently * configured EMC frequency, this will cause the frequency to be * increased so that it stays within the valid range. * * - max_rate: Similarily to the min_rate file, writing a value to this file * sets the given frequency as the ceiling of the permitted range. If * the value is lower than the currently configured EMC frequency, this * will cause the frequency to be decreased so that it stays within the * valid range. */ static bool tegra_emc_validate_rate(struct tegra_emc *emc, unsigned long rate) { unsigned int i; for (i = 0; i < emc->num_timings; i++) if (rate == emc->timings[i].rate) return true; return false; } static int tegra_emc_debug_available_rates_show(struct seq_file *s, void *data) { struct tegra_emc *emc = s->private; const char *prefix = ""; unsigned int i; for (i = 0; i < emc->num_timings; i++) { seq_printf(s, "%s%lu", prefix, emc->timings[i].rate); prefix = " "; } seq_puts(s, "\n"); return 0; } DEFINE_SHOW_ATTRIBUTE(tegra_emc_debug_available_rates); static int tegra_emc_debug_min_rate_get(void *data, u64 *rate) { struct tegra_emc *emc = data; *rate = emc->debugfs.min_rate; return 0; } static int tegra_emc_debug_min_rate_set(void *data, u64 rate) { struct tegra_emc *emc = data; int err; if (!tegra_emc_validate_rate(emc, rate)) return -EINVAL; err = emc_set_min_rate(emc, rate, EMC_RATE_DEBUG); if (err < 0) return err; emc->debugfs.min_rate = rate; return 0; } DEFINE_SIMPLE_ATTRIBUTE(tegra_emc_debug_min_rate_fops, tegra_emc_debug_min_rate_get, tegra_emc_debug_min_rate_set, "%llu\n"); static int tegra_emc_debug_max_rate_get(void *data, u64 *rate) { struct tegra_emc *emc = data; *rate = emc->debugfs.max_rate; return 0; } static int tegra_emc_debug_max_rate_set(void *data, u64 rate) { struct tegra_emc *emc = data; int err; if (!tegra_emc_validate_rate(emc, rate)) return -EINVAL; err = emc_set_max_rate(emc, rate, EMC_RATE_DEBUG); if (err < 0) return err; emc->debugfs.max_rate = rate; return 0; } DEFINE_SIMPLE_ATTRIBUTE(tegra_emc_debug_max_rate_fops, tegra_emc_debug_max_rate_get, tegra_emc_debug_max_rate_set, "%llu\n"); static void tegra_emc_debugfs_init(struct tegra_emc *emc) { struct device *dev = emc->dev; unsigned int i; int err; emc->debugfs.min_rate = ULONG_MAX; emc->debugfs.max_rate = 0; for (i = 0; i < emc->num_timings; i++) { if (emc->timings[i].rate < emc->debugfs.min_rate) emc->debugfs.min_rate = emc->timings[i].rate; if (emc->timings[i].rate > emc->debugfs.max_rate) emc->debugfs.max_rate = emc->timings[i].rate; } if (!emc->num_timings) { emc->debugfs.min_rate = clk_get_rate(emc->clk); emc->debugfs.max_rate = emc->debugfs.min_rate; } err = clk_set_rate_range(emc->clk, emc->debugfs.min_rate, emc->debugfs.max_rate); if (err < 0) { dev_err(dev, "failed to set rate range [%lu-%lu] for %pC\n", emc->debugfs.min_rate, emc->debugfs.max_rate, emc->clk); } emc->debugfs.root = debugfs_create_dir("emc", NULL); debugfs_create_file("available_rates", 0444, emc->debugfs.root, emc, &tegra_emc_debug_available_rates_fops); debugfs_create_file("min_rate", 0644, emc->debugfs.root, emc, &tegra_emc_debug_min_rate_fops); debugfs_create_file("max_rate", 0644, emc->debugfs.root, emc, &tegra_emc_debug_max_rate_fops); } static inline struct tegra_emc * to_tegra_emc_provider(struct icc_provider *provider) { return container_of(provider, struct tegra_emc, provider); } static struct icc_node_data * emc_of_icc_xlate_extended(struct of_phandle_args *spec, void *data) { struct icc_provider *provider = data; struct icc_node_data *ndata; struct icc_node *node; /* External Memory is the only possible ICC route */ list_for_each_entry(node, &provider->nodes, node_list) { if (node->id != TEGRA_ICC_EMEM) continue; ndata = kzalloc(sizeof(*ndata), GFP_KERNEL); if (!ndata) return ERR_PTR(-ENOMEM); /* * SRC and DST nodes should have matching TAG in order to have * it set by default for a requested path. */ ndata->tag = TEGRA_MC_ICC_TAG_ISO; ndata->node = node; return ndata; } return ERR_PTR(-EPROBE_DEFER); } static int emc_icc_set(struct icc_node *src, struct icc_node *dst) { struct tegra_emc *emc = to_tegra_emc_provider(dst->provider); unsigned long long peak_bw = icc_units_to_bps(dst->peak_bw); unsigned long long avg_bw = icc_units_to_bps(dst->avg_bw); unsigned long long rate = max(avg_bw, peak_bw); unsigned int dram_data_bus_width_bytes; int err; /* * Tegra20 EMC runs on x2 clock rate of SDRAM bus because DDR data * is sampled on both clock edges. This means that EMC clock rate * equals to the peak data-rate. */ dram_data_bus_width_bytes = emc->dram_bus_width / 8; do_div(rate, dram_data_bus_width_bytes); rate = min_t(u64, rate, U32_MAX); err = emc_set_min_rate(emc, rate, EMC_RATE_ICC); if (err) return err; return 0; } static int tegra_emc_interconnect_init(struct tegra_emc *emc) { const struct tegra_mc_soc *soc; struct icc_node *node; int err; emc->mc = devm_tegra_memory_controller_get(emc->dev); if (IS_ERR(emc->mc)) return PTR_ERR(emc->mc); soc = emc->mc->soc; emc->provider.dev = emc->dev; emc->provider.set = emc_icc_set; emc->provider.data = &emc->provider; emc->provider.aggregate = soc->icc_ops->aggregate; emc->provider.xlate_extended = emc_of_icc_xlate_extended; icc_provider_init(&emc->provider); /* create External Memory Controller node */ node = icc_node_create(TEGRA_ICC_EMC); if (IS_ERR(node)) { err = PTR_ERR(node); goto err_msg; } node->name = "External Memory Controller"; icc_node_add(node, &emc->provider); /* link External Memory Controller to External Memory (DRAM) */ err = icc_link_create(node, TEGRA_ICC_EMEM); if (err) goto remove_nodes; /* create External Memory node */ node = icc_node_create(TEGRA_ICC_EMEM); if (IS_ERR(node)) { err = PTR_ERR(node); goto remove_nodes; } node->name = "External Memory (DRAM)"; icc_node_add(node, &emc->provider); err = icc_provider_register(&emc->provider); if (err) goto remove_nodes; return 0; remove_nodes: icc_nodes_remove(&emc->provider); err_msg: dev_err(emc->dev, "failed to initialize ICC: %d\n", err); return err; } static void devm_tegra_emc_unset_callback(void *data) { tegra20_clk_set_emc_round_callback(NULL, NULL); } static void devm_tegra_emc_unreg_clk_notifier(void *data) { struct tegra_emc *emc = data; clk_notifier_unregister(emc->clk, &emc->clk_nb); } static int tegra_emc_init_clk(struct tegra_emc *emc) { int err; tegra20_clk_set_emc_round_callback(emc_round_rate, emc); err = devm_add_action_or_reset(emc->dev, devm_tegra_emc_unset_callback, NULL); if (err) return err; emc->clk = devm_clk_get(emc->dev, NULL); if (IS_ERR(emc->clk)) { dev_err(emc->dev, "failed to get EMC clock: %pe\n", emc->clk); return PTR_ERR(emc->clk); } err = clk_notifier_register(emc->clk, &emc->clk_nb); if (err) { dev_err(emc->dev, "failed to register clk notifier: %d\n", err); return err; } err = devm_add_action_or_reset(emc->dev, devm_tegra_emc_unreg_clk_notifier, emc); if (err) return err; return 0; } static int tegra_emc_devfreq_target(struct device *dev, unsigned long *freq, u32 flags) { struct tegra_emc *emc = dev_get_drvdata(dev); struct dev_pm_opp *opp; unsigned long rate; opp = devfreq_recommended_opp(dev, freq, flags); if (IS_ERR(opp)) { dev_err(dev, "failed to find opp for %lu Hz\n", *freq); return PTR_ERR(opp); } rate = dev_pm_opp_get_freq(opp); dev_pm_opp_put(opp); return emc_set_min_rate(emc, rate, EMC_RATE_DEVFREQ); } static int tegra_emc_devfreq_get_dev_status(struct device *dev, struct devfreq_dev_status *stat) { struct tegra_emc *emc = dev_get_drvdata(dev); /* freeze counters */ writel_relaxed(EMC_PWR_GATHER_DISABLE, emc->regs + EMC_STAT_CONTROL); /* * busy_time: number of clocks EMC request was accepted * total_time: number of clocks PWR_GATHER control was set to ENABLE */ stat->busy_time = readl_relaxed(emc->regs + EMC_STAT_PWR_COUNT); stat->total_time = readl_relaxed(emc->regs + EMC_STAT_PWR_CLOCKS); stat->current_frequency = clk_get_rate(emc->clk); /* clear counters and restart */ writel_relaxed(EMC_PWR_GATHER_CLEAR, emc->regs + EMC_STAT_CONTROL); writel_relaxed(EMC_PWR_GATHER_ENABLE, emc->regs + EMC_STAT_CONTROL); return 0; } static struct devfreq_dev_profile tegra_emc_devfreq_profile = { .polling_ms = 30, .target = tegra_emc_devfreq_target, .get_dev_status = tegra_emc_devfreq_get_dev_status, }; static int tegra_emc_devfreq_init(struct tegra_emc *emc) { struct devfreq *devfreq; /* * PWR_COUNT is 1/2 of PWR_CLOCKS at max, and thus, the up-threshold * should be less than 50. Secondly, multiple active memory clients * may cause over 20% of lost clock cycles due to stalls caused by * competing memory accesses. This means that threshold should be * set to a less than 30 in order to have a properly working governor. */ emc->ondemand_data.upthreshold = 20; /* * Reset statistic gathers state, select global bandwidth for the * statistics collection mode and set clocks counter saturation * limit to maximum. */ writel_relaxed(0x00000000, emc->regs + EMC_STAT_CONTROL); writel_relaxed(0x00000000, emc->regs + EMC_STAT_LLMC_CONTROL); writel_relaxed(0xffffffff, emc->regs + EMC_STAT_PWR_CLOCK_LIMIT); devfreq = devm_devfreq_add_device(emc->dev, &tegra_emc_devfreq_profile, DEVFREQ_GOV_SIMPLE_ONDEMAND, &emc->ondemand_data); if (IS_ERR(devfreq)) { dev_err(emc->dev, "failed to initialize devfreq: %pe", devfreq); return PTR_ERR(devfreq); } return 0; } static int tegra_emc_probe(struct platform_device *pdev) { struct tegra_core_opp_params opp_params = {}; struct device_node *np; struct tegra_emc *emc; int irq, err; irq = platform_get_irq(pdev, 0); if (irq < 0) { dev_err(&pdev->dev, "please update your device tree\n"); return irq; } emc = devm_kzalloc(&pdev->dev, sizeof(*emc), GFP_KERNEL); if (!emc) return -ENOMEM; mutex_init(&emc->rate_lock); emc->clk_nb.notifier_call = tegra_emc_clk_change_notify; emc->dev = &pdev->dev; emc->regs = devm_platform_ioremap_resource(pdev, 0); if (IS_ERR(emc->regs)) return PTR_ERR(emc->regs); err = emc_setup_hw(emc); if (err) return err; np = tegra_emc_find_node_by_ram_code(emc); if (np) { err = tegra_emc_load_timings_from_dt(emc, np); of_node_put(np); if (err) return err; } err = devm_request_irq(&pdev->dev, irq, tegra_emc_isr, 0, dev_name(&pdev->dev), emc); if (err) { dev_err(&pdev->dev, "failed to request IRQ: %d\n", err); return err; } err = tegra_emc_init_clk(emc); if (err) return err; opp_params.init_state = true; err = devm_tegra_core_dev_init_opp_table(&pdev->dev, &opp_params); if (err) return err; platform_set_drvdata(pdev, emc); tegra_emc_rate_requests_init(emc); tegra_emc_debugfs_init(emc); tegra_emc_interconnect_init(emc); tegra_emc_devfreq_init(emc); /* * Don't allow the kernel module to be unloaded. Unloading adds some * extra complexity which doesn't really worth the effort in a case of * this driver. */ try_module_get(THIS_MODULE); return 0; } static const struct of_device_id tegra_emc_of_match[] = { { .compatible = "nvidia,tegra20-emc", }, {}, }; MODULE_DEVICE_TABLE(of, tegra_emc_of_match); static struct platform_driver tegra_emc_driver = { .probe = tegra_emc_probe, .driver = { .name = "tegra20-emc", .of_match_table = tegra_emc_of_match, .suppress_bind_attrs = true, .sync_state = icc_sync_state, }, }; module_platform_driver(tegra_emc_driver); MODULE_AUTHOR("Dmitry Osipenko "); MODULE_DESCRIPTION("NVIDIA Tegra20 EMC driver"); MODULE_SOFTDEP("pre: governor_simpleondemand"); MODULE_LICENSE("GPL v2");