diff options
| -rw-r--r-- | drivers/memory/tegra/Kconfig | 10 | ||||
| -rw-r--r-- | drivers/memory/tegra/Makefile | 1 | ||||
| -rw-r--r-- | drivers/memory/tegra/tegra20-emc.c | 591 |
3 files changed, 602 insertions, 0 deletions
diff --git a/drivers/memory/tegra/Kconfig b/drivers/memory/tegra/Kconfig index 6d74e499e18d..34e0b70f5c5f 100644 --- a/drivers/memory/tegra/Kconfig +++ b/drivers/memory/tegra/Kconfig @@ -6,6 +6,16 @@ config TEGRA_MC This driver supports the Memory Controller (MC) hardware found on NVIDIA Tegra SoCs. +config TEGRA20_EMC + bool "NVIDIA Tegra20 External Memory Controller driver" + default y + depends on ARCH_TEGRA_2x_SOC + help + This driver is for the External Memory Controller (EMC) found on + Tegra20 chips. The EMC controls the external DRAM on the board. + This driver is required to change memory timings / clock rate for + external memory. + config TEGRA124_EMC bool "NVIDIA Tegra124 External Memory Controller driver" default y diff --git a/drivers/memory/tegra/Makefile b/drivers/memory/tegra/Makefile index 94ab16ba075b..3971a6b7c487 100644 --- a/drivers/memory/tegra/Makefile +++ b/drivers/memory/tegra/Makefile @@ -10,5 +10,6 @@ tegra-mc-$(CONFIG_ARCH_TEGRA_210_SOC) += tegra210.o obj-$(CONFIG_TEGRA_MC) += tegra-mc.o +obj-$(CONFIG_TEGRA20_EMC) += tegra20-emc.o obj-$(CONFIG_TEGRA124_EMC) += tegra124-emc.o obj-$(CONFIG_ARCH_TEGRA_186_SOC) += tegra186.o diff --git a/drivers/memory/tegra/tegra20-emc.c b/drivers/memory/tegra/tegra20-emc.c new file mode 100644 index 000000000000..9ee5bef49e47 --- /dev/null +++ b/drivers/memory/tegra/tegra20-emc.c @@ -0,0 +1,591 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Tegra20 External Memory Controller driver + * + * Author: Dmitry Osipenko <digetx@gmail.com> + */ + +#include <linux/clk.h> +#include <linux/completion.h> +#include <linux/err.h> +#include <linux/interrupt.h> +#include <linux/iopoll.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/of.h> +#include <linux/platform_device.h> +#include <linux/sort.h> +#include <linux/types.h> + +#include <soc/tegra/fuse.h> + +#define EMC_INTSTATUS 0x000 +#define EMC_INTMASK 0x004 +#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_FBIO_CFG5 0x104 +#define EMC_FBIO_CFG6 0x114 +#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) + +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)]; +}; + +struct tegra_emc { + struct device *dev; + struct completion clk_handshake_complete; + struct notifier_block clk_nb; + struct clk *backup_clk; + struct clk *emc_mux; + struct clk *pll_m; + struct clk *clk; + void __iomem *regs; + + struct emc_timing *timings; + unsigned int num_timings; +}; + +static irqreturn_t tegra_emc_isr(int irq, void *data) +{ + struct tegra_emc *emc = data; + u32 intmask = EMC_REFRESH_OVERFLOW_INT | EMC_CLKCHANGE_COMPLETE_INT; + u32 status; + + status = readl_relaxed(emc->regs + EMC_INTSTATUS) & intmask; + if (!status) + return IRQ_NONE; + + /* notify about EMC-CAR handshake completion */ + if (status & EMC_CLKCHANGE_COMPLETE_INT) + complete(&emc->clk_handshake_complete); + + /* 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]); + + reinit_completion(&emc->clk_handshake_complete); + + return 0; +} + +static int emc_complete_timing_change(struct tegra_emc *emc, bool flush) +{ + long timeout; + + 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; + } + + timeout = wait_for_completion_timeout(&emc->clk_handshake_complete, + usecs_to_jiffies(100)); + if (timeout == 0) { + dev_err(emc->dev, "EMC-CAR handshake failed\n"); + return -EIO; + } else if (timeout < 0) { + dev_err(emc->dev, "failed to wait for EMC-CAR handshake: %ld\n", + timeout); + return timeout; + } + + 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; + + emc->num_timings = child_count; + timing = emc->timings; + + for_each_child_of_node(node, child) { + err = load_one_timing_from_dt(emc, timing++, child); + if (err) { + of_node_put(child); + return err; + } + } + + sort(emc->timings, emc->num_timings, sizeof(*timing), cmp_timings, + NULL); + + return 0; +} + +static struct device_node * +tegra_emc_find_node_by_ram_code(struct device *dev) +{ + struct device_node *np; + u32 value, ram_code; + int err; + + 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) { + 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_setup_hw(struct tegra_emc *emc) +{ + u32 intmask = EMC_REFRESH_OVERFLOW_INT | EMC_CLKCHANGE_COMPLETE_INT; + u32 emc_cfg; + + 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); + + return 0; +} + +static int emc_init(struct tegra_emc *emc, unsigned long rate) +{ + int err; + + err = clk_set_parent(emc->emc_mux, emc->backup_clk); + if (err) { + dev_err(emc->dev, + "failed to reparent to backup source: %d\n", err); + return err; + } + + err = clk_set_rate(emc->pll_m, rate); + if (err) { + dev_err(emc->dev, + "failed to change pll_m rate: %d\n", err); + return err; + } + + err = clk_set_parent(emc->emc_mux, emc->pll_m); + if (err) { + dev_err(emc->dev, + "failed to reparent to pll_m: %d\n", err); + return err; + } + + err = clk_set_rate(emc->clk, rate); + if (err) { + dev_err(emc->dev, + "failed to change emc rate: %d\n", err); + return err; + } + + return 0; +} + +static int tegra_emc_probe(struct platform_device *pdev) +{ + struct device_node *np; + struct tegra_emc *emc; + struct resource *res; + int irq, err; + + /* driver has nothing to do in a case of memory timing absence */ + if (of_get_child_count(pdev->dev.of_node) == 0) { + dev_info(&pdev->dev, + "EMC device tree node doesn't have memory timings\n"); + return 0; + } + + irq = platform_get_irq(pdev, 0); + if (irq < 0) { + dev_err(&pdev->dev, "interrupt not specified\n"); + dev_err(&pdev->dev, "please update your device tree\n"); + return irq; + } + + np = tegra_emc_find_node_by_ram_code(&pdev->dev); + if (!np) + return -EINVAL; + + emc = devm_kzalloc(&pdev->dev, sizeof(*emc), GFP_KERNEL); + if (!emc) { + of_node_put(np); + return -ENOMEM; + } + + init_completion(&emc->clk_handshake_complete); + emc->clk_nb.notifier_call = tegra_emc_clk_change_notify; + emc->dev = &pdev->dev; + + err = tegra_emc_load_timings_from_dt(emc, np); + of_node_put(np); + if (err) + return err; + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + emc->regs = devm_ioremap_resource(&pdev->dev, res); + if (IS_ERR(emc->regs)) + return PTR_ERR(emc->regs); + + err = emc_setup_hw(emc); + 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#%u: %d\n", irq, err); + return err; + } + + emc->clk = devm_clk_get(&pdev->dev, "emc"); + if (IS_ERR(emc->clk)) { + err = PTR_ERR(emc->clk); + dev_err(&pdev->dev, "failed to get emc clock: %d\n", err); + return err; + } + + emc->pll_m = clk_get_sys(NULL, "pll_m"); + if (IS_ERR(emc->pll_m)) { + err = PTR_ERR(emc->pll_m); + dev_err(&pdev->dev, "failed to get pll_m clock: %d\n", err); + return err; + } + + emc->backup_clk = clk_get_sys(NULL, "pll_p"); + if (IS_ERR(emc->backup_clk)) { + err = PTR_ERR(emc->backup_clk); + dev_err(&pdev->dev, "failed to get pll_p clock: %d\n", err); + goto put_pll_m; + } + + emc->emc_mux = clk_get_parent(emc->clk); + if (IS_ERR(emc->emc_mux)) { + err = PTR_ERR(emc->emc_mux); + dev_err(&pdev->dev, "failed to get emc_mux clock: %d\n", err); + goto put_backup; + } + + err = clk_notifier_register(emc->clk, &emc->clk_nb); + if (err) { + dev_err(&pdev->dev, "failed to register clk notifier: %d\n", + err); + goto put_backup; + } + + /* set DRAM clock rate to maximum */ + err = emc_init(emc, emc->timings[emc->num_timings - 1].rate); + if (err) { + dev_err(&pdev->dev, "failed to initialize EMC clock rate: %d\n", + err); + goto unreg_notifier; + } + + return 0; + +unreg_notifier: + clk_notifier_unregister(emc->clk, &emc->clk_nb); +put_backup: + clk_put(emc->backup_clk); +put_pll_m: + clk_put(emc->pll_m); + + return err; +} + +static const struct of_device_id tegra_emc_of_match[] = { + { .compatible = "nvidia,tegra20-emc", }, + {}, +}; + +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, + }, +}; + +static int __init tegra_emc_init(void) +{ + return platform_driver_register(&tegra_emc_driver); +} +subsys_initcall(tegra_emc_init); |