/* * DDR PHY Front End (DPFE) driver for Broadcom set top box SoCs * * Copyright (c) 2017 Broadcom * * Released under the GPLv2 only. * SPDX-License-Identifier: GPL-2.0 */ /* * This driver provides access to the DPFE interface of Broadcom STB SoCs. * The firmware running on the DCPU inside the DDR PHY can provide current * information about the system's RAM, for instance the DRAM refresh rate. * This can be used as an indirect indicator for the DRAM's temperature. * Slower refresh rate means cooler RAM, higher refresh rate means hotter * RAM. * * Throughout the driver, we use readl_relaxed() and writel_relaxed(), which * already contain the appropriate le32_to_cpu()/cpu_to_le32() calls. * * Note regarding the loading of the firmware image: we use be32_to_cpu() * and le_32_to_cpu(), so we can support the following four cases: * - LE kernel + LE firmware image (the most common case) * - LE kernel + BE firmware image * - BE kernel + LE firmware image * - BE kernel + BE firmware image * * The DPCU always runs in big endian mode. The firwmare image, however, can * be in either format. Also, communication between host CPU and DCPU is * always in little endian. */ #include <linux/delay.h> #include <linux/firmware.h> #include <linux/io.h> #include <linux/module.h> #include <linux/of_address.h> #include <linux/platform_device.h> #define DRVNAME "brcmstb-dpfe" #define FIRMWARE_NAME "dpfe.bin" /* DCPU register offsets */ #define REG_DCPU_RESET 0x0 #define REG_TO_DCPU_MBOX 0x10 #define REG_TO_HOST_MBOX 0x14 /* Macros to process offsets returned by the DCPU */ #define DRAM_MSG_ADDR_OFFSET 0x0 #define DRAM_MSG_TYPE_OFFSET 0x1c #define DRAM_MSG_ADDR_MASK ((1UL << DRAM_MSG_TYPE_OFFSET) - 1) #define DRAM_MSG_TYPE_MASK ((1UL << \ (BITS_PER_LONG - DRAM_MSG_TYPE_OFFSET)) - 1) /* Message RAM */ #define DCPU_MSG_RAM_START 0x100 #define DCPU_MSG_RAM(x) (DCPU_MSG_RAM_START + (x) * sizeof(u32)) /* DRAM Info Offsets & Masks */ #define DRAM_INFO_INTERVAL 0x0 #define DRAM_INFO_MR4 0x4 #define DRAM_INFO_ERROR 0x8 #define DRAM_INFO_MR4_MASK 0xff /* DRAM MR4 Offsets & Masks */ #define DRAM_MR4_REFRESH 0x0 /* Refresh rate */ #define DRAM_MR4_SR_ABORT 0x3 /* Self Refresh Abort */ #define DRAM_MR4_PPRE 0x4 /* Post-package repair entry/exit */ #define DRAM_MR4_TH_OFFS 0x5 /* Thermal Offset; vendor specific */ #define DRAM_MR4_TUF 0x7 /* Temperature Update Flag */ #define DRAM_MR4_REFRESH_MASK 0x7 #define DRAM_MR4_SR_ABORT_MASK 0x1 #define DRAM_MR4_PPRE_MASK 0x1 #define DRAM_MR4_TH_OFFS_MASK 0x3 #define DRAM_MR4_TUF_MASK 0x1 /* DRAM Vendor Offsets & Masks */ #define DRAM_VENDOR_MR5 0x0 #define DRAM_VENDOR_MR6 0x4 #define DRAM_VENDOR_MR7 0x8 #define DRAM_VENDOR_MR8 0xc #define DRAM_VENDOR_ERROR 0x10 #define DRAM_VENDOR_MASK 0xff /* Reset register bits & masks */ #define DCPU_RESET_SHIFT 0x0 #define DCPU_RESET_MASK 0x1 #define DCPU_CLK_DISABLE_SHIFT 0x2 /* DCPU return codes */ #define DCPU_RET_ERROR_BIT BIT(31) #define DCPU_RET_SUCCESS 0x1 #define DCPU_RET_ERR_HEADER (DCPU_RET_ERROR_BIT | BIT(0)) #define DCPU_RET_ERR_INVAL (DCPU_RET_ERROR_BIT | BIT(1)) #define DCPU_RET_ERR_CHKSUM (DCPU_RET_ERROR_BIT | BIT(2)) #define DCPU_RET_ERR_COMMAND (DCPU_RET_ERROR_BIT | BIT(3)) /* This error code is not firmware defined and only used in the driver. */ #define DCPU_RET_ERR_TIMEDOUT (DCPU_RET_ERROR_BIT | BIT(4)) /* Firmware magic */ #define DPFE_BE_MAGIC 0xfe1010fe #define DPFE_LE_MAGIC 0xfe0101fe /* Error codes */ #define ERR_INVALID_MAGIC -1 #define ERR_INVALID_SIZE -2 #define ERR_INVALID_CHKSUM -3 /* Message types */ #define DPFE_MSG_TYPE_COMMAND 1 #define DPFE_MSG_TYPE_RESPONSE 2 #define DELAY_LOOP_MAX 200000 enum dpfe_msg_fields { MSG_HEADER, MSG_COMMAND, MSG_ARG_COUNT, MSG_ARG0, MSG_CHKSUM, MSG_FIELD_MAX /* Last entry */ }; enum dpfe_commands { DPFE_CMD_GET_INFO, DPFE_CMD_GET_REFRESH, DPFE_CMD_GET_VENDOR, DPFE_CMD_MAX /* Last entry */ }; struct dpfe_msg { u32 header; u32 command; u32 arg_count; u32 arg0; u32 chksum; /* This is the sum of all other entries. */ }; /* * Format of the binary firmware file: * * entry * 0 header * value: 0xfe0101fe <== little endian * 0xfe1010fe <== big endian * 1 sequence: * [31:16] total segments on this build * [15:0] this segment sequence. * 2 FW version * 3 IMEM byte size * 4 DMEM byte size * IMEM * DMEM * last checksum ==> sum of everything */ struct dpfe_firmware_header { u32 magic; u32 sequence; u32 version; u32 imem_size; u32 dmem_size; }; /* Things we only need during initialization. */ struct init_data { unsigned int dmem_len; unsigned int imem_len; unsigned int chksum; bool is_big_endian; }; /* Things we need for as long as we are active. */ struct private_data { void __iomem *regs; void __iomem *dmem; void __iomem *imem; struct device *dev; unsigned int index; struct mutex lock; }; static const char *error_text[] = { "Success", "Header code incorrect", "Unknown command or argument", "Incorrect checksum", "Malformed command", "Timed out", }; /* List of supported firmware commands */ static const u32 dpfe_commands[DPFE_CMD_MAX][MSG_FIELD_MAX] = { [DPFE_CMD_GET_INFO] = { [MSG_HEADER] = DPFE_MSG_TYPE_COMMAND, [MSG_COMMAND] = 1, [MSG_ARG_COUNT] = 1, [MSG_ARG0] = 1, [MSG_CHKSUM] = 4, }, [DPFE_CMD_GET_REFRESH] = { [MSG_HEADER] = DPFE_MSG_TYPE_COMMAND, [MSG_COMMAND] = 2, [MSG_ARG_COUNT] = 1, [MSG_ARG0] = 1, [MSG_CHKSUM] = 5, }, [DPFE_CMD_GET_VENDOR] = { [MSG_HEADER] = DPFE_MSG_TYPE_COMMAND, [MSG_COMMAND] = 2, [MSG_ARG_COUNT] = 1, [MSG_ARG0] = 2, [MSG_CHKSUM] = 6, }, }; static bool is_dcpu_enabled(void __iomem *regs) { u32 val; val = readl_relaxed(regs + REG_DCPU_RESET); return !(val & DCPU_RESET_MASK); } static void __disable_dcpu(void __iomem *regs) { u32 val; if (!is_dcpu_enabled(regs)) return; /* Put DCPU in reset if it's running. */ val = readl_relaxed(regs + REG_DCPU_RESET); val |= (1 << DCPU_RESET_SHIFT); writel_relaxed(val, regs + REG_DCPU_RESET); } static void __enable_dcpu(void __iomem *regs) { u32 val; /* Clear mailbox registers. */ writel_relaxed(0, regs + REG_TO_DCPU_MBOX); writel_relaxed(0, regs + REG_TO_HOST_MBOX); /* Disable DCPU clock gating */ val = readl_relaxed(regs + REG_DCPU_RESET); val &= ~(1 << DCPU_CLK_DISABLE_SHIFT); writel_relaxed(val, regs + REG_DCPU_RESET); /* Take DCPU out of reset */ val = readl_relaxed(regs + REG_DCPU_RESET); val &= ~(1 << DCPU_RESET_SHIFT); writel_relaxed(val, regs + REG_DCPU_RESET); } static unsigned int get_msg_chksum(const u32 msg[]) { unsigned int sum = 0; unsigned int i; /* Don't include the last field in the checksum. */ for (i = 0; i < MSG_FIELD_MAX - 1; i++) sum += msg[i]; return sum; } static void __iomem *get_msg_ptr(struct private_data *priv, u32 response, char *buf, ssize_t *size) { unsigned int msg_type; unsigned int offset; void __iomem *ptr = NULL; msg_type = (response >> DRAM_MSG_TYPE_OFFSET) & DRAM_MSG_TYPE_MASK; offset = (response >> DRAM_MSG_ADDR_OFFSET) & DRAM_MSG_ADDR_MASK; /* * msg_type == 1: the offset is relative to the message RAM * msg_type == 0: the offset is relative to the data RAM (this is the * previous way of passing data) * msg_type is anything else: there's critical hardware problem */ switch (msg_type) { case 1: ptr = priv->regs + DCPU_MSG_RAM_START + offset; break; case 0: ptr = priv->dmem + offset; break; default: dev_emerg(priv->dev, "invalid message reply from DCPU: %#x\n", response); if (buf && size) *size = sprintf(buf, "FATAL: communication error with DCPU\n"); } return ptr; } static int __send_command(struct private_data *priv, unsigned int cmd, u32 result[]) { const u32 *msg = dpfe_commands[cmd]; void __iomem *regs = priv->regs; unsigned int i, chksum; int ret = 0; u32 resp; if (cmd >= DPFE_CMD_MAX) return -1; mutex_lock(&priv->lock); /* Write command and arguments to message area */ for (i = 0; i < MSG_FIELD_MAX; i++) writel_relaxed(msg[i], regs + DCPU_MSG_RAM(i)); /* Tell DCPU there is a command waiting */ writel_relaxed(1, regs + REG_TO_DCPU_MBOX); /* Wait for DCPU to process the command */ for (i = 0; i < DELAY_LOOP_MAX; i++) { /* Read response code */ resp = readl_relaxed(regs + REG_TO_HOST_MBOX); if (resp > 0) break; udelay(5); } if (i == DELAY_LOOP_MAX) { resp = (DCPU_RET_ERR_TIMEDOUT & ~DCPU_RET_ERROR_BIT); ret = -ffs(resp); } else { /* Read response data */ for (i = 0; i < MSG_FIELD_MAX; i++) result[i] = readl_relaxed(regs + DCPU_MSG_RAM(i)); } /* Tell DCPU we are done */ writel_relaxed(0, regs + REG_TO_HOST_MBOX); mutex_unlock(&priv->lock); if (ret) return ret; /* Verify response */ chksum = get_msg_chksum(result); if (chksum != result[MSG_CHKSUM]) resp = DCPU_RET_ERR_CHKSUM; if (resp != DCPU_RET_SUCCESS) { resp &= ~DCPU_RET_ERROR_BIT; ret = -ffs(resp); } return ret; } /* Ensure that the firmware file loaded meets all the requirements. */ static int __verify_firmware(struct init_data *init, const struct firmware *fw) { const struct dpfe_firmware_header *header = (void *)fw->data; unsigned int dmem_size, imem_size, total_size; bool is_big_endian = false; const u32 *chksum_ptr; if (header->magic == DPFE_BE_MAGIC) is_big_endian = true; else if (header->magic != DPFE_LE_MAGIC) return ERR_INVALID_MAGIC; if (is_big_endian) { dmem_size = be32_to_cpu(header->dmem_size); imem_size = be32_to_cpu(header->imem_size); } else { dmem_size = le32_to_cpu(header->dmem_size); imem_size = le32_to_cpu(header->imem_size); } /* Data and instruction sections are 32 bit words. */ if ((dmem_size % sizeof(u32)) != 0 || (imem_size % sizeof(u32)) != 0) return ERR_INVALID_SIZE; /* * The header + the data section + the instruction section + the * checksum must be equal to the total firmware size. */ total_size = dmem_size + imem_size + sizeof(*header) + sizeof(*chksum_ptr); if (total_size != fw->size) return ERR_INVALID_SIZE; /* The checksum comes at the very end. */ chksum_ptr = (void *)fw->data + sizeof(*header) + dmem_size + imem_size; init->is_big_endian = is_big_endian; init->dmem_len = dmem_size; init->imem_len = imem_size; init->chksum = (is_big_endian) ? be32_to_cpu(*chksum_ptr) : le32_to_cpu(*chksum_ptr); return 0; } /* Verify checksum by reading back the firmware from co-processor RAM. */ static int __verify_fw_checksum(struct init_data *init, struct private_data *priv, const struct dpfe_firmware_header *header, u32 checksum) { u32 magic, sequence, version, sum; u32 __iomem *dmem = priv->dmem; u32 __iomem *imem = priv->imem; unsigned int i; if (init->is_big_endian) { magic = be32_to_cpu(header->magic); sequence = be32_to_cpu(header->sequence); version = be32_to_cpu(header->version); } else { magic = le32_to_cpu(header->magic); sequence = le32_to_cpu(header->sequence); version = le32_to_cpu(header->version); } sum = magic + sequence + version + init->dmem_len + init->imem_len; for (i = 0; i < init->dmem_len / sizeof(u32); i++) sum += readl_relaxed(dmem + i); for (i = 0; i < init->imem_len / sizeof(u32); i++) sum += readl_relaxed(imem + i); return (sum == checksum) ? 0 : -1; } static int __write_firmware(u32 __iomem *mem, const u32 *fw, unsigned int size, bool is_big_endian) { unsigned int i; /* Convert size to 32-bit words. */ size /= sizeof(u32); /* It is recommended to clear the firmware area first. */ for (i = 0; i < size; i++) writel_relaxed(0, mem + i); /* Now copy it. */ if (is_big_endian) { for (i = 0; i < size; i++) writel_relaxed(be32_to_cpu(fw[i]), mem + i); } else { for (i = 0; i < size; i++) writel_relaxed(le32_to_cpu(fw[i]), mem + i); } return 0; } static int brcmstb_dpfe_download_firmware(struct platform_device *pdev, struct init_data *init) { const struct dpfe_firmware_header *header; unsigned int dmem_size, imem_size; struct device *dev = &pdev->dev; bool is_big_endian = false; struct private_data *priv; const struct firmware *fw; const u32 *dmem, *imem; const void *fw_blob; int ret; priv = platform_get_drvdata(pdev); /* * Skip downloading the firmware if the DCPU is already running and * responding to commands. */ if (is_dcpu_enabled(priv->regs)) { u32 response[MSG_FIELD_MAX]; ret = __send_command(priv, DPFE_CMD_GET_INFO, response); if (!ret) return 0; } ret = request_firmware(&fw, FIRMWARE_NAME, dev); /* request_firmware() prints its own error messages. */ if (ret) return ret; ret = __verify_firmware(init, fw); if (ret) return -EFAULT; __disable_dcpu(priv->regs); is_big_endian = init->is_big_endian; dmem_size = init->dmem_len; imem_size = init->imem_len; /* At the beginning of the firmware blob is a header. */ header = (struct dpfe_firmware_header *)fw->data; /* Void pointer to the beginning of the actual firmware. */ fw_blob = fw->data + sizeof(*header); /* IMEM comes right after the header. */ imem = fw_blob; /* DMEM follows after IMEM. */ dmem = fw_blob + imem_size; ret = __write_firmware(priv->dmem, dmem, dmem_size, is_big_endian); if (ret) return ret; ret = __write_firmware(priv->imem, imem, imem_size, is_big_endian); if (ret) return ret; ret = __verify_fw_checksum(init, priv, header, init->chksum); if (ret) return ret; __enable_dcpu(priv->regs); return 0; } static ssize_t generic_show(unsigned int command, u32 response[], struct device *dev, char *buf) { struct private_data *priv; int ret; priv = dev_get_drvdata(dev); if (!priv) return sprintf(buf, "ERROR: driver private data not set\n"); ret = __send_command(priv, command, response); if (ret < 0) return sprintf(buf, "ERROR: %s\n", error_text[-ret]); return 0; } static ssize_t show_info(struct device *dev, struct device_attribute *devattr, char *buf) { u32 response[MSG_FIELD_MAX]; unsigned int info; ssize_t ret; ret = generic_show(DPFE_CMD_GET_INFO, response, dev, buf); if (ret) return ret; info = response[MSG_ARG0]; return sprintf(buf, "%u.%u.%u.%u\n", (info >> 24) & 0xff, (info >> 16) & 0xff, (info >> 8) & 0xff, info & 0xff); } static ssize_t show_refresh(struct device *dev, struct device_attribute *devattr, char *buf) { u32 response[MSG_FIELD_MAX]; void __iomem *info; struct private_data *priv; u8 refresh, sr_abort, ppre, thermal_offs, tuf; u32 mr4; ssize_t ret; ret = generic_show(DPFE_CMD_GET_REFRESH, response, dev, buf); if (ret) return ret; priv = dev_get_drvdata(dev); info = get_msg_ptr(priv, response[MSG_ARG0], buf, &ret); if (!info) return ret; mr4 = readl_relaxed(info + DRAM_INFO_MR4) & DRAM_INFO_MR4_MASK; refresh = (mr4 >> DRAM_MR4_REFRESH) & DRAM_MR4_REFRESH_MASK; sr_abort = (mr4 >> DRAM_MR4_SR_ABORT) & DRAM_MR4_SR_ABORT_MASK; ppre = (mr4 >> DRAM_MR4_PPRE) & DRAM_MR4_PPRE_MASK; thermal_offs = (mr4 >> DRAM_MR4_TH_OFFS) & DRAM_MR4_TH_OFFS_MASK; tuf = (mr4 >> DRAM_MR4_TUF) & DRAM_MR4_TUF_MASK; return sprintf(buf, "%#x %#x %#x %#x %#x %#x %#x\n", readl_relaxed(info + DRAM_INFO_INTERVAL), refresh, sr_abort, ppre, thermal_offs, tuf, readl_relaxed(info + DRAM_INFO_ERROR)); } static ssize_t store_refresh(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) { u32 response[MSG_FIELD_MAX]; struct private_data *priv; void __iomem *info; unsigned long val; int ret; if (kstrtoul(buf, 0, &val) < 0) return -EINVAL; priv = dev_get_drvdata(dev); ret = __send_command(priv, DPFE_CMD_GET_REFRESH, response); if (ret) return ret; info = get_msg_ptr(priv, response[MSG_ARG0], NULL, NULL); if (!info) return -EIO; writel_relaxed(val, info + DRAM_INFO_INTERVAL); return count; } static ssize_t show_vendor(struct device *dev, struct device_attribute *devattr, char *buf) { u32 response[MSG_FIELD_MAX]; struct private_data *priv; void __iomem *info; ssize_t ret; ret = generic_show(DPFE_CMD_GET_VENDOR, response, dev, buf); if (ret) return ret; priv = dev_get_drvdata(dev); info = get_msg_ptr(priv, response[MSG_ARG0], buf, &ret); if (!info) return ret; return sprintf(buf, "%#x %#x %#x %#x %#x\n", readl_relaxed(info + DRAM_VENDOR_MR5) & DRAM_VENDOR_MASK, readl_relaxed(info + DRAM_VENDOR_MR6) & DRAM_VENDOR_MASK, readl_relaxed(info + DRAM_VENDOR_MR7) & DRAM_VENDOR_MASK, readl_relaxed(info + DRAM_VENDOR_MR8) & DRAM_VENDOR_MASK, readl_relaxed(info + DRAM_VENDOR_ERROR) & DRAM_VENDOR_MASK); } static int brcmstb_dpfe_resume(struct platform_device *pdev) { struct init_data init; return brcmstb_dpfe_download_firmware(pdev, &init); } static DEVICE_ATTR(dpfe_info, 0444, show_info, NULL); static DEVICE_ATTR(dpfe_refresh, 0644, show_refresh, store_refresh); static DEVICE_ATTR(dpfe_vendor, 0444, show_vendor, NULL); static struct attribute *dpfe_attrs[] = { &dev_attr_dpfe_info.attr, &dev_attr_dpfe_refresh.attr, &dev_attr_dpfe_vendor.attr, NULL }; ATTRIBUTE_GROUPS(dpfe); static int brcmstb_dpfe_probe(struct platform_device *pdev) { struct device *dev = &pdev->dev; struct private_data *priv; struct device *dpfe_dev; struct init_data init; struct resource *res; u32 index; int ret; priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL); if (!priv) return -ENOMEM; mutex_init(&priv->lock); platform_set_drvdata(pdev, priv); /* Cell index is optional; default to 0 if not present. */ ret = of_property_read_u32(dev->of_node, "cell-index", &index); if (ret) index = 0; res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "dpfe-cpu"); priv->regs = devm_ioremap_resource(dev, res); if (IS_ERR(priv->regs)) { dev_err(dev, "couldn't map DCPU registers\n"); return -ENODEV; } res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "dpfe-dmem"); priv->dmem = devm_ioremap_resource(dev, res); if (IS_ERR(priv->dmem)) { dev_err(dev, "Couldn't map DCPU data memory\n"); return -ENOENT; } res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "dpfe-imem"); priv->imem = devm_ioremap_resource(dev, res); if (IS_ERR(priv->imem)) { dev_err(dev, "Couldn't map DCPU instruction memory\n"); return -ENOENT; } ret = brcmstb_dpfe_download_firmware(pdev, &init); if (ret) goto err; dpfe_dev = devm_kzalloc(dev, sizeof(*dpfe_dev), GFP_KERNEL); if (!dpfe_dev) { ret = -ENOMEM; goto err; } priv->dev = dpfe_dev; priv->index = index; dpfe_dev->parent = dev; dpfe_dev->groups = dpfe_groups; dpfe_dev->of_node = dev->of_node; dev_set_drvdata(dpfe_dev, priv); dev_set_name(dpfe_dev, "dpfe%u", index); ret = device_register(dpfe_dev); if (ret) goto err; dev_info(dev, "registered.\n"); return 0; err: dev_err(dev, "failed to initialize -- error %d\n", ret); return ret; } static const struct of_device_id brcmstb_dpfe_of_match[] = { { .compatible = "brcm,dpfe-cpu", }, {} }; MODULE_DEVICE_TABLE(of, brcmstb_dpfe_of_match); static struct platform_driver brcmstb_dpfe_driver = { .driver = { .name = DRVNAME, .of_match_table = brcmstb_dpfe_of_match, }, .probe = brcmstb_dpfe_probe, .resume = brcmstb_dpfe_resume, }; module_platform_driver(brcmstb_dpfe_driver); MODULE_AUTHOR("Markus Mayer <mmayer@broadcom.com>"); MODULE_DESCRIPTION("BRCMSTB DDR PHY Front End Driver"); MODULE_LICENSE("GPL");