diff options
Diffstat (limited to 'drivers/memory/brcmstb_dpfe.c')
| -rw-r--r-- | drivers/memory/brcmstb_dpfe.c | 701 |
1 files changed, 701 insertions, 0 deletions
diff --git a/drivers/memory/brcmstb_dpfe.c b/drivers/memory/brcmstb_dpfe.c new file mode 100644 index 000000000000..21242c401af5 --- /dev/null +++ b/drivers/memory/brcmstb_dpfe.c @@ -0,0 +1,701 @@ +/* + * 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 + +/* Message RAM */ +#define DCPU_MSG_RAM(x) (0x100 + (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 void __disable_dcpu(void __iomem *regs) +{ + u32 val; + + /* Check if DCPU is running */ + val = readl_relaxed(regs + REG_DCPU_RESET); + if (!(val & DCPU_RESET_MASK)) { + /* Put DCPU in 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 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; + + ret = request_firmware(&fw, FIRMWARE_NAME, dev); + /* request_firmware() prints its own error messages. */ + if (ret) + return ret; + + priv = platform_get_drvdata(pdev); + + 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; + int 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; + unsigned int offset; + u8 refresh, sr_abort, ppre, thermal_offs, tuf; + u32 mr4; + int ret; + + ret = generic_show(DPFE_CMD_GET_REFRESH, response, dev, buf); + if (ret) + return ret; + + priv = dev_get_drvdata(dev); + offset = response[MSG_ARG0]; + info = priv->dmem + offset; + + 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 int offset; + 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; + + offset = response[MSG_ARG0]; + info = priv->dmem + offset; + 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; + unsigned int offset; + int ret; + + ret = generic_show(DPFE_CMD_GET_VENDOR, response, dev, buf); + if (ret) + return ret; + + offset = response[MSG_ARG0]; + priv = dev_get_drvdata(dev); + info = priv->dmem + offset; + + 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)); +} + +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"); |