|  | /* | 
|  | * Copyright (C) 2014-2016 Rafał Miłecki <rafal@milecki.pl> | 
|  | * | 
|  | * This program is free software; you can redistribute it and/or modify | 
|  | * it under the terms of the GNU General Public License version 2 as | 
|  | * published by the Free Software Foundation. | 
|  | */ | 
|  |  | 
|  | #define pr_fmt(fmt)		KBUILD_MODNAME ": " fmt | 
|  |  | 
|  | #include <linux/kernel.h> | 
|  | #include <linux/module.h> | 
|  | #include <linux/slab.h> | 
|  | #include <linux/delay.h> | 
|  | #include <linux/bcma/bcma.h> | 
|  | #include <linux/spi/spi.h> | 
|  |  | 
|  | #include "spi-bcm53xx.h" | 
|  |  | 
|  | #define BCM53XXSPI_MAX_SPI_BAUD	13500000	/* 216 MHz? */ | 
|  | #define BCM53XXSPI_FLASH_WINDOW	SZ_32M | 
|  |  | 
|  | /* The longest observed required wait was 19 ms */ | 
|  | #define BCM53XXSPI_SPE_TIMEOUT_MS	80 | 
|  |  | 
|  | struct bcm53xxspi { | 
|  | struct bcma_device *core; | 
|  | struct spi_master *master; | 
|  | void __iomem *mmio_base; | 
|  |  | 
|  | size_t read_offset; | 
|  | bool bspi;				/* Boot SPI mode with memory mapping */ | 
|  | }; | 
|  |  | 
|  | static inline u32 bcm53xxspi_read(struct bcm53xxspi *b53spi, u16 offset) | 
|  | { | 
|  | return bcma_read32(b53spi->core, offset); | 
|  | } | 
|  |  | 
|  | static inline void bcm53xxspi_write(struct bcm53xxspi *b53spi, u16 offset, | 
|  | u32 value) | 
|  | { | 
|  | bcma_write32(b53spi->core, offset, value); | 
|  | } | 
|  |  | 
|  | static void bcm53xxspi_disable_bspi(struct bcm53xxspi *b53spi) | 
|  | { | 
|  | struct device *dev = &b53spi->core->dev; | 
|  | unsigned long deadline; | 
|  | u32 tmp; | 
|  |  | 
|  | if (!b53spi->bspi) | 
|  | return; | 
|  |  | 
|  | tmp = bcm53xxspi_read(b53spi, B53SPI_BSPI_MAST_N_BOOT_CTRL); | 
|  | if (tmp & 0x1) | 
|  | return; | 
|  |  | 
|  | deadline = jiffies + usecs_to_jiffies(200); | 
|  | do { | 
|  | tmp = bcm53xxspi_read(b53spi, B53SPI_BSPI_BUSY_STATUS); | 
|  | if (!(tmp & 0x1)) { | 
|  | bcm53xxspi_write(b53spi, B53SPI_BSPI_MAST_N_BOOT_CTRL, | 
|  | 0x1); | 
|  | ndelay(200); | 
|  | b53spi->bspi = false; | 
|  | return; | 
|  | } | 
|  | udelay(1); | 
|  | } while (!time_after_eq(jiffies, deadline)); | 
|  |  | 
|  | dev_warn(dev, "Timeout disabling BSPI\n"); | 
|  | } | 
|  |  | 
|  | static void bcm53xxspi_enable_bspi(struct bcm53xxspi *b53spi) | 
|  | { | 
|  | u32 tmp; | 
|  |  | 
|  | if (b53spi->bspi) | 
|  | return; | 
|  |  | 
|  | tmp = bcm53xxspi_read(b53spi, B53SPI_BSPI_MAST_N_BOOT_CTRL); | 
|  | if (!(tmp & 0x1)) | 
|  | return; | 
|  |  | 
|  | bcm53xxspi_write(b53spi, B53SPI_BSPI_MAST_N_BOOT_CTRL, 0x0); | 
|  | b53spi->bspi = true; | 
|  | } | 
|  |  | 
|  | static inline unsigned int bcm53xxspi_calc_timeout(size_t len) | 
|  | { | 
|  | /* Do some magic calculation based on length and buad. Add 10% and 1. */ | 
|  | return (len * 9000 / BCM53XXSPI_MAX_SPI_BAUD * 110 / 100) + 1; | 
|  | } | 
|  |  | 
|  | static int bcm53xxspi_wait(struct bcm53xxspi *b53spi, unsigned int timeout_ms) | 
|  | { | 
|  | unsigned long deadline; | 
|  | u32 tmp; | 
|  |  | 
|  | /* SPE bit has to be 0 before we read MSPI STATUS */ | 
|  | deadline = jiffies + msecs_to_jiffies(BCM53XXSPI_SPE_TIMEOUT_MS); | 
|  | do { | 
|  | tmp = bcm53xxspi_read(b53spi, B53SPI_MSPI_SPCR2); | 
|  | if (!(tmp & B53SPI_MSPI_SPCR2_SPE)) | 
|  | break; | 
|  | udelay(5); | 
|  | } while (!time_after_eq(jiffies, deadline)); | 
|  |  | 
|  | if (tmp & B53SPI_MSPI_SPCR2_SPE) | 
|  | goto spi_timeout; | 
|  |  | 
|  | /* Check status */ | 
|  | deadline = jiffies + msecs_to_jiffies(timeout_ms); | 
|  | do { | 
|  | tmp = bcm53xxspi_read(b53spi, B53SPI_MSPI_MSPI_STATUS); | 
|  | if (tmp & B53SPI_MSPI_MSPI_STATUS_SPIF) { | 
|  | bcm53xxspi_write(b53spi, B53SPI_MSPI_MSPI_STATUS, 0); | 
|  | return 0; | 
|  | } | 
|  |  | 
|  | cpu_relax(); | 
|  | udelay(100); | 
|  | } while (!time_after_eq(jiffies, deadline)); | 
|  |  | 
|  | spi_timeout: | 
|  | bcm53xxspi_write(b53spi, B53SPI_MSPI_MSPI_STATUS, 0); | 
|  |  | 
|  | pr_err("Timeout waiting for SPI to be ready!\n"); | 
|  |  | 
|  | return -EBUSY; | 
|  | } | 
|  |  | 
|  | static void bcm53xxspi_buf_write(struct bcm53xxspi *b53spi, u8 *w_buf, | 
|  | size_t len, bool cont) | 
|  | { | 
|  | u32 tmp; | 
|  | int i; | 
|  |  | 
|  | for (i = 0; i < len; i++) { | 
|  | /* Transmit Register File MSB */ | 
|  | bcm53xxspi_write(b53spi, B53SPI_MSPI_TXRAM + 4 * (i * 2), | 
|  | (unsigned int)w_buf[i]); | 
|  | } | 
|  |  | 
|  | for (i = 0; i < len; i++) { | 
|  | tmp = B53SPI_CDRAM_CONT | B53SPI_CDRAM_PCS_DISABLE_ALL | | 
|  | B53SPI_CDRAM_PCS_DSCK; | 
|  | if (!cont && i == len - 1) | 
|  | tmp &= ~B53SPI_CDRAM_CONT; | 
|  | tmp &= ~0x1; | 
|  | /* Command Register File */ | 
|  | bcm53xxspi_write(b53spi, B53SPI_MSPI_CDRAM + 4 * i, tmp); | 
|  | } | 
|  |  | 
|  | /* Set queue pointers */ | 
|  | bcm53xxspi_write(b53spi, B53SPI_MSPI_NEWQP, 0); | 
|  | bcm53xxspi_write(b53spi, B53SPI_MSPI_ENDQP, len - 1); | 
|  |  | 
|  | if (cont) | 
|  | bcm53xxspi_write(b53spi, B53SPI_MSPI_WRITE_LOCK, 1); | 
|  |  | 
|  | /* Start SPI transfer */ | 
|  | tmp = bcm53xxspi_read(b53spi, B53SPI_MSPI_SPCR2); | 
|  | tmp |= B53SPI_MSPI_SPCR2_SPE; | 
|  | if (cont) | 
|  | tmp |= B53SPI_MSPI_SPCR2_CONT_AFTER_CMD; | 
|  | bcm53xxspi_write(b53spi, B53SPI_MSPI_SPCR2, tmp); | 
|  |  | 
|  | /* Wait for SPI to finish */ | 
|  | bcm53xxspi_wait(b53spi, bcm53xxspi_calc_timeout(len)); | 
|  |  | 
|  | if (!cont) | 
|  | bcm53xxspi_write(b53spi, B53SPI_MSPI_WRITE_LOCK, 0); | 
|  |  | 
|  | b53spi->read_offset = len; | 
|  | } | 
|  |  | 
|  | static void bcm53xxspi_buf_read(struct bcm53xxspi *b53spi, u8 *r_buf, | 
|  | size_t len, bool cont) | 
|  | { | 
|  | u32 tmp; | 
|  | int i; | 
|  |  | 
|  | for (i = 0; i < b53spi->read_offset + len; i++) { | 
|  | tmp = B53SPI_CDRAM_CONT | B53SPI_CDRAM_PCS_DISABLE_ALL | | 
|  | B53SPI_CDRAM_PCS_DSCK; | 
|  | if (!cont && i == b53spi->read_offset + len - 1) | 
|  | tmp &= ~B53SPI_CDRAM_CONT; | 
|  | tmp &= ~0x1; | 
|  | /* Command Register File */ | 
|  | bcm53xxspi_write(b53spi, B53SPI_MSPI_CDRAM + 4 * i, tmp); | 
|  | } | 
|  |  | 
|  | /* Set queue pointers */ | 
|  | bcm53xxspi_write(b53spi, B53SPI_MSPI_NEWQP, 0); | 
|  | bcm53xxspi_write(b53spi, B53SPI_MSPI_ENDQP, | 
|  | b53spi->read_offset + len - 1); | 
|  |  | 
|  | if (cont) | 
|  | bcm53xxspi_write(b53spi, B53SPI_MSPI_WRITE_LOCK, 1); | 
|  |  | 
|  | /* Start SPI transfer */ | 
|  | tmp = bcm53xxspi_read(b53spi, B53SPI_MSPI_SPCR2); | 
|  | tmp |= B53SPI_MSPI_SPCR2_SPE; | 
|  | if (cont) | 
|  | tmp |= B53SPI_MSPI_SPCR2_CONT_AFTER_CMD; | 
|  | bcm53xxspi_write(b53spi, B53SPI_MSPI_SPCR2, tmp); | 
|  |  | 
|  | /* Wait for SPI to finish */ | 
|  | bcm53xxspi_wait(b53spi, bcm53xxspi_calc_timeout(len)); | 
|  |  | 
|  | if (!cont) | 
|  | bcm53xxspi_write(b53spi, B53SPI_MSPI_WRITE_LOCK, 0); | 
|  |  | 
|  | for (i = 0; i < len; ++i) { | 
|  | int offset = b53spi->read_offset + i; | 
|  |  | 
|  | /* Data stored in the transmit register file LSB */ | 
|  | r_buf[i] = (u8)bcm53xxspi_read(b53spi, B53SPI_MSPI_RXRAM + 4 * (1 + offset * 2)); | 
|  | } | 
|  |  | 
|  | b53spi->read_offset = 0; | 
|  | } | 
|  |  | 
|  | static int bcm53xxspi_transfer_one(struct spi_master *master, | 
|  | struct spi_device *spi, | 
|  | struct spi_transfer *t) | 
|  | { | 
|  | struct bcm53xxspi *b53spi = spi_master_get_devdata(master); | 
|  | u8 *buf; | 
|  | size_t left; | 
|  |  | 
|  | bcm53xxspi_disable_bspi(b53spi); | 
|  |  | 
|  | if (t->tx_buf) { | 
|  | buf = (u8 *)t->tx_buf; | 
|  | left = t->len; | 
|  | while (left) { | 
|  | size_t to_write = min_t(size_t, 16, left); | 
|  | bool cont = left - to_write > 0; | 
|  |  | 
|  | bcm53xxspi_buf_write(b53spi, buf, to_write, cont); | 
|  | left -= to_write; | 
|  | buf += to_write; | 
|  | } | 
|  | } | 
|  |  | 
|  | if (t->rx_buf) { | 
|  | buf = (u8 *)t->rx_buf; | 
|  | left = t->len; | 
|  | while (left) { | 
|  | size_t to_read = min_t(size_t, 16 - b53spi->read_offset, | 
|  | left); | 
|  | bool cont = left - to_read > 0; | 
|  |  | 
|  | bcm53xxspi_buf_read(b53spi, buf, to_read, cont); | 
|  | left -= to_read; | 
|  | buf += to_read; | 
|  | } | 
|  | } | 
|  |  | 
|  | return 0; | 
|  | } | 
|  |  | 
|  | static int bcm53xxspi_flash_read(struct spi_device *spi, | 
|  | struct spi_flash_read_message *msg) | 
|  | { | 
|  | struct bcm53xxspi *b53spi = spi_master_get_devdata(spi->master); | 
|  | int ret = 0; | 
|  |  | 
|  | if (msg->from + msg->len > BCM53XXSPI_FLASH_WINDOW) | 
|  | return -EINVAL; | 
|  |  | 
|  | bcm53xxspi_enable_bspi(b53spi); | 
|  | memcpy_fromio(msg->buf, b53spi->mmio_base + msg->from, msg->len); | 
|  | msg->retlen = msg->len; | 
|  |  | 
|  | return ret; | 
|  | } | 
|  |  | 
|  | /************************************************** | 
|  | * BCMA | 
|  | **************************************************/ | 
|  |  | 
|  | static const struct bcma_device_id bcm53xxspi_bcma_tbl[] = { | 
|  | BCMA_CORE(BCMA_MANUF_BCM, BCMA_CORE_NS_QSPI, BCMA_ANY_REV, BCMA_ANY_CLASS), | 
|  | {}, | 
|  | }; | 
|  | MODULE_DEVICE_TABLE(bcma, bcm53xxspi_bcma_tbl); | 
|  |  | 
|  | static int bcm53xxspi_bcma_probe(struct bcma_device *core) | 
|  | { | 
|  | struct device *dev = &core->dev; | 
|  | struct bcm53xxspi *b53spi; | 
|  | struct spi_master *master; | 
|  | int err; | 
|  |  | 
|  | if (core->bus->drv_cc.core->id.rev != 42) { | 
|  | pr_err("SPI on SoC with unsupported ChipCommon rev\n"); | 
|  | return -ENOTSUPP; | 
|  | } | 
|  |  | 
|  | master = spi_alloc_master(dev, sizeof(*b53spi)); | 
|  | if (!master) | 
|  | return -ENOMEM; | 
|  |  | 
|  | b53spi = spi_master_get_devdata(master); | 
|  | b53spi->master = master; | 
|  | b53spi->core = core; | 
|  |  | 
|  | if (core->addr_s[0]) | 
|  | b53spi->mmio_base = devm_ioremap(dev, core->addr_s[0], | 
|  | BCM53XXSPI_FLASH_WINDOW); | 
|  | b53spi->bspi = true; | 
|  | bcm53xxspi_disable_bspi(b53spi); | 
|  |  | 
|  | master->dev.of_node = dev->of_node; | 
|  | master->transfer_one = bcm53xxspi_transfer_one; | 
|  | if (b53spi->mmio_base) | 
|  | master->spi_flash_read = bcm53xxspi_flash_read; | 
|  |  | 
|  | bcma_set_drvdata(core, b53spi); | 
|  |  | 
|  | err = devm_spi_register_master(dev, master); | 
|  | if (err) { | 
|  | spi_master_put(master); | 
|  | bcma_set_drvdata(core, NULL); | 
|  | return err; | 
|  | } | 
|  |  | 
|  | return 0; | 
|  | } | 
|  |  | 
|  | static struct bcma_driver bcm53xxspi_bcma_driver = { | 
|  | .name		= KBUILD_MODNAME, | 
|  | .id_table	= bcm53xxspi_bcma_tbl, | 
|  | .probe		= bcm53xxspi_bcma_probe, | 
|  | }; | 
|  |  | 
|  | /************************************************** | 
|  | * Init & exit | 
|  | **************************************************/ | 
|  |  | 
|  | static int __init bcm53xxspi_module_init(void) | 
|  | { | 
|  | int err = 0; | 
|  |  | 
|  | err = bcma_driver_register(&bcm53xxspi_bcma_driver); | 
|  | if (err) | 
|  | pr_err("Failed to register bcma driver: %d\n", err); | 
|  |  | 
|  | return err; | 
|  | } | 
|  |  | 
|  | static void __exit bcm53xxspi_module_exit(void) | 
|  | { | 
|  | bcma_driver_unregister(&bcm53xxspi_bcma_driver); | 
|  | } | 
|  |  | 
|  | module_init(bcm53xxspi_module_init); | 
|  | module_exit(bcm53xxspi_module_exit); | 
|  |  | 
|  | MODULE_DESCRIPTION("Broadcom BCM53xx SPI Controller driver"); | 
|  | MODULE_AUTHOR("Rafał Miłecki <zajec5@gmail.com>"); | 
|  | MODULE_LICENSE("GPL v2"); |