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drivers/spi/spi-bcm53xx.c
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81f7e3824 Initial Release, ... |
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/* * 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 "); } 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! "); 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 "); 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 ", 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"); |