/* * Freescale eSPI controller driver. * * Copyright 2010 Freescale Semiconductor, Inc. * * This program is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License as published by the * Free Software Foundation; either version 2 of the License, or (at your * option) any later version. */ #include <linux/module.h> #include <linux/delay.h> #include <linux/irq.h> #include <linux/spi/spi.h> #include <linux/platform_device.h> #include <linux/fsl_devices.h> #include <linux/mm.h> #include <linux/of.h> #include <linux/of_platform.h> #include <linux/interrupt.h> #include <linux/err.h> #include <sysdev/fsl_soc.h> #include "spi-fsl-lib.h" /* eSPI Controller registers */ struct fsl_espi_reg { __be32 mode; /* 0x000 - eSPI mode register */ __be32 event; /* 0x004 - eSPI event register */ __be32 mask; /* 0x008 - eSPI mask register */ __be32 command; /* 0x00c - eSPI command register */ __be32 transmit; /* 0x010 - eSPI transmit FIFO access register*/ __be32 receive; /* 0x014 - eSPI receive FIFO access register*/ u8 res[8]; /* 0x018 - 0x01c reserved */ __be32 csmode[4]; /* 0x020 - 0x02c eSPI cs mode register */ }; struct fsl_espi_transfer { const void *tx_buf; void *rx_buf; unsigned len; unsigned n_tx; unsigned n_rx; unsigned actual_length; int status; }; /* eSPI Controller mode register definitions */ #define SPMODE_ENABLE (1 << 31) #define SPMODE_LOOP (1 << 30) #define SPMODE_TXTHR(x) ((x) << 8) #define SPMODE_RXTHR(x) ((x) << 0) /* eSPI Controller CS mode register definitions */ #define CSMODE_CI_INACTIVEHIGH (1 << 31) #define CSMODE_CP_BEGIN_EDGECLK (1 << 30) #define CSMODE_REV (1 << 29) #define CSMODE_DIV16 (1 << 28) #define CSMODE_PM(x) ((x) << 24) #define CSMODE_POL_1 (1 << 20) #define CSMODE_LEN(x) ((x) << 16) #define CSMODE_BEF(x) ((x) << 12) #define CSMODE_AFT(x) ((x) << 8) #define CSMODE_CG(x) ((x) << 3) /* Default mode/csmode for eSPI controller */ #define SPMODE_INIT_VAL (SPMODE_TXTHR(4) | SPMODE_RXTHR(3)) #define CSMODE_INIT_VAL (CSMODE_POL_1 | CSMODE_BEF(0) \ | CSMODE_AFT(0) | CSMODE_CG(1)) /* SPIE register values */ #define SPIE_NE 0x00000200 /* Not empty */ #define SPIE_NF 0x00000100 /* Not full */ /* SPIM register values */ #define SPIM_NE 0x00000200 /* Not empty */ #define SPIM_NF 0x00000100 /* Not full */ #define SPIE_RXCNT(reg) ((reg >> 24) & 0x3F) #define SPIE_TXCNT(reg) ((reg >> 16) & 0x3F) /* SPCOM register values */ #define SPCOM_CS(x) ((x) << 30) #define SPCOM_TRANLEN(x) ((x) << 0) #define SPCOM_TRANLEN_MAX 0xFFFF /* Max transaction length */ static void fsl_espi_change_mode(struct spi_device *spi) { struct mpc8xxx_spi *mspi = spi_master_get_devdata(spi->master); struct spi_mpc8xxx_cs *cs = spi->controller_state; struct fsl_espi_reg *reg_base = mspi->reg_base; __be32 __iomem *mode = ®_base->csmode[spi->chip_select]; __be32 __iomem *espi_mode = ®_base->mode; u32 tmp; unsigned long flags; /* Turn off IRQs locally to minimize time that SPI is disabled. */ local_irq_save(flags); /* Turn off SPI unit prior changing mode */ tmp = mpc8xxx_spi_read_reg(espi_mode); mpc8xxx_spi_write_reg(espi_mode, tmp & ~SPMODE_ENABLE); mpc8xxx_spi_write_reg(mode, cs->hw_mode); mpc8xxx_spi_write_reg(espi_mode, tmp); local_irq_restore(flags); } static u32 fsl_espi_tx_buf_lsb(struct mpc8xxx_spi *mpc8xxx_spi) { u32 data; u16 data_h; u16 data_l; const u32 *tx = mpc8xxx_spi->tx; if (!tx) return 0; data = *tx++ << mpc8xxx_spi->tx_shift; data_l = data & 0xffff; data_h = (data >> 16) & 0xffff; swab16s(&data_l); swab16s(&data_h); data = data_h | data_l; mpc8xxx_spi->tx = tx; return data; } static int fsl_espi_setup_transfer(struct spi_device *spi, struct spi_transfer *t) { struct mpc8xxx_spi *mpc8xxx_spi = spi_master_get_devdata(spi->master); int bits_per_word = 0; u8 pm; u32 hz = 0; struct spi_mpc8xxx_cs *cs = spi->controller_state; if (t) { bits_per_word = t->bits_per_word; hz = t->speed_hz; } /* spi_transfer level calls that work per-word */ if (!bits_per_word) bits_per_word = spi->bits_per_word; /* Make sure its a bit width we support [4..16] */ if ((bits_per_word < 4) || (bits_per_word > 16)) return -EINVAL; if (!hz) hz = spi->max_speed_hz; cs->rx_shift = 0; cs->tx_shift = 0; cs->get_rx = mpc8xxx_spi_rx_buf_u32; cs->get_tx = mpc8xxx_spi_tx_buf_u32; if (bits_per_word <= 8) { cs->rx_shift = 8 - bits_per_word; } else if (bits_per_word <= 16) { cs->rx_shift = 16 - bits_per_word; if (spi->mode & SPI_LSB_FIRST) cs->get_tx = fsl_espi_tx_buf_lsb; } else { return -EINVAL; } mpc8xxx_spi->rx_shift = cs->rx_shift; mpc8xxx_spi->tx_shift = cs->tx_shift; mpc8xxx_spi->get_rx = cs->get_rx; mpc8xxx_spi->get_tx = cs->get_tx; bits_per_word = bits_per_word - 1; /* mask out bits we are going to set */ cs->hw_mode &= ~(CSMODE_LEN(0xF) | CSMODE_DIV16 | CSMODE_PM(0xF)); cs->hw_mode |= CSMODE_LEN(bits_per_word); if ((mpc8xxx_spi->spibrg / hz) > 64) { cs->hw_mode |= CSMODE_DIV16; pm = DIV_ROUND_UP(mpc8xxx_spi->spibrg, hz * 16 * 4); WARN_ONCE(pm > 33, "%s: Requested speed is too low: %d Hz. " "Will use %d Hz instead.\n", dev_name(&spi->dev), hz, mpc8xxx_spi->spibrg / (4 * 16 * (32 + 1))); if (pm > 33) pm = 33; } else { pm = DIV_ROUND_UP(mpc8xxx_spi->spibrg, hz * 4); } if (pm) pm--; if (pm < 2) pm = 2; cs->hw_mode |= CSMODE_PM(pm); fsl_espi_change_mode(spi); return 0; } static int fsl_espi_cpu_bufs(struct mpc8xxx_spi *mspi, struct spi_transfer *t, unsigned int len) { u32 word; struct fsl_espi_reg *reg_base = mspi->reg_base; mspi->count = len; /* enable rx ints */ mpc8xxx_spi_write_reg(®_base->mask, SPIM_NE); /* transmit word */ word = mspi->get_tx(mspi); mpc8xxx_spi_write_reg(®_base->transmit, word); return 0; } static int fsl_espi_bufs(struct spi_device *spi, struct spi_transfer *t) { struct mpc8xxx_spi *mpc8xxx_spi = spi_master_get_devdata(spi->master); struct fsl_espi_reg *reg_base = mpc8xxx_spi->reg_base; unsigned int len = t->len; u8 bits_per_word; int ret; bits_per_word = spi->bits_per_word; if (t->bits_per_word) bits_per_word = t->bits_per_word; mpc8xxx_spi->len = t->len; len = roundup(len, 4) / 4; mpc8xxx_spi->tx = t->tx_buf; mpc8xxx_spi->rx = t->rx_buf; INIT_COMPLETION(mpc8xxx_spi->done); /* Set SPCOM[CS] and SPCOM[TRANLEN] field */ if ((t->len - 1) > SPCOM_TRANLEN_MAX) { dev_err(mpc8xxx_spi->dev, "Transaction length (%d)" " beyond the SPCOM[TRANLEN] field\n", t->len); return -EINVAL; } mpc8xxx_spi_write_reg(®_base->command, (SPCOM_CS(spi->chip_select) | SPCOM_TRANLEN(t->len - 1))); ret = fsl_espi_cpu_bufs(mpc8xxx_spi, t, len); if (ret) return ret; wait_for_completion(&mpc8xxx_spi->done); /* disable rx ints */ mpc8xxx_spi_write_reg(®_base->mask, 0); return mpc8xxx_spi->count; } static inline void fsl_espi_addr2cmd(unsigned int addr, u8 *cmd) { if (cmd) { cmd[1] = (u8)(addr >> 16); cmd[2] = (u8)(addr >> 8); cmd[3] = (u8)(addr >> 0); } } static inline unsigned int fsl_espi_cmd2addr(u8 *cmd) { if (cmd) return cmd[1] << 16 | cmd[2] << 8 | cmd[3] << 0; return 0; } static void fsl_espi_do_trans(struct spi_message *m, struct fsl_espi_transfer *tr) { struct spi_device *spi = m->spi; struct mpc8xxx_spi *mspi = spi_master_get_devdata(spi->master); struct fsl_espi_transfer *espi_trans = tr; struct spi_message message; struct spi_transfer *t, *first, trans; int status = 0; spi_message_init(&message); memset(&trans, 0, sizeof(trans)); first = list_first_entry(&m->transfers, struct spi_transfer, transfer_list); list_for_each_entry(t, &m->transfers, transfer_list) { if ((first->bits_per_word != t->bits_per_word) || (first->speed_hz != t->speed_hz)) { espi_trans->status = -EINVAL; dev_err(mspi->dev, "bits_per_word/speed_hz should be" " same for the same SPI transfer\n"); return; } trans.speed_hz = t->speed_hz; trans.bits_per_word = t->bits_per_word; trans.delay_usecs = max(first->delay_usecs, t->delay_usecs); } trans.len = espi_trans->len; trans.tx_buf = espi_trans->tx_buf; trans.rx_buf = espi_trans->rx_buf; spi_message_add_tail(&trans, &message); list_for_each_entry(t, &message.transfers, transfer_list) { if (t->bits_per_word || t->speed_hz) { status = -EINVAL; status = fsl_espi_setup_transfer(spi, t); if (status < 0) break; } if (t->len) status = fsl_espi_bufs(spi, t); if (status) { status = -EMSGSIZE; break; } if (t->delay_usecs) udelay(t->delay_usecs); } espi_trans->status = status; fsl_espi_setup_transfer(spi, NULL); } static void fsl_espi_cmd_trans(struct spi_message *m, struct fsl_espi_transfer *trans, u8 *rx_buff) { struct spi_transfer *t; u8 *local_buf; int i = 0; struct fsl_espi_transfer *espi_trans = trans; local_buf = kzalloc(SPCOM_TRANLEN_MAX, GFP_KERNEL); if (!local_buf) { espi_trans->status = -ENOMEM; return; } list_for_each_entry(t, &m->transfers, transfer_list) { if (t->tx_buf) { memcpy(local_buf + i, t->tx_buf, t->len); i += t->len; } } espi_trans->tx_buf = local_buf; espi_trans->rx_buf = local_buf + espi_trans->n_tx; fsl_espi_do_trans(m, espi_trans); espi_trans->actual_length = espi_trans->len; kfree(local_buf); } static void fsl_espi_rw_trans(struct spi_message *m, struct fsl_espi_transfer *trans, u8 *rx_buff) { struct fsl_espi_transfer *espi_trans = trans; unsigned int n_tx = espi_trans->n_tx; unsigned int n_rx = espi_trans->n_rx; struct spi_transfer *t; u8 *local_buf; u8 *rx_buf = rx_buff; unsigned int trans_len; unsigned int addr; int i, pos, loop; local_buf = kzalloc(SPCOM_TRANLEN_MAX, GFP_KERNEL); if (!local_buf) { espi_trans->status = -ENOMEM; return; } for (pos = 0, loop = 0; pos < n_rx; pos += trans_len, loop++) { trans_len = n_rx - pos; if (trans_len > SPCOM_TRANLEN_MAX - n_tx) trans_len = SPCOM_TRANLEN_MAX - n_tx; i = 0; list_for_each_entry(t, &m->transfers, transfer_list) { if (t->tx_buf) { memcpy(local_buf + i, t->tx_buf, t->len); i += t->len; } } if (pos > 0) { addr = fsl_espi_cmd2addr(local_buf); addr += pos; fsl_espi_addr2cmd(addr, local_buf); } espi_trans->n_tx = n_tx; espi_trans->n_rx = trans_len; espi_trans->len = trans_len + n_tx; espi_trans->tx_buf = local_buf; espi_trans->rx_buf = local_buf + n_tx; fsl_espi_do_trans(m, espi_trans); memcpy(rx_buf + pos, espi_trans->rx_buf + n_tx, trans_len); if (loop > 0) espi_trans->actual_length += espi_trans->len - n_tx; else espi_trans->actual_length += espi_trans->len; } kfree(local_buf); } static void fsl_espi_do_one_msg(struct spi_message *m) { struct spi_transfer *t; u8 *rx_buf = NULL; unsigned int n_tx = 0; unsigned int n_rx = 0; struct fsl_espi_transfer espi_trans; list_for_each_entry(t, &m->transfers, transfer_list) { if (t->tx_buf) n_tx += t->len; if (t->rx_buf) { n_rx += t->len; rx_buf = t->rx_buf; } } espi_trans.n_tx = n_tx; espi_trans.n_rx = n_rx; espi_trans.len = n_tx + n_rx; espi_trans.actual_length = 0; espi_trans.status = 0; if (!rx_buf) fsl_espi_cmd_trans(m, &espi_trans, NULL); else fsl_espi_rw_trans(m, &espi_trans, rx_buf); m->actual_length = espi_trans.actual_length; m->status = espi_trans.status; m->complete(m->context); } static int fsl_espi_setup(struct spi_device *spi) { struct mpc8xxx_spi *mpc8xxx_spi; struct fsl_espi_reg *reg_base; int retval; u32 hw_mode; u32 loop_mode; struct spi_mpc8xxx_cs *cs = spi->controller_state; if (!spi->max_speed_hz) return -EINVAL; if (!cs) { cs = kzalloc(sizeof *cs, GFP_KERNEL); if (!cs) return -ENOMEM; spi->controller_state = cs; } mpc8xxx_spi = spi_master_get_devdata(spi->master); reg_base = mpc8xxx_spi->reg_base; hw_mode = cs->hw_mode; /* Save original settings */ cs->hw_mode = mpc8xxx_spi_read_reg( ®_base->csmode[spi->chip_select]); /* mask out bits we are going to set */ cs->hw_mode &= ~(CSMODE_CP_BEGIN_EDGECLK | CSMODE_CI_INACTIVEHIGH | CSMODE_REV); if (spi->mode & SPI_CPHA) cs->hw_mode |= CSMODE_CP_BEGIN_EDGECLK; if (spi->mode & SPI_CPOL) cs->hw_mode |= CSMODE_CI_INACTIVEHIGH; if (!(spi->mode & SPI_LSB_FIRST)) cs->hw_mode |= CSMODE_REV; /* Handle the loop mode */ loop_mode = mpc8xxx_spi_read_reg(®_base->mode); loop_mode &= ~SPMODE_LOOP; if (spi->mode & SPI_LOOP) loop_mode |= SPMODE_LOOP; mpc8xxx_spi_write_reg(®_base->mode, loop_mode); retval = fsl_espi_setup_transfer(spi, NULL); if (retval < 0) { cs->hw_mode = hw_mode; /* Restore settings */ return retval; } return 0; } void fsl_espi_cpu_irq(struct mpc8xxx_spi *mspi, u32 events) { struct fsl_espi_reg *reg_base = mspi->reg_base; /* We need handle RX first */ if (events & SPIE_NE) { u32 rx_data, tmp; u8 rx_data_8; /* Spin until RX is done */ while (SPIE_RXCNT(events) < min(4, mspi->len)) { cpu_relax(); events = mpc8xxx_spi_read_reg(®_base->event); } if (mspi->len >= 4) { rx_data = mpc8xxx_spi_read_reg(®_base->receive); } else { tmp = mspi->len; rx_data = 0; while (tmp--) { rx_data_8 = in_8((u8 *)®_base->receive); rx_data |= (rx_data_8 << (tmp * 8)); } rx_data <<= (4 - mspi->len) * 8; } mspi->len -= 4; if (mspi->rx) mspi->get_rx(rx_data, mspi); } if (!(events & SPIE_NF)) { int ret; /* spin until TX is done */ ret = spin_event_timeout(((events = mpc8xxx_spi_read_reg( ®_base->event)) & SPIE_NF) == 0, 1000, 0); if (!ret) { dev_err(mspi->dev, "tired waiting for SPIE_NF\n"); return; } } /* Clear the events */ mpc8xxx_spi_write_reg(®_base->event, events); mspi->count -= 1; if (mspi->count) { u32 word = mspi->get_tx(mspi); mpc8xxx_spi_write_reg(®_base->transmit, word); } else { complete(&mspi->done); } } static irqreturn_t fsl_espi_irq(s32 irq, void *context_data) { struct mpc8xxx_spi *mspi = context_data; struct fsl_espi_reg *reg_base = mspi->reg_base; irqreturn_t ret = IRQ_NONE; u32 events; /* Get interrupt events(tx/rx) */ events = mpc8xxx_spi_read_reg(®_base->event); if (events) ret = IRQ_HANDLED; dev_vdbg(mspi->dev, "%s: events %x\n", __func__, events); fsl_espi_cpu_irq(mspi, events); return ret; } static void fsl_espi_remove(struct mpc8xxx_spi *mspi) { iounmap(mspi->reg_base); } static struct spi_master * fsl_espi_probe(struct device *dev, struct resource *mem, unsigned int irq) { struct fsl_spi_platform_data *pdata = dev->platform_data; struct spi_master *master; struct mpc8xxx_spi *mpc8xxx_spi; struct fsl_espi_reg *reg_base; u32 regval; int i, ret = 0; master = spi_alloc_master(dev, sizeof(struct mpc8xxx_spi)); if (!master) { ret = -ENOMEM; goto err; } dev_set_drvdata(dev, master); ret = mpc8xxx_spi_probe(dev, mem, irq); if (ret) goto err_probe; master->setup = fsl_espi_setup; mpc8xxx_spi = spi_master_get_devdata(master); mpc8xxx_spi->spi_do_one_msg = fsl_espi_do_one_msg; mpc8xxx_spi->spi_remove = fsl_espi_remove; mpc8xxx_spi->reg_base = ioremap(mem->start, resource_size(mem)); if (!mpc8xxx_spi->reg_base) { ret = -ENOMEM; goto err_probe; } reg_base = mpc8xxx_spi->reg_base; /* Register for SPI Interrupt */ ret = request_irq(mpc8xxx_spi->irq, fsl_espi_irq, 0, "fsl_espi", mpc8xxx_spi); if (ret) goto free_irq; if (mpc8xxx_spi->flags & SPI_QE_CPU_MODE) { mpc8xxx_spi->rx_shift = 16; mpc8xxx_spi->tx_shift = 24; } /* SPI controller initializations */ mpc8xxx_spi_write_reg(®_base->mode, 0); mpc8xxx_spi_write_reg(®_base->mask, 0); mpc8xxx_spi_write_reg(®_base->command, 0); mpc8xxx_spi_write_reg(®_base->event, 0xffffffff); /* Init eSPI CS mode register */ for (i = 0; i < pdata->max_chipselect; i++) mpc8xxx_spi_write_reg(®_base->csmode[i], CSMODE_INIT_VAL); /* Enable SPI interface */ regval = pdata->initial_spmode | SPMODE_INIT_VAL | SPMODE_ENABLE; mpc8xxx_spi_write_reg(®_base->mode, regval); ret = spi_register_master(master); if (ret < 0) goto unreg_master; dev_info(dev, "at 0x%p (irq = %d)\n", reg_base, mpc8xxx_spi->irq); return master; unreg_master: free_irq(mpc8xxx_spi->irq, mpc8xxx_spi); free_irq: iounmap(mpc8xxx_spi->reg_base); err_probe: spi_master_put(master); err: return ERR_PTR(ret); } static int of_fsl_espi_get_chipselects(struct device *dev) { struct device_node *np = dev->of_node; struct fsl_spi_platform_data *pdata = dev->platform_data; const u32 *prop; int len; prop = of_get_property(np, "fsl,espi-num-chipselects", &len); if (!prop || len < sizeof(*prop)) { dev_err(dev, "No 'fsl,espi-num-chipselects' property\n"); return -EINVAL; } pdata->max_chipselect = *prop; pdata->cs_control = NULL; return 0; } static int of_fsl_espi_probe(struct platform_device *ofdev) { struct device *dev = &ofdev->dev; struct device_node *np = ofdev->dev.of_node; struct spi_master *master; struct resource mem; struct resource irq; int ret = -ENOMEM; ret = of_mpc8xxx_spi_probe(ofdev); if (ret) return ret; ret = of_fsl_espi_get_chipselects(dev); if (ret) goto err; ret = of_address_to_resource(np, 0, &mem); if (ret) goto err; ret = of_irq_to_resource(np, 0, &irq); if (!ret) { ret = -EINVAL; goto err; } master = fsl_espi_probe(dev, &mem, irq.start); if (IS_ERR(master)) { ret = PTR_ERR(master); goto err; } return 0; err: return ret; } static int of_fsl_espi_remove(struct platform_device *dev) { return mpc8xxx_spi_remove(&dev->dev); } static const struct of_device_id of_fsl_espi_match[] = { { .compatible = "fsl,mpc8536-espi" }, {} }; MODULE_DEVICE_TABLE(of, of_fsl_espi_match); static struct platform_driver fsl_espi_driver = { .driver = { .name = "fsl_espi", .owner = THIS_MODULE, .of_match_table = of_fsl_espi_match, }, .probe = of_fsl_espi_probe, .remove = of_fsl_espi_remove, }; module_platform_driver(fsl_espi_driver); MODULE_AUTHOR("Mingkai Hu"); MODULE_DESCRIPTION("Enhanced Freescale SPI Driver"); MODULE_LICENSE("GPL");