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path: root/drivers/spi/spi-fsl-espi.c
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-rw-r--r--drivers/spi/spi-fsl-espi.c850
1 files changed, 850 insertions, 0 deletions
diff --git a/drivers/spi/spi-fsl-espi.c b/drivers/spi/spi-fsl-espi.c
new file mode 100644
index 000000000..b8dd75b85
--- /dev/null
+++ b/drivers/spi/spi-fsl-espi.c
@@ -0,0 +1,850 @@
+/*
+ * 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/delay.h>
+#include <linux/err.h>
+#include <linux/fsl_devices.h>
+#include <linux/interrupt.h>
+#include <linux/module.h>
+#include <linux/mm.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
+#include <linux/of_platform.h>
+#include <linux/platform_device.h>
+#include <linux/spi/spi.h>
+#include <linux/pm_runtime.h>
+#include <sysdev/fsl_soc.h>
+
+/* eSPI Controller registers */
+#define ESPI_SPMODE 0x00 /* eSPI mode register */
+#define ESPI_SPIE 0x04 /* eSPI event register */
+#define ESPI_SPIM 0x08 /* eSPI mask register */
+#define ESPI_SPCOM 0x0c /* eSPI command register */
+#define ESPI_SPITF 0x10 /* eSPI transmit FIFO access register*/
+#define ESPI_SPIRF 0x14 /* eSPI receive FIFO access register*/
+#define ESPI_SPMODE0 0x20 /* eSPI cs0 mode register */
+
+#define ESPI_SPMODEx(x) (ESPI_SPMODE0 + (x) * 4)
+
+/* eSPI Controller mode register definitions */
+#define SPMODE_ENABLE BIT(31)
+#define SPMODE_LOOP BIT(30)
+#define SPMODE_TXTHR(x) ((x) << 8)
+#define SPMODE_RXTHR(x) ((x) << 0)
+
+/* eSPI Controller CS mode register definitions */
+#define CSMODE_CI_INACTIVEHIGH BIT(31)
+#define CSMODE_CP_BEGIN_EDGECLK BIT(30)
+#define CSMODE_REV BIT(29)
+#define CSMODE_DIV16 BIT(28)
+#define CSMODE_PM(x) ((x) << 24)
+#define CSMODE_POL_1 BIT(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)
+
+#define FSL_ESPI_FIFO_SIZE 32
+#define FSL_ESPI_RXTHR 15
+
+/* Default mode/csmode for eSPI controller */
+#define SPMODE_INIT_VAL (SPMODE_TXTHR(4) | SPMODE_RXTHR(FSL_ESPI_RXTHR))
+#define CSMODE_INIT_VAL (CSMODE_POL_1 | CSMODE_BEF(0) \
+ | CSMODE_AFT(0) | CSMODE_CG(1))
+
+/* SPIE register values */
+#define SPIE_RXCNT(reg) ((reg >> 24) & 0x3F)
+#define SPIE_TXCNT(reg) ((reg >> 16) & 0x3F)
+#define SPIE_TXE BIT(15) /* TX FIFO empty */
+#define SPIE_DON BIT(14) /* TX done */
+#define SPIE_RXT BIT(13) /* RX FIFO threshold */
+#define SPIE_RXF BIT(12) /* RX FIFO full */
+#define SPIE_TXT BIT(11) /* TX FIFO threshold*/
+#define SPIE_RNE BIT(9) /* RX FIFO not empty */
+#define SPIE_TNF BIT(8) /* TX FIFO not full */
+
+/* SPIM register values */
+#define SPIM_TXE BIT(15) /* TX FIFO empty */
+#define SPIM_DON BIT(14) /* TX done */
+#define SPIM_RXT BIT(13) /* RX FIFO threshold */
+#define SPIM_RXF BIT(12) /* RX FIFO full */
+#define SPIM_TXT BIT(11) /* TX FIFO threshold*/
+#define SPIM_RNE BIT(9) /* RX FIFO not empty */
+#define SPIM_TNF BIT(8) /* TX FIFO not full */
+
+/* SPCOM register values */
+#define SPCOM_CS(x) ((x) << 30)
+#define SPCOM_DO BIT(28) /* Dual output */
+#define SPCOM_TO BIT(27) /* TX only */
+#define SPCOM_RXSKIP(x) ((x) << 16)
+#define SPCOM_TRANLEN(x) ((x) << 0)
+
+#define SPCOM_TRANLEN_MAX 0x10000 /* Max transaction length */
+
+#define AUTOSUSPEND_TIMEOUT 2000
+
+struct fsl_espi {
+ struct device *dev;
+ void __iomem *reg_base;
+
+ struct list_head *m_transfers;
+ struct spi_transfer *tx_t;
+ unsigned int tx_pos;
+ bool tx_done;
+ struct spi_transfer *rx_t;
+ unsigned int rx_pos;
+ bool rx_done;
+
+ bool swab;
+ unsigned int rxskip;
+
+ spinlock_t lock;
+
+ u32 spibrg; /* SPIBRG input clock */
+
+ struct completion done;
+};
+
+struct fsl_espi_cs {
+ u32 hw_mode;
+};
+
+static inline u32 fsl_espi_read_reg(struct fsl_espi *espi, int offset)
+{
+ return ioread32be(espi->reg_base + offset);
+}
+
+static inline u16 fsl_espi_read_reg16(struct fsl_espi *espi, int offset)
+{
+ return ioread16be(espi->reg_base + offset);
+}
+
+static inline u8 fsl_espi_read_reg8(struct fsl_espi *espi, int offset)
+{
+ return ioread8(espi->reg_base + offset);
+}
+
+static inline void fsl_espi_write_reg(struct fsl_espi *espi, int offset,
+ u32 val)
+{
+ iowrite32be(val, espi->reg_base + offset);
+}
+
+static inline void fsl_espi_write_reg16(struct fsl_espi *espi, int offset,
+ u16 val)
+{
+ iowrite16be(val, espi->reg_base + offset);
+}
+
+static inline void fsl_espi_write_reg8(struct fsl_espi *espi, int offset,
+ u8 val)
+{
+ iowrite8(val, espi->reg_base + offset);
+}
+
+static int fsl_espi_check_message(struct spi_message *m)
+{
+ struct fsl_espi *espi = spi_master_get_devdata(m->spi->master);
+ struct spi_transfer *t, *first;
+
+ if (m->frame_length > SPCOM_TRANLEN_MAX) {
+ dev_err(espi->dev, "message too long, size is %u bytes\n",
+ m->frame_length);
+ return -EMSGSIZE;
+ }
+
+ 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) {
+ dev_err(espi->dev, "bits_per_word/speed_hz should be the same for all transfers\n");
+ return -EINVAL;
+ }
+ }
+
+ /* ESPI supports MSB-first transfers for word size 8 / 16 only */
+ if (!(m->spi->mode & SPI_LSB_FIRST) && first->bits_per_word != 8 &&
+ first->bits_per_word != 16) {
+ dev_err(espi->dev,
+ "MSB-first transfer not supported for wordsize %u\n",
+ first->bits_per_word);
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+static unsigned int fsl_espi_check_rxskip_mode(struct spi_message *m)
+{
+ struct spi_transfer *t;
+ unsigned int i = 0, rxskip = 0;
+
+ /*
+ * prerequisites for ESPI rxskip mode:
+ * - message has two transfers
+ * - first transfer is a write and second is a read
+ *
+ * In addition the current low-level transfer mechanism requires
+ * that the rxskip bytes fit into the TX FIFO. Else the transfer
+ * would hang because after the first FSL_ESPI_FIFO_SIZE bytes
+ * the TX FIFO isn't re-filled.
+ */
+ list_for_each_entry(t, &m->transfers, transfer_list) {
+ if (i == 0) {
+ if (!t->tx_buf || t->rx_buf ||
+ t->len > FSL_ESPI_FIFO_SIZE)
+ return 0;
+ rxskip = t->len;
+ } else if (i == 1) {
+ if (t->tx_buf || !t->rx_buf)
+ return 0;
+ }
+ i++;
+ }
+
+ return i == 2 ? rxskip : 0;
+}
+
+static void fsl_espi_fill_tx_fifo(struct fsl_espi *espi, u32 events)
+{
+ u32 tx_fifo_avail;
+ unsigned int tx_left;
+ const void *tx_buf;
+
+ /* if events is zero transfer has not started and tx fifo is empty */
+ tx_fifo_avail = events ? SPIE_TXCNT(events) : FSL_ESPI_FIFO_SIZE;
+start:
+ tx_left = espi->tx_t->len - espi->tx_pos;
+ tx_buf = espi->tx_t->tx_buf;
+ while (tx_fifo_avail >= min(4U, tx_left) && tx_left) {
+ if (tx_left >= 4) {
+ if (!tx_buf)
+ fsl_espi_write_reg(espi, ESPI_SPITF, 0);
+ else if (espi->swab)
+ fsl_espi_write_reg(espi, ESPI_SPITF,
+ swahb32p(tx_buf + espi->tx_pos));
+ else
+ fsl_espi_write_reg(espi, ESPI_SPITF,
+ *(u32 *)(tx_buf + espi->tx_pos));
+ espi->tx_pos += 4;
+ tx_left -= 4;
+ tx_fifo_avail -= 4;
+ } else if (tx_left >= 2 && tx_buf && espi->swab) {
+ fsl_espi_write_reg16(espi, ESPI_SPITF,
+ swab16p(tx_buf + espi->tx_pos));
+ espi->tx_pos += 2;
+ tx_left -= 2;
+ tx_fifo_avail -= 2;
+ } else {
+ if (!tx_buf)
+ fsl_espi_write_reg8(espi, ESPI_SPITF, 0);
+ else
+ fsl_espi_write_reg8(espi, ESPI_SPITF,
+ *(u8 *)(tx_buf + espi->tx_pos));
+ espi->tx_pos += 1;
+ tx_left -= 1;
+ tx_fifo_avail -= 1;
+ }
+ }
+
+ if (!tx_left) {
+ /* Last transfer finished, in rxskip mode only one is needed */
+ if (list_is_last(&espi->tx_t->transfer_list,
+ espi->m_transfers) || espi->rxskip) {
+ espi->tx_done = true;
+ return;
+ }
+ espi->tx_t = list_next_entry(espi->tx_t, transfer_list);
+ espi->tx_pos = 0;
+ /* continue with next transfer if tx fifo is not full */
+ if (tx_fifo_avail)
+ goto start;
+ }
+}
+
+static void fsl_espi_read_rx_fifo(struct fsl_espi *espi, u32 events)
+{
+ u32 rx_fifo_avail = SPIE_RXCNT(events);
+ unsigned int rx_left;
+ void *rx_buf;
+
+start:
+ rx_left = espi->rx_t->len - espi->rx_pos;
+ rx_buf = espi->rx_t->rx_buf;
+ while (rx_fifo_avail >= min(4U, rx_left) && rx_left) {
+ if (rx_left >= 4) {
+ u32 val = fsl_espi_read_reg(espi, ESPI_SPIRF);
+
+ if (rx_buf && espi->swab)
+ *(u32 *)(rx_buf + espi->rx_pos) = swahb32(val);
+ else if (rx_buf)
+ *(u32 *)(rx_buf + espi->rx_pos) = val;
+ espi->rx_pos += 4;
+ rx_left -= 4;
+ rx_fifo_avail -= 4;
+ } else if (rx_left >= 2 && rx_buf && espi->swab) {
+ u16 val = fsl_espi_read_reg16(espi, ESPI_SPIRF);
+
+ *(u16 *)(rx_buf + espi->rx_pos) = swab16(val);
+ espi->rx_pos += 2;
+ rx_left -= 2;
+ rx_fifo_avail -= 2;
+ } else {
+ u8 val = fsl_espi_read_reg8(espi, ESPI_SPIRF);
+
+ if (rx_buf)
+ *(u8 *)(rx_buf + espi->rx_pos) = val;
+ espi->rx_pos += 1;
+ rx_left -= 1;
+ rx_fifo_avail -= 1;
+ }
+ }
+
+ if (!rx_left) {
+ if (list_is_last(&espi->rx_t->transfer_list,
+ espi->m_transfers)) {
+ espi->rx_done = true;
+ return;
+ }
+ espi->rx_t = list_next_entry(espi->rx_t, transfer_list);
+ espi->rx_pos = 0;
+ /* continue with next transfer if rx fifo is not empty */
+ if (rx_fifo_avail)
+ goto start;
+ }
+}
+
+static void fsl_espi_setup_transfer(struct spi_device *spi,
+ struct spi_transfer *t)
+{
+ struct fsl_espi *espi = spi_master_get_devdata(spi->master);
+ int bits_per_word = t ? t->bits_per_word : spi->bits_per_word;
+ u32 pm, hz = t ? t->speed_hz : spi->max_speed_hz;
+ struct fsl_espi_cs *cs = spi_get_ctldata(spi);
+ u32 hw_mode_old = cs->hw_mode;
+
+ /* 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 - 1);
+
+ pm = DIV_ROUND_UP(espi->spibrg, hz * 4) - 1;
+
+ if (pm > 15) {
+ cs->hw_mode |= CSMODE_DIV16;
+ pm = DIV_ROUND_UP(espi->spibrg, hz * 16 * 4) - 1;
+ }
+
+ cs->hw_mode |= CSMODE_PM(pm);
+
+ /* don't write the mode register if the mode doesn't change */
+ if (cs->hw_mode != hw_mode_old)
+ fsl_espi_write_reg(espi, ESPI_SPMODEx(spi->chip_select),
+ cs->hw_mode);
+}
+
+static int fsl_espi_bufs(struct spi_device *spi, struct spi_transfer *t)
+{
+ struct fsl_espi *espi = spi_master_get_devdata(spi->master);
+ unsigned int rx_len = t->len;
+ u32 mask, spcom;
+ int ret;
+
+ reinit_completion(&espi->done);
+
+ /* Set SPCOM[CS] and SPCOM[TRANLEN] field */
+ spcom = SPCOM_CS(spi->chip_select);
+ spcom |= SPCOM_TRANLEN(t->len - 1);
+
+ /* configure RXSKIP mode */
+ if (espi->rxskip) {
+ spcom |= SPCOM_RXSKIP(espi->rxskip);
+ rx_len = t->len - espi->rxskip;
+ if (t->rx_nbits == SPI_NBITS_DUAL)
+ spcom |= SPCOM_DO;
+ }
+
+ fsl_espi_write_reg(espi, ESPI_SPCOM, spcom);
+
+ /* enable interrupts */
+ mask = SPIM_DON;
+ if (rx_len > FSL_ESPI_FIFO_SIZE)
+ mask |= SPIM_RXT;
+ fsl_espi_write_reg(espi, ESPI_SPIM, mask);
+
+ /* Prevent filling the fifo from getting interrupted */
+ spin_lock_irq(&espi->lock);
+ fsl_espi_fill_tx_fifo(espi, 0);
+ spin_unlock_irq(&espi->lock);
+
+ /* Won't hang up forever, SPI bus sometimes got lost interrupts... */
+ ret = wait_for_completion_timeout(&espi->done, 2 * HZ);
+ if (ret == 0)
+ dev_err(espi->dev, "Transfer timed out!\n");
+
+ /* disable rx ints */
+ fsl_espi_write_reg(espi, ESPI_SPIM, 0);
+
+ return ret == 0 ? -ETIMEDOUT : 0;
+}
+
+static int fsl_espi_trans(struct spi_message *m, struct spi_transfer *trans)
+{
+ struct fsl_espi *espi = spi_master_get_devdata(m->spi->master);
+ struct spi_device *spi = m->spi;
+ int ret;
+
+ /* In case of LSB-first and bits_per_word > 8 byte-swap all words */
+ espi->swab = spi->mode & SPI_LSB_FIRST && trans->bits_per_word > 8;
+
+ espi->m_transfers = &m->transfers;
+ espi->tx_t = list_first_entry(&m->transfers, struct spi_transfer,
+ transfer_list);
+ espi->tx_pos = 0;
+ espi->tx_done = false;
+ espi->rx_t = list_first_entry(&m->transfers, struct spi_transfer,
+ transfer_list);
+ espi->rx_pos = 0;
+ espi->rx_done = false;
+
+ espi->rxskip = fsl_espi_check_rxskip_mode(m);
+ if (trans->rx_nbits == SPI_NBITS_DUAL && !espi->rxskip) {
+ dev_err(espi->dev, "Dual output mode requires RXSKIP mode!\n");
+ return -EINVAL;
+ }
+
+ /* In RXSKIP mode skip first transfer for reads */
+ if (espi->rxskip)
+ espi->rx_t = list_next_entry(espi->rx_t, transfer_list);
+
+ fsl_espi_setup_transfer(spi, trans);
+
+ ret = fsl_espi_bufs(spi, trans);
+
+ if (trans->delay_usecs)
+ udelay(trans->delay_usecs);
+
+ return ret;
+}
+
+static int fsl_espi_do_one_msg(struct spi_master *master,
+ struct spi_message *m)
+{
+ unsigned int delay_usecs = 0, rx_nbits = 0;
+ struct spi_transfer *t, trans = {};
+ int ret;
+
+ ret = fsl_espi_check_message(m);
+ if (ret)
+ goto out;
+
+ list_for_each_entry(t, &m->transfers, transfer_list) {
+ if (t->delay_usecs > delay_usecs)
+ delay_usecs = t->delay_usecs;
+ if (t->rx_nbits > rx_nbits)
+ rx_nbits = t->rx_nbits;
+ }
+
+ t = list_first_entry(&m->transfers, struct spi_transfer,
+ transfer_list);
+
+ trans.len = m->frame_length;
+ trans.speed_hz = t->speed_hz;
+ trans.bits_per_word = t->bits_per_word;
+ trans.delay_usecs = delay_usecs;
+ trans.rx_nbits = rx_nbits;
+
+ if (trans.len)
+ ret = fsl_espi_trans(m, &trans);
+
+ m->actual_length = ret ? 0 : trans.len;
+out:
+ if (m->status == -EINPROGRESS)
+ m->status = ret;
+
+ spi_finalize_current_message(master);
+
+ return ret;
+}
+
+static int fsl_espi_setup(struct spi_device *spi)
+{
+ struct fsl_espi *espi;
+ u32 loop_mode;
+ struct fsl_espi_cs *cs = spi_get_ctldata(spi);
+
+ if (!cs) {
+ cs = kzalloc(sizeof(*cs), GFP_KERNEL);
+ if (!cs)
+ return -ENOMEM;
+ spi_set_ctldata(spi, cs);
+ }
+
+ espi = spi_master_get_devdata(spi->master);
+
+ pm_runtime_get_sync(espi->dev);
+
+ cs->hw_mode = fsl_espi_read_reg(espi, ESPI_SPMODEx(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 = fsl_espi_read_reg(espi, ESPI_SPMODE);
+ loop_mode &= ~SPMODE_LOOP;
+ if (spi->mode & SPI_LOOP)
+ loop_mode |= SPMODE_LOOP;
+ fsl_espi_write_reg(espi, ESPI_SPMODE, loop_mode);
+
+ fsl_espi_setup_transfer(spi, NULL);
+
+ pm_runtime_mark_last_busy(espi->dev);
+ pm_runtime_put_autosuspend(espi->dev);
+
+ return 0;
+}
+
+static void fsl_espi_cleanup(struct spi_device *spi)
+{
+ struct fsl_espi_cs *cs = spi_get_ctldata(spi);
+
+ kfree(cs);
+ spi_set_ctldata(spi, NULL);
+}
+
+static void fsl_espi_cpu_irq(struct fsl_espi *espi, u32 events)
+{
+ if (!espi->rx_done)
+ fsl_espi_read_rx_fifo(espi, events);
+
+ if (!espi->tx_done)
+ fsl_espi_fill_tx_fifo(espi, events);
+
+ if (!espi->tx_done || !espi->rx_done)
+ return;
+
+ /* we're done, but check for errors before returning */
+ events = fsl_espi_read_reg(espi, ESPI_SPIE);
+
+ if (!(events & SPIE_DON))
+ dev_err(espi->dev,
+ "Transfer done but SPIE_DON isn't set!\n");
+
+ if (SPIE_RXCNT(events) || SPIE_TXCNT(events) != FSL_ESPI_FIFO_SIZE) {
+ dev_err(espi->dev, "Transfer done but rx/tx fifo's aren't empty!\n");
+ dev_err(espi->dev, "SPIE_RXCNT = %d, SPIE_TXCNT = %d\n",
+ SPIE_RXCNT(events), SPIE_TXCNT(events));
+ }
+
+ complete(&espi->done);
+}
+
+static irqreturn_t fsl_espi_irq(s32 irq, void *context_data)
+{
+ struct fsl_espi *espi = context_data;
+ u32 events, mask;
+
+ spin_lock(&espi->lock);
+
+ /* Get interrupt events(tx/rx) */
+ events = fsl_espi_read_reg(espi, ESPI_SPIE);
+ mask = fsl_espi_read_reg(espi, ESPI_SPIM);
+ if (!(events & mask)) {
+ spin_unlock(&espi->lock);
+ return IRQ_NONE;
+ }
+
+ dev_vdbg(espi->dev, "%s: events %x\n", __func__, events);
+
+ fsl_espi_cpu_irq(espi, events);
+
+ /* Clear the events */
+ fsl_espi_write_reg(espi, ESPI_SPIE, events);
+
+ spin_unlock(&espi->lock);
+
+ return IRQ_HANDLED;
+}
+
+#ifdef CONFIG_PM
+static int fsl_espi_runtime_suspend(struct device *dev)
+{
+ struct spi_master *master = dev_get_drvdata(dev);
+ struct fsl_espi *espi = spi_master_get_devdata(master);
+ u32 regval;
+
+ regval = fsl_espi_read_reg(espi, ESPI_SPMODE);
+ regval &= ~SPMODE_ENABLE;
+ fsl_espi_write_reg(espi, ESPI_SPMODE, regval);
+
+ return 0;
+}
+
+static int fsl_espi_runtime_resume(struct device *dev)
+{
+ struct spi_master *master = dev_get_drvdata(dev);
+ struct fsl_espi *espi = spi_master_get_devdata(master);
+ u32 regval;
+
+ regval = fsl_espi_read_reg(espi, ESPI_SPMODE);
+ regval |= SPMODE_ENABLE;
+ fsl_espi_write_reg(espi, ESPI_SPMODE, regval);
+
+ return 0;
+}
+#endif
+
+static size_t fsl_espi_max_message_size(struct spi_device *spi)
+{
+ return SPCOM_TRANLEN_MAX;
+}
+
+static void fsl_espi_init_regs(struct device *dev, bool initial)
+{
+ struct spi_master *master = dev_get_drvdata(dev);
+ struct fsl_espi *espi = spi_master_get_devdata(master);
+ struct device_node *nc;
+ u32 csmode, cs, prop;
+ int ret;
+
+ /* SPI controller initializations */
+ fsl_espi_write_reg(espi, ESPI_SPMODE, 0);
+ fsl_espi_write_reg(espi, ESPI_SPIM, 0);
+ fsl_espi_write_reg(espi, ESPI_SPCOM, 0);
+ fsl_espi_write_reg(espi, ESPI_SPIE, 0xffffffff);
+
+ /* Init eSPI CS mode register */
+ for_each_available_child_of_node(master->dev.of_node, nc) {
+ /* get chip select */
+ ret = of_property_read_u32(nc, "reg", &cs);
+ if (ret || cs >= master->num_chipselect)
+ continue;
+
+ csmode = CSMODE_INIT_VAL;
+
+ /* check if CSBEF is set in device tree */
+ ret = of_property_read_u32(nc, "fsl,csbef", &prop);
+ if (!ret) {
+ csmode &= ~(CSMODE_BEF(0xf));
+ csmode |= CSMODE_BEF(prop);
+ }
+
+ /* check if CSAFT is set in device tree */
+ ret = of_property_read_u32(nc, "fsl,csaft", &prop);
+ if (!ret) {
+ csmode &= ~(CSMODE_AFT(0xf));
+ csmode |= CSMODE_AFT(prop);
+ }
+
+ fsl_espi_write_reg(espi, ESPI_SPMODEx(cs), csmode);
+
+ if (initial)
+ dev_info(dev, "cs=%u, init_csmode=0x%x\n", cs, csmode);
+ }
+
+ /* Enable SPI interface */
+ fsl_espi_write_reg(espi, ESPI_SPMODE, SPMODE_INIT_VAL | SPMODE_ENABLE);
+}
+
+static int fsl_espi_probe(struct device *dev, struct resource *mem,
+ unsigned int irq, unsigned int num_cs)
+{
+ struct spi_master *master;
+ struct fsl_espi *espi;
+ int ret;
+
+ master = spi_alloc_master(dev, sizeof(struct fsl_espi));
+ if (!master)
+ return -ENOMEM;
+
+ dev_set_drvdata(dev, master);
+
+ master->mode_bits = SPI_RX_DUAL | SPI_CPOL | SPI_CPHA | SPI_CS_HIGH |
+ SPI_LSB_FIRST | SPI_LOOP;
+ master->dev.of_node = dev->of_node;
+ master->bits_per_word_mask = SPI_BPW_RANGE_MASK(4, 16);
+ master->setup = fsl_espi_setup;
+ master->cleanup = fsl_espi_cleanup;
+ master->transfer_one_message = fsl_espi_do_one_msg;
+ master->auto_runtime_pm = true;
+ master->max_message_size = fsl_espi_max_message_size;
+ master->num_chipselect = num_cs;
+
+ espi = spi_master_get_devdata(master);
+ spin_lock_init(&espi->lock);
+
+ espi->dev = dev;
+ espi->spibrg = fsl_get_sys_freq();
+ if (espi->spibrg == -1) {
+ dev_err(dev, "Can't get sys frequency!\n");
+ ret = -EINVAL;
+ goto err_probe;
+ }
+ /* determined by clock divider fields DIV16/PM in register SPMODEx */
+ master->min_speed_hz = DIV_ROUND_UP(espi->spibrg, 4 * 16 * 16);
+ master->max_speed_hz = DIV_ROUND_UP(espi->spibrg, 4);
+
+ init_completion(&espi->done);
+
+ espi->reg_base = devm_ioremap_resource(dev, mem);
+ if (IS_ERR(espi->reg_base)) {
+ ret = PTR_ERR(espi->reg_base);
+ goto err_probe;
+ }
+
+ /* Register for SPI Interrupt */
+ ret = devm_request_irq(dev, irq, fsl_espi_irq, 0, "fsl_espi", espi);
+ if (ret)
+ goto err_probe;
+
+ fsl_espi_init_regs(dev, true);
+
+ pm_runtime_set_autosuspend_delay(dev, AUTOSUSPEND_TIMEOUT);
+ pm_runtime_use_autosuspend(dev);
+ pm_runtime_set_active(dev);
+ pm_runtime_enable(dev);
+ pm_runtime_get_sync(dev);
+
+ ret = devm_spi_register_master(dev, master);
+ if (ret < 0)
+ goto err_pm;
+
+ dev_info(dev, "at 0x%p (irq = %u)\n", espi->reg_base, irq);
+
+ pm_runtime_mark_last_busy(dev);
+ pm_runtime_put_autosuspend(dev);
+
+ return 0;
+
+err_pm:
+ pm_runtime_put_noidle(dev);
+ pm_runtime_disable(dev);
+ pm_runtime_set_suspended(dev);
+err_probe:
+ spi_master_put(master);
+ return ret;
+}
+
+static int of_fsl_espi_get_chipselects(struct device *dev)
+{
+ struct device_node *np = dev->of_node;
+ u32 num_cs;
+ int ret;
+
+ ret = of_property_read_u32(np, "fsl,espi-num-chipselects", &num_cs);
+ if (ret) {
+ dev_err(dev, "No 'fsl,espi-num-chipselects' property\n");
+ return 0;
+ }
+
+ return num_cs;
+}
+
+static int of_fsl_espi_probe(struct platform_device *ofdev)
+{
+ struct device *dev = &ofdev->dev;
+ struct device_node *np = ofdev->dev.of_node;
+ struct resource mem;
+ unsigned int irq, num_cs;
+ int ret;
+
+ if (of_property_read_bool(np, "mode")) {
+ dev_err(dev, "mode property is not supported on ESPI!\n");
+ return -EINVAL;
+ }
+
+ num_cs = of_fsl_espi_get_chipselects(dev);
+ if (!num_cs)
+ return -EINVAL;
+
+ ret = of_address_to_resource(np, 0, &mem);
+ if (ret)
+ return ret;
+
+ irq = irq_of_parse_and_map(np, 0);
+ if (!irq)
+ return -EINVAL;
+
+ return fsl_espi_probe(dev, &mem, irq, num_cs);
+}
+
+static int of_fsl_espi_remove(struct platform_device *dev)
+{
+ pm_runtime_disable(&dev->dev);
+
+ return 0;
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int of_fsl_espi_suspend(struct device *dev)
+{
+ struct spi_master *master = dev_get_drvdata(dev);
+ int ret;
+
+ ret = spi_master_suspend(master);
+ if (ret) {
+ dev_warn(dev, "cannot suspend master\n");
+ return ret;
+ }
+
+ return pm_runtime_force_suspend(dev);
+}
+
+static int of_fsl_espi_resume(struct device *dev)
+{
+ struct spi_master *master = dev_get_drvdata(dev);
+ int ret;
+
+ fsl_espi_init_regs(dev, false);
+
+ ret = pm_runtime_force_resume(dev);
+ if (ret < 0)
+ return ret;
+
+ return spi_master_resume(master);
+}
+#endif /* CONFIG_PM_SLEEP */
+
+static const struct dev_pm_ops espi_pm = {
+ SET_RUNTIME_PM_OPS(fsl_espi_runtime_suspend,
+ fsl_espi_runtime_resume, NULL)
+ SET_SYSTEM_SLEEP_PM_OPS(of_fsl_espi_suspend, of_fsl_espi_resume)
+};
+
+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",
+ .of_match_table = of_fsl_espi_match,
+ .pm = &espi_pm,
+ },
+ .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");
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-12 02:40:05 +0000