* (C) Copyright 2012 SAMSUNG Electronics
* Padmavathi Venna <padma.v@samsung.com>
*
- * 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.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ * SPDX-License-Identifier: GPL-2.0+
*/
#include <common.h>
+#include <dm.h>
+#include <errno.h>
#include <malloc.h>
#include <spi.h>
+#include <fdtdec.h>
#include <asm/arch/clk.h>
#include <asm/arch/clock.h>
#include <asm/arch/cpu.h>
#include <asm/arch-exynos/spi.h>
#include <asm/io.h>
-/* Information about each SPI controller */
-struct spi_bus {
+DECLARE_GLOBAL_DATA_PTR;
+
+struct exynos_spi_platdata {
enum periph_id periph_id;
s32 frequency; /* Default clock frequency, -1 for none */
struct exynos_spi *regs;
- int inited; /* 1 if this bus is ready for use */
+ uint deactivate_delay_us; /* Delay to wait after deactivate */
};
-/* A list of spi buses that we know about */
-static struct spi_bus spi_bus[EXYNOS5_SPI_NUM_CONTROLLERS];
-
-struct exynos_spi_slave {
- struct spi_slave slave;
+struct exynos_spi_priv {
struct exynos_spi *regs;
unsigned int freq; /* Default frequency */
unsigned int mode;
enum periph_id periph_id; /* Peripheral ID for this device */
unsigned int fifo_size;
+ int skip_preamble;
+ ulong last_transaction_us; /* Time of last transaction end */
};
-static struct spi_bus *spi_get_bus(unsigned dev_index)
-{
- if (dev_index < EXYNOS5_SPI_NUM_CONTROLLERS)
- return &spi_bus[dev_index];
- debug("%s: invalid bus %d", __func__, dev_index);
-
- return NULL;
-}
-
-static inline struct exynos_spi_slave *to_exynos_spi(struct spi_slave *slave)
-{
- return container_of(slave, struct exynos_spi_slave, slave);
-}
-
-/**
- * Setup the driver private data
- *
- * @param bus ID of the bus that the slave is attached to
- * @param cs ID of the chip select connected to the slave
- * @param max_hz Required spi frequency
- * @param mode Required spi mode (clk polarity, clk phase and
- * master or slave)
- * @return new device or NULL
- */
-struct spi_slave *spi_setup_slave(unsigned int busnum, unsigned int cs,
- unsigned int max_hz, unsigned int mode)
-{
- struct exynos_spi_slave *spi_slave;
- struct spi_bus *bus;
-
- if (!spi_cs_is_valid(busnum, cs)) {
- debug("%s: Invalid bus/chip select %d, %d\n", __func__,
- busnum, cs);
- return NULL;
- }
-
- spi_slave = malloc(sizeof(*spi_slave));
- if (!spi_slave) {
- debug("%s: Could not allocate spi_slave\n", __func__);
- return NULL;
- }
-
- bus = &spi_bus[busnum];
- spi_slave->slave.bus = busnum;
- spi_slave->slave.cs = cs;
- spi_slave->regs = bus->regs;
- spi_slave->mode = mode;
- spi_slave->periph_id = bus->periph_id;
- if (bus->periph_id == PERIPH_ID_SPI1 ||
- bus->periph_id == PERIPH_ID_SPI2)
- spi_slave->fifo_size = 64;
- else
- spi_slave->fifo_size = 256;
-
- spi_slave->freq = bus->frequency;
- if (max_hz)
- spi_slave->freq = min(max_hz, spi_slave->freq);
-
- return &spi_slave->slave;
-}
-
-/**
- * Free spi controller
- *
- * @param slave Pointer to spi_slave to which controller has to
- * communicate with
- */
-void spi_free_slave(struct spi_slave *slave)
-{
- struct exynos_spi_slave *spi_slave = to_exynos_spi(slave);
-
- free(spi_slave);
-}
-
/**
* Flush spi tx, rx fifos and reset the SPI controller
*
- * @param slave Pointer to spi_slave to which controller has to
- * communicate with
+ * @param regs Pointer to SPI registers
*/
-static void spi_flush_fifo(struct spi_slave *slave)
+static void spi_flush_fifo(struct exynos_spi *regs)
{
- struct exynos_spi_slave *spi_slave = to_exynos_spi(slave);
- struct exynos_spi *regs = spi_slave->regs;
-
clrsetbits_le32(®s->ch_cfg, SPI_CH_HS_EN, SPI_CH_RST);
clrbits_le32(®s->ch_cfg, SPI_CH_RST);
setbits_le32(®s->ch_cfg, SPI_TX_CH_ON | SPI_RX_CH_ON);
}
-/**
- * Initialize the spi base registers, set the required clock frequency and
- * initialize the gpios
- *
- * @param slave Pointer to spi_slave to which controller has to
- * communicate with
- * @return zero on success else a negative value
- */
-int spi_claim_bus(struct spi_slave *slave)
-{
- struct exynos_spi_slave *spi_slave = to_exynos_spi(slave);
- struct exynos_spi *regs = spi_slave->regs;
- u32 reg = 0;
- int ret;
-
- ret = set_spi_clk(spi_slave->periph_id,
- spi_slave->freq);
- if (ret < 0) {
- debug("%s: Failed to setup spi clock\n", __func__);
- return ret;
- }
-
- exynos_pinmux_config(spi_slave->periph_id, PINMUX_FLAG_NONE);
-
- spi_flush_fifo(slave);
-
- reg = readl(®s->ch_cfg);
- reg &= ~(SPI_CH_CPHA_B | SPI_CH_CPOL_L);
-
- if (spi_slave->mode & SPI_CPHA)
- reg |= SPI_CH_CPHA_B;
-
- if (spi_slave->mode & SPI_CPOL)
- reg |= SPI_CH_CPOL_L;
-
- writel(reg, ®s->ch_cfg);
- writel(SPI_FB_DELAY_180, ®s->fb_clk);
-
- return 0;
-}
-
-/**
- * Reset the spi H/W and flush the tx and rx fifos
- *
- * @param slave Pointer to spi_slave to which controller has to
- * communicate with
- */
-void spi_release_bus(struct spi_slave *slave)
-{
- spi_flush_fifo(slave);
-}
-
static void spi_get_fifo_levels(struct exynos_spi *regs,
int *rx_lvl, int *tx_lvl)
{
*
* @param regs SPI peripheral registers
* @param count Number of bytes to transfer
+ * @param step Number of bytes to transfer in each packet (1 or 4)
*/
-static void spi_request_bytes(struct exynos_spi *regs, int count)
+static void spi_request_bytes(struct exynos_spi *regs, int count, int step)
{
+ debug("%s: regs=%p, count=%d, step=%d\n", __func__, regs, count, step);
+
+ /* For word address we need to swap bytes */
+ if (step == 4) {
+ setbits_le32(®s->mode_cfg,
+ SPI_MODE_CH_WIDTH_WORD | SPI_MODE_BUS_WIDTH_WORD);
+ count /= 4;
+ setbits_le32(®s->swap_cfg, SPI_TX_SWAP_EN | SPI_RX_SWAP_EN |
+ SPI_TX_BYTE_SWAP | SPI_RX_BYTE_SWAP |
+ SPI_TX_HWORD_SWAP | SPI_RX_HWORD_SWAP);
+ } else {
+ /* Select byte access and clear the swap configuration */
+ clrbits_le32(®s->mode_cfg,
+ SPI_MODE_CH_WIDTH_WORD | SPI_MODE_BUS_WIDTH_WORD);
+ writel(0, ®s->swap_cfg);
+ }
+
assert(count && count < (1 << 16));
setbits_le32(®s->ch_cfg, SPI_CH_RST);
clrbits_le32(®s->ch_cfg, SPI_CH_RST);
+
writel(count | SPI_PACKET_CNT_EN, ®s->pkt_cnt);
}
-static void spi_rx_tx(struct exynos_spi_slave *spi_slave, int todo,
- void **dinp, void const **doutp)
+static int spi_rx_tx(struct exynos_spi_priv *priv, int todo,
+ void **dinp, void const **doutp, unsigned long flags)
{
- struct exynos_spi *regs = spi_slave->regs;
+ struct exynos_spi *regs = priv->regs;
uchar *rxp = *dinp;
const uchar *txp = *doutp;
int rx_lvl, tx_lvl;
uint out_bytes, in_bytes;
+ int toread;
+ unsigned start = get_timer(0);
+ int stopping;
+ int step;
out_bytes = in_bytes = todo;
+ stopping = priv->skip_preamble && (flags & SPI_XFER_END) &&
+ !(priv->mode & SPI_SLAVE);
+
+ /*
+ * Try to transfer words if we can. This helps read performance at
+ * SPI clock speeds above about 20MHz.
+ */
+ step = 1;
+ if (!((todo | (uintptr_t)rxp | (uintptr_t)txp) & 3) &&
+ !priv->skip_preamble)
+ step = 4;
+
/*
* If there's something to send, do a software reset and set a
* transaction size.
*/
- spi_request_bytes(regs, todo);
+ spi_request_bytes(regs, todo, step);
/*
* Bytes are transmitted/received in pairs. Wait to receive all the
* data because then transmission will be done as well.
*/
+ toread = in_bytes;
+
while (in_bytes) {
int temp;
/* Keep the fifos full/empty. */
spi_get_fifo_levels(regs, &rx_lvl, &tx_lvl);
- if (tx_lvl < spi_slave->fifo_size && out_bytes) {
- temp = txp ? *txp++ : 0xff;
+
+ /*
+ * Don't completely fill the txfifo, since we don't want our
+ * rxfifo to overflow, and it may already contain data.
+ */
+ while (tx_lvl < priv->fifo_size/2 && out_bytes) {
+ if (!txp)
+ temp = -1;
+ else if (step == 4)
+ temp = *(uint32_t *)txp;
+ else
+ temp = *txp;
writel(temp, ®s->tx_data);
- out_bytes--;
+ out_bytes -= step;
+ if (txp)
+ txp += step;
+ tx_lvl += step;
+ }
+ if (rx_lvl >= step) {
+ while (rx_lvl >= step) {
+ temp = readl(®s->rx_data);
+ if (priv->skip_preamble) {
+ if (temp == SPI_PREAMBLE_END_BYTE) {
+ priv->skip_preamble = 0;
+ stopping = 0;
+ }
+ } else {
+ if (rxp || stopping) {
+ if (step == 4)
+ *(uint32_t *)rxp = temp;
+ else
+ *rxp = temp;
+ rxp += step;
+ }
+ in_bytes -= step;
+ }
+ toread -= step;
+ rx_lvl -= step;
+ }
+ } else if (!toread) {
+ /*
+ * We have run out of input data, but haven't read
+ * enough bytes after the preamble yet. Read some more,
+ * and make sure that we transmit dummy bytes too, to
+ * keep things going.
+ */
+ assert(!out_bytes);
+ out_bytes = in_bytes;
+ toread = in_bytes;
+ txp = NULL;
+ spi_request_bytes(regs, toread, step);
}
- if (rx_lvl > 0 && in_bytes) {
- temp = readl(®s->rx_data);
- if (rxp)
- *rxp++ = temp;
- in_bytes--;
+ if (priv->skip_preamble && get_timer(start) > 100) {
+ debug("SPI timeout: in_bytes=%d, out_bytes=%d, ",
+ in_bytes, out_bytes);
+ return -ETIMEDOUT;
}
}
+
*dinp = rxp;
*doutp = txp;
+
+ return 0;
+}
+
+/**
+ * Activate the CS by driving it LOW
+ *
+ * @param slave Pointer to spi_slave to which controller has to
+ * communicate with
+ */
+static void spi_cs_activate(struct udevice *dev)
+{
+ struct udevice *bus = dev->parent;
+ struct exynos_spi_platdata *pdata = dev_get_platdata(bus);
+ struct exynos_spi_priv *priv = dev_get_priv(bus);
+
+ /* If it's too soon to do another transaction, wait */
+ if (pdata->deactivate_delay_us &&
+ priv->last_transaction_us) {
+ ulong delay_us; /* The delay completed so far */
+ delay_us = timer_get_us() - priv->last_transaction_us;
+ if (delay_us < pdata->deactivate_delay_us)
+ udelay(pdata->deactivate_delay_us - delay_us);
+ }
+
+ clrbits_le32(&priv->regs->cs_reg, SPI_SLAVE_SIG_INACT);
+ debug("Activate CS, bus '%s'\n", bus->name);
+ priv->skip_preamble = priv->mode & SPI_PREAMBLE;
}
/**
- * Transfer and receive data
+ * Deactivate the CS by driving it HIGH
*
- * @param slave Pointer to spi_slave to which controller has to
- * communicate with
- * @param bitlen No of bits to tranfer or receive
- * @param dout Pointer to transfer buffer
- * @param din Pointer to receive buffer
- * @param flags Flags for transfer begin and end
- * @return zero on success else a negative value
+ * @param slave Pointer to spi_slave to which controller has to
+ * communicate with
*/
-int spi_xfer(struct spi_slave *slave, unsigned int bitlen, const void *dout,
- void *din, unsigned long flags)
+static void spi_cs_deactivate(struct udevice *dev)
+{
+ struct udevice *bus = dev->parent;
+ struct exynos_spi_platdata *pdata = dev_get_platdata(bus);
+ struct exynos_spi_priv *priv = dev_get_priv(bus);
+
+ setbits_le32(&priv->regs->cs_reg, SPI_SLAVE_SIG_INACT);
+
+ /* Remember time of this transaction so we can honour the bus delay */
+ if (pdata->deactivate_delay_us)
+ priv->last_transaction_us = timer_get_us();
+
+ debug("Deactivate CS, bus '%s'\n", bus->name);
+}
+
+static int exynos_spi_ofdata_to_platdata(struct udevice *bus)
+{
+ struct exynos_spi_platdata *plat = bus->platdata;
+ const void *blob = gd->fdt_blob;
+ int node = bus->of_offset;
+
+ plat->regs = (struct exynos_spi *)fdtdec_get_addr(blob, node, "reg");
+ plat->periph_id = pinmux_decode_periph_id(blob, node);
+
+ if (plat->periph_id == PERIPH_ID_NONE) {
+ debug("%s: Invalid peripheral ID %d\n", __func__,
+ plat->periph_id);
+ return -FDT_ERR_NOTFOUND;
+ }
+
+ /* Use 500KHz as a suitable default */
+ plat->frequency = fdtdec_get_int(blob, node, "spi-max-frequency",
+ 500000);
+ plat->deactivate_delay_us = fdtdec_get_int(blob, node,
+ "spi-deactivate-delay", 0);
+ debug("%s: regs=%p, periph_id=%d, max-frequency=%d, deactivate_delay=%d\n",
+ __func__, plat->regs, plat->periph_id, plat->frequency,
+ plat->deactivate_delay_us);
+
+ return 0;
+}
+
+static int exynos_spi_probe(struct udevice *bus)
+{
+ struct exynos_spi_platdata *plat = dev_get_platdata(bus);
+ struct exynos_spi_priv *priv = dev_get_priv(bus);
+
+ priv->regs = plat->regs;
+ if (plat->periph_id == PERIPH_ID_SPI1 ||
+ plat->periph_id == PERIPH_ID_SPI2)
+ priv->fifo_size = 64;
+ else
+ priv->fifo_size = 256;
+
+ priv->skip_preamble = 0;
+ priv->last_transaction_us = timer_get_us();
+ priv->freq = plat->frequency;
+ priv->periph_id = plat->periph_id;
+
+ return 0;
+}
+
+static int exynos_spi_claim_bus(struct udevice *dev)
+{
+ struct udevice *bus = dev->parent;
+ struct exynos_spi_priv *priv = dev_get_priv(bus);
+
+ exynos_pinmux_config(priv->periph_id, PINMUX_FLAG_NONE);
+ spi_flush_fifo(priv->regs);
+
+ writel(SPI_FB_DELAY_180, &priv->regs->fb_clk);
+
+ return 0;
+}
+
+static int exynos_spi_release_bus(struct udevice *dev)
+{
+ struct udevice *bus = dev->parent;
+ struct exynos_spi_priv *priv = dev_get_priv(bus);
+
+ spi_flush_fifo(priv->regs);
+
+ return 0;
+}
+
+static int exynos_spi_xfer(struct udevice *dev, unsigned int bitlen,
+ const void *dout, void *din, unsigned long flags)
{
- struct exynos_spi_slave *spi_slave = to_exynos_spi(slave);
+ struct udevice *bus = dev->parent;
+ struct exynos_spi_priv *priv = dev_get_priv(bus);
int upto, todo;
int bytelen;
+ int ret = 0;
/* spi core configured to do 8 bit transfers */
if (bitlen % 8) {
/* Start the transaction, if necessary. */
if ((flags & SPI_XFER_BEGIN))
- spi_cs_activate(slave);
+ spi_cs_activate(dev);
- /* Exynos SPI limits each transfer to 65535 bytes */
- bytelen = bitlen / 8;
- for (upto = 0; upto < bytelen; upto += todo) {
- todo = min(bytelen - upto, (1 << 16) - 1);
- spi_rx_tx(spi_slave, todo, &din, &dout);
+ /*
+ * Exynos SPI limits each transfer to 65535 transfers. To keep
+ * things simple, allow a maximum of 65532 bytes. We could allow
+ * more in word mode, but the performance difference is small.
+ */
+ bytelen = bitlen / 8;
+ for (upto = 0; !ret && upto < bytelen; upto += todo) {
+ todo = min(bytelen - upto, (1 << 16) - 4);
+ ret = spi_rx_tx(priv, todo, &din, &dout, flags);
+ if (ret)
+ break;
}
/* Stop the transaction, if necessary. */
- if ((flags & SPI_XFER_END))
- spi_cs_deactivate(slave);
+ if ((flags & SPI_XFER_END) && !(priv->mode & SPI_SLAVE)) {
+ spi_cs_deactivate(dev);
+ if (priv->skip_preamble) {
+ assert(!priv->skip_preamble);
+ debug("Failed to complete premable transaction\n");
+ ret = -1;
+ }
+ }
- return 0;
+ return ret;
}
-/**
- * Validates the bus and chip select numbers
- *
- * @param bus ID of the bus that the slave is attached to
- * @param cs ID of the chip select connected to the slave
- * @return one on success else zero
- */
-int spi_cs_is_valid(unsigned int bus, unsigned int cs)
+static int exynos_spi_set_speed(struct udevice *bus, uint speed)
{
- return spi_get_bus(bus) && cs == 0;
-}
+ struct exynos_spi_platdata *plat = bus->platdata;
+ struct exynos_spi_priv *priv = dev_get_priv(bus);
+ int ret;
-/**
- * Activate the CS by driving it LOW
- *
- * @param slave Pointer to spi_slave to which controller has to
- * communicate with
- */
-void spi_cs_activate(struct spi_slave *slave)
-{
- struct exynos_spi_slave *spi_slave = to_exynos_spi(slave);
+ if (speed > plat->frequency)
+ speed = plat->frequency;
+ ret = set_spi_clk(priv->periph_id, speed);
+ if (ret)
+ return ret;
+ priv->freq = speed;
+ debug("%s: regs=%p, speed=%d\n", __func__, priv->regs, priv->freq);
- clrbits_le32(&spi_slave->regs->cs_reg, SPI_SLAVE_SIG_INACT);
- debug("Activate CS, bus %d\n", spi_slave->slave.bus);
+ return 0;
}
-/**
- * Deactivate the CS by driving it HIGH
- *
- * @param slave Pointer to spi_slave to which controller has to
- * communicate with
- */
-void spi_cs_deactivate(struct spi_slave *slave)
+static int exynos_spi_set_mode(struct udevice *bus, uint mode)
{
- struct exynos_spi_slave *spi_slave = to_exynos_spi(slave);
+ struct exynos_spi_priv *priv = dev_get_priv(bus);
+ uint32_t reg;
- setbits_le32(&spi_slave->regs->cs_reg, SPI_SLAVE_SIG_INACT);
- debug("Deactivate CS, bus %d\n", spi_slave->slave.bus);
-}
+ reg = readl(&priv->regs->ch_cfg);
+ reg &= ~(SPI_CH_CPHA_B | SPI_CH_CPOL_L);
-static inline struct exynos_spi *get_spi_base(int dev_index)
-{
- if (dev_index < 3)
- return (struct exynos_spi *)samsung_get_base_spi() + dev_index;
- else
- return (struct exynos_spi *)samsung_get_base_spi_isp() +
- (dev_index - 3);
-}
+ if (mode & SPI_CPHA)
+ reg |= SPI_CH_CPHA_B;
-/* Sadly there is no error return from this function */
-void spi_init(void)
-{
- int i;
- struct spi_bus *bus;
+ if (mode & SPI_CPOL)
+ reg |= SPI_CH_CPOL_L;
- for (i = 0; i < EXYNOS5_SPI_NUM_CONTROLLERS; i++) {
- bus = &spi_bus[i];
- bus->regs = get_spi_base(i);
- bus->periph_id = PERIPH_ID_SPI0 + i;
+ writel(reg, &priv->regs->ch_cfg);
+ priv->mode = mode;
+ debug("%s: regs=%p, mode=%d\n", __func__, priv->regs, priv->mode);
- /* Although Exynos5 supports upto 50Mhz speed,
- * we are setting it to 10Mhz for safe side
- */
- bus->frequency = 10000000;
- bus->inited = 1;
- }
+ return 0;
}
+
+static const struct dm_spi_ops exynos_spi_ops = {
+ .claim_bus = exynos_spi_claim_bus,
+ .release_bus = exynos_spi_release_bus,
+ .xfer = exynos_spi_xfer,
+ .set_speed = exynos_spi_set_speed,
+ .set_mode = exynos_spi_set_mode,
+ /*
+ * cs_info is not needed, since we require all chip selects to be
+ * in the device tree explicitly
+ */
+};
+
+static const struct udevice_id exynos_spi_ids[] = {
+ { .compatible = "samsung,exynos-spi" },
+ { }
+};
+
+U_BOOT_DRIVER(exynos_spi) = {
+ .name = "exynos_spi",
+ .id = UCLASS_SPI,
+ .of_match = exynos_spi_ids,
+ .ops = &exynos_spi_ops,
+ .ofdata_to_platdata = exynos_spi_ofdata_to_platdata,
+ .platdata_auto_alloc_size = sizeof(struct exynos_spi_platdata),
+ .priv_auto_alloc_size = sizeof(struct exynos_spi_priv),
+ .probe = exynos_spi_probe,
+};