zephyr/drivers/spi/spi_xec_qmspi.c

682 lines
16 KiB
C

/*
* Copyright (c) 2019 Microchip Technology Inc.
*
* SPDX-License-Identifier: Apache-2.0
*/
#include <logging/log.h>
LOG_MODULE_REGISTER(spi_xec, CONFIG_SPI_LOG_LEVEL);
#include "spi_context.h"
#include <errno.h>
#include <device.h>
#include <drivers/spi.h>
#include <soc.h>
/* Device constant configuration parameters */
struct spi_qmspi_config {
QMSPI_Type *regs;
u32_t cs_timing;
u8_t girq;
u8_t girq_pos;
u8_t girq_nvic_aggr;
u8_t girq_nvic_direct;
u8_t irq_pri;
u8_t chip_sel;
u8_t width; /* 1(single), 2(dual), 4(quad) */
};
/* Device run time data */
struct spi_qmspi_data {
struct spi_context ctx;
};
static inline u32_t descr_rd(QMSPI_Type *regs, u32_t did)
{
uintptr_t raddr = (uintptr_t)regs + MCHP_QMSPI_DESC0_OFS +
((did & MCHP_QMSPI_C_NEXT_DESCR_MASK0) << 2);
return REG32(raddr);
}
static inline void descr_wr(QMSPI_Type *regs, u32_t did, u32_t val)
{
uintptr_t raddr = (uintptr_t)regs + MCHP_QMSPI_DESC0_OFS +
((did & MCHP_QMSPI_C_NEXT_DESCR_MASK0) << 2);
REG32(raddr) = val;
}
static inline void txb_wr8(QMSPI_Type *regs, u8_t data8)
{
REG8(&regs->TX_FIFO) = data8;
}
static inline u8_t rxb_rd8(QMSPI_Type *regs)
{
return REG8(&regs->RX_FIFO);
}
/*
* Program QMSPI frequency.
* MEC1501 base frequency is 48MHz. QMSPI frequency divider field in the
* mode register is defined as: 0=maximum divider of 256. Values 1 through
* 255 divide 48MHz by that value.
*/
static void qmspi_set_frequency(QMSPI_Type *regs, u32_t freq_hz)
{
u32_t div, qmode;
if (freq_hz == 0) {
div = 0; /* max divider = 256 */
} else {
div = MCHP_QMSPI_INPUT_CLOCK_FREQ_HZ / freq_hz;
if (div == 0) {
div = 1; /* max freq. divider = 1 */
} else if (div > 0xffu) {
div = 0u; /* max divider = 256 */
}
}
qmode = regs->MODE & ~(MCHP_QMSPI_M_FDIV_MASK);
qmode |= (div << MCHP_QMSPI_M_FDIV_POS) & MCHP_QMSPI_M_FDIV_MASK;
regs->MODE = qmode;
}
/*
* SPI signalling mode: CPOL and CPHA
* CPOL = 0 is clock idles low, 1 is clock idle high
* CPHA = 0 Transmitter changes data on trailing of preceding clock cycle.
* Receiver samples data on leading edge of clock cyle.
* 1 Transmitter changes data on leading edge of current clock cycle.
* Receiver samples data on the trailing edge of clock cycle.
* SPI Mode nomenclature:
* Mode CPOL CPHA
* 0 0 0
* 1 0 1
* 2 1 0
* 3 1 1
* MEC1501 has three controls, CPOL, CPHA for output and CPHA for input.
* SPI frequency < 48MHz
* Mode 0: CPOL=0 CHPA=0 (CHPA_MISO=0 and CHPA_MOSI=0)
* Mode 3: CPOL=1 CHPA=1 (CHPA_MISO=1 and CHPA_MOSI=1)
* Data sheet recommends when QMSPI set at max. SPI frequency (48MHz).
* SPI frequency == 48MHz sample and change data on same edge.
* Mode 0: CPOL=0 CHPA=0 (CHPA_MISO=1 and CHPA_MOSI=0)
* Mode 3: CPOL=1 CHPA=1 (CHPA_MISO=0 and CHPA_MOSI=1)
*/
const u8_t smode_tbl[4] = {
0x00u, 0x06u, 0x01u, 0x07u
};
const u8_t smode48_tbl[4] = {
0x04u, 0x02u, 0x05u, 0x03u
};
static void qmspi_set_signalling_mode(QMSPI_Type *regs, u32_t smode)
{
const u8_t *ptbl;
u32_t m;
ptbl = smode_tbl;
if (((regs->MODE >> MCHP_QMSPI_M_FDIV_POS) &
MCHP_QMSPI_M_FDIV_MASK0) == 1) {
ptbl = smode48_tbl;
}
m = (u32_t)ptbl[smode & 0x03];
regs->MODE = (regs->MODE & ~(MCHP_QMSPI_M_SIG_MASK))
| (m << MCHP_QMSPI_M_SIG_POS);
}
/*
* QMSPI HW support single, dual, and quad.
* Return QMSPI Control/Descriptor register encoded value.
*/
static u32_t qmspi_config_get_lines(const struct spi_config *config)
{
u32_t qlines;
switch (config->operation & SPI_LINES_MASK) {
case SPI_LINES_SINGLE:
qlines = MCHP_QMSPI_C_IFM_1X;
break;
#if DT_SPI_XEC_QMSPI_0_LINES > 1
case SPI_LINES_DUAL:
qlines = MCHP_QMSPI_C_IFM_2X;
break;
#endif
#if DT_SPI_XEC_QMSPI_0_LINES > 2
case SPI_LINES_QUAD:
qlines = MCHP_QMSPI_C_IFM_4X;
break;
#endif
default:
qlines = 0xffu;
}
return qlines;
}
/*
* Configure QMSPI.
* NOTE: QMSPI can control two chip selects. At this time we use CS0# only.
*/
static int qmspi_configure(struct device *dev,
const struct spi_config *config)
{
const struct spi_qmspi_config *cfg = dev->config->config_info;
struct spi_qmspi_data *data = dev->driver_data;
QMSPI_Type *regs = cfg->regs;
u32_t smode;
if (spi_context_configured(&data->ctx, config)) {
return 0;
}
if (config->operation & (SPI_TRANSFER_LSB | SPI_OP_MODE_SLAVE
| SPI_MODE_LOOP)) {
return -ENOTSUP;
}
smode = qmspi_config_get_lines(config);
if (smode == 0xff) {
return -ENOTSUP;
}
regs->CTRL = smode;
/* Use the requested or next highest possible frequency */
qmspi_set_frequency(regs, config->frequency);
smode = 0;
if ((config->operation & SPI_MODE_CPHA) != 0U) {
smode |= (1ul << 0);
}
if ((config->operation & SPI_MODE_CPOL) != 0U) {
smode |= (1ul << 1);
}
qmspi_set_signalling_mode(regs, smode);
if (SPI_WORD_SIZE_GET(config->operation) != 8) {
return -ENOTSUP;
}
/* chip select */
smode = regs->MODE & ~(MCHP_QMSPI_M_CS_MASK);
#if DT_SPI_XEC_QMSPI_0_CHIP_SELECT == 0
smode |= MCHP_QMSPI_M_CS0;
#else
smode |= MCHP_QMSPI_M_CS1;
#endif
regs->MODE = smode;
/* chip select timing */
regs->CSTM = cfg->cs_timing;
data->ctx.config = config;
/* Add driver specific data to SPI context structure */
spi_context_cs_configure(&data->ctx);
regs->MODE |= MCHP_QMSPI_M_ACTIVATE;
return 0;
}
/*
* Transmit dummy clocks - QMSPI will generate requested number of
* SPI clocks with I/O pins tri-stated.
* Single mode: 1 bit per clock -> IFM field = 00b. Max 0x7fff clocks
* Dual mode: 2 bits per clock -> IFM field = 01b. Max 0x3fff clocks
* Quad mode: 4 bits per clock -> IFM fiels = 1xb. Max 0x1fff clocks
* QMSPI unit size set to bits.
*/
static int qmspi_tx_dummy_clocks(QMSPI_Type *regs, u32_t nclocks)
{
u32_t descr, ifm, qstatus;
ifm = regs->CTRL & MCHP_QMSPI_C_IFM_MASK;
descr = ifm | MCHP_QMSPI_C_TX_DIS | MCHP_QMSPI_C_XFR_UNITS_BITS
| MCHP_QMSPI_C_DESCR_LAST | MCHP_QMSPI_C_DESCR0;
if (ifm & 0x01) {
nclocks <<= 1;
} else if (ifm & 0x02) {
nclocks <<= 2;
}
descr |= (nclocks << MCHP_QMSPI_C_XFR_NUNITS_POS);
descr_wr(regs, 0, descr);
regs->CTRL |= MCHP_QMSPI_C_DESCR_EN;
regs->IEN = 0;
regs->STS = 0xfffffffful;
regs->EXE = MCHP_QMSPI_EXE_START;
do {
qstatus = regs->STS;
if (qstatus & MCHP_QMSPI_STS_PROG_ERR) {
return -EIO;
}
} while ((qstatus & MCHP_QMSPI_STS_DONE) == 0);
return 0;
}
/*
* Return unit size power of 2 given number of bytes to transfer.
*/
static u32_t qlen_shift(u32_t len)
{
u32_t ushift;
/* is len a multiple of 4 or 16? */
if ((len & 0x0F) == 0) {
ushift = 4;
} else if ((len & 0x03) == 0) {
ushift = 2;
} else {
ushift = 0;
}
return ushift;
}
/*
* Return QMSPI unit size of the number of units field in QMSPI
* control/descriptor register.
* Input: power of 2 unit size 4, 2, or 0(default) corresponding
* to 16, 4, or 1 byte units.
*/
static u32_t get_qunits(u32_t qshift)
{
if (qshift == 4) {
return MCHP_QMSPI_C_XFR_UNITS_16;
} else if (qshift == 2) {
return MCHP_QMSPI_C_XFR_UNITS_4;
} else {
return MCHP_QMSPI_C_XFR_UNITS_1;
}
}
/*
* Allocate(build) one or more descriptors.
* QMSPI contains 16 32-bit descriptor registers used as a linked
* list of operations. Using only 32-bits there are limitations.
* Each descriptor is limited to 0x7FFF units where unit size can
* be 1, 4, or 16 bytes. A descriptor can perform transmit or receive
* but not both simultaneously. Order of descriptor processing is specified
* by the first descriptor field of the control register, the next descriptor
* fields in each descriptor, and the descriptors last flag.
*/
static int qmspi_descr_alloc(QMSPI_Type *regs, const struct spi_buf *txb,
int didx, bool is_tx)
{
u32_t descr, qshift, n, nu;
int dn;
if (didx >= MCHP_QMSPI_MAX_DESCR) {
return -EAGAIN;
}
if (txb->len == 0) {
return didx; /* nothing to do */
}
/* b[1:0] IFM and b[3:2] transmit mode */
descr = (regs->CTRL & MCHP_QMSPI_C_IFM_MASK);
if (is_tx) {
descr |= MCHP_QMSPI_C_TX_DATA;
} else {
descr |= MCHP_QMSPI_C_RX_EN;
}
/* b[11:10] unit size 1, 4, or 16 bytes */
qshift = qlen_shift(txb->len);
nu = txb->len >> qshift;
descr |= get_qunits(qshift);
do {
descr &= 0x0FFFul;
dn = didx + 1;
/* b[15:12] next descriptor pointer */
descr |= ((dn & MCHP_QMSPI_C_NEXT_DESCR_MASK0) <<
MCHP_QMSPI_C_NEXT_DESCR_POS);
n = nu;
if (n > MCHP_QMSPI_C_MAX_UNITS) {
n = MCHP_QMSPI_C_MAX_UNITS;
}
descr |= (n << MCHP_QMSPI_C_XFR_NUNITS_POS);
descr_wr(regs, didx, descr);
if (dn < MCHP_QMSPI_MAX_DESCR) {
didx++;
} else {
return -EAGAIN;
}
nu -= n;
} while (nu);
return dn;
}
static int qmspi_tx(QMSPI_Type *regs, const struct spi_buf *tx_buf,
bool close)
{
const u8_t *p = tx_buf->buf;
size_t tlen = tx_buf->len;
u32_t descr;
int didx;
if (tlen == 0) {
return 0;
}
/* Buffer pointer is NULL and number of bytes != 0 ? */
if (p == NULL) {
return qmspi_tx_dummy_clocks(regs, tlen);
}
didx = qmspi_descr_alloc(regs, tx_buf, 0, true);
if (didx < 0) {
return didx;
}
/* didx points to last allocated descriptor + 1 */
__ASSERT(didx > 0, "QMSPI descriptor index=%d expected > 0\n", didx);
didx--;
descr = descr_rd(regs, didx) | MCHP_QMSPI_C_DESCR_LAST;
if (close) {
descr |= MCHP_QMSPI_C_CLOSE;
}
descr_wr(regs, didx, descr);
regs->CTRL = (regs->CTRL & MCHP_QMSPI_C_IFM_MASK) |
MCHP_QMSPI_C_DESCR_EN | MCHP_QMSPI_C_DESCR0;
regs->IEN = 0;
regs->STS = 0xfffffffful;
/* preload TX_FIFO */
while (tlen) {
tlen--;
txb_wr8(regs, *p);
p++;
if (regs->STS & MCHP_QMSPI_STS_TXBF_RO) {
break;
}
}
regs->EXE = MCHP_QMSPI_EXE_START;
if (regs->STS & MCHP_QMSPI_STS_PROG_ERR) {
return -EIO;
}
while (tlen) {
while (regs->STS & MCHP_QMSPI_STS_TXBF_RO) {
}
txb_wr8(regs, *p);
p++;
tlen--;
}
/* Wait for TX FIFO to drain and last byte to be clocked out */
for (;;) {
if (regs->STS & MCHP_QMSPI_STS_DONE) {
break;
}
}
return 0;
}
static int qmspi_rx(QMSPI_Type *regs, const struct spi_buf *rx_buf,
bool close)
{
u8_t *p = rx_buf->buf;
size_t rlen = rx_buf->len;
u32_t descr;
int didx;
u8_t data_byte;
if (rlen == 0) {
return 0;
}
didx = qmspi_descr_alloc(regs, rx_buf, 0, false);
if (didx < 0) {
return didx;
}
/* didx points to last allocated descriptor + 1 */
__ASSERT_NO_MSG(didx > 0);
didx--;
descr = descr_rd(regs, didx) | MCHP_QMSPI_C_DESCR_LAST;
if (close) {
descr |= MCHP_QMSPI_C_CLOSE;
}
descr_wr(regs, didx, descr);
regs->CTRL = (regs->CTRL & MCHP_QMSPI_C_IFM_MASK)
| MCHP_QMSPI_C_DESCR_EN | MCHP_QMSPI_C_DESCR0;
regs->IEN = 0;
regs->STS = 0xfffffffful;
/*
* Trigger read based on the descriptor(s) programmed above.
* QMSPI will generate clocks until the RX FIFO is filled.
* More clocks will be generated as we pull bytes from the RX FIFO.
* QMSPI Programming error will be triggered after start if
* descriptors were programmed options that cannot be enabled
* simultaneously.
*/
regs->EXE = MCHP_QMSPI_EXE_START;
if (regs->STS & MCHP_QMSPI_STS_PROG_ERR) {
return -EIO;
}
while (rlen) {
if (!(regs->STS & MCHP_QMSPI_STS_RXBE_RO)) {
data_byte = rxb_rd8(regs);
if (p != NULL) {
*p++ = data_byte;
}
rlen--;
}
}
return 0;
}
static int qmspi_transceive(struct device *dev,
const struct spi_config *config,
const struct spi_buf_set *tx_bufs,
const struct spi_buf_set *rx_bufs)
{
const struct spi_qmspi_config *cfg = dev->config->config_info;
struct spi_qmspi_data *data = dev->driver_data;
QMSPI_Type *regs = cfg->regs;
const struct spi_buf *ptx;
const struct spi_buf *prx;
size_t nb;
u32_t descr, last_didx;
int err;
spi_context_lock(&data->ctx, false, NULL);
err = qmspi_configure(dev, config);
if (err != 0) {
goto done;
}
spi_context_cs_control(&data->ctx, true);
if (tx_bufs != NULL) {
ptx = tx_bufs->buffers;
nb = tx_bufs->count;
while (nb--) {
err = qmspi_tx(regs, ptx, false);
if (err != 0) {
goto done;
}
ptx++;
}
}
if (rx_bufs != NULL) {
prx = rx_bufs->buffers;
nb = rx_bufs->count;
while (nb--) {
err = qmspi_rx(regs, prx, false);
if (err != 0) {
goto done;
}
prx++;
}
}
/*
* If caller doesn't need CS# held asserted then find the last
* descriptor, set its close flag, and set stop.
*/
if (!(config->operation & SPI_HOLD_ON_CS)) {
/* Get last descriptor from status register */
last_didx = (regs->STS >> MCHP_QMSPI_C_NEXT_DESCR_POS)
& MCHP_QMSPI_C_NEXT_DESCR_MASK0;
descr = descr_rd(regs, last_didx) | MCHP_QMSPI_C_CLOSE;
descr_wr(regs, last_didx, descr);
regs->EXE = MCHP_QMSPI_EXE_STOP;
}
spi_context_cs_control(&data->ctx, false);
done:
spi_context_release(&data->ctx, err);
return err;
}
static int qmspi_transceive_sync(struct device *dev,
const struct spi_config *config,
const struct spi_buf_set *tx_bufs,
const struct spi_buf_set *rx_bufs)
{
return qmspi_transceive(dev, config, tx_bufs, rx_bufs);
}
#ifdef CONFIG_SPI_ASYNC
static int qmspi_transceive_async(struct device *dev,
const struct spi_config *config,
const struct spi_buf_set *tx_bufs,
const struct spi_buf_set *rx_bufs,
struct k_poll_signal *async)
{
return -ENOTSUP;
}
#endif
static int qmspi_release(struct device *dev,
const struct spi_config *config)
{
struct spi_qmspi_data *data = dev->driver_data;
const struct spi_qmspi_config *cfg = dev->config->config_info;
QMSPI_Type *regs = cfg->regs;
/* Force CS# to de-assert on next unit boundary */
regs->EXE = MCHP_QMSPI_EXE_STOP;
while (regs->STS & MCHP_QMSPI_STS_ACTIVE_RO) {
}
spi_context_unlock_unconditionally(&data->ctx);
return 0;
}
/*
* Initialize QMSPI controller.
* Disable sleep control.
* Disable and clear interrupt status.
* Initialize SPI context.
* QMSPI will be configured and enabled when the transceive API is called.
*/
static int qmspi_init(struct device *dev)
{
const struct spi_qmspi_config *cfg = dev->config->config_info;
struct spi_qmspi_data *data = dev->driver_data;
QMSPI_Type *regs = cfg->regs;
mchp_pcr_periph_slp_ctrl(PCR_QMSPI, MCHP_PCR_SLEEP_DIS);
regs->MODE = MCHP_QMSPI_M_SRST;
MCHP_GIRQ_CLR_EN(cfg->girq, cfg->girq_pos);
MCHP_GIRQ_SRC_CLR(cfg->girq, cfg->girq_pos);
MCHP_GIRQ_BLK_CLREN(cfg->girq);
NVIC_ClearPendingIRQ(cfg->girq_nvic_direct);
spi_context_unlock_unconditionally(&data->ctx);
return 0;
}
static const struct spi_driver_api spi_qmspi_driver_api = {
.transceive = qmspi_transceive_sync,
#ifdef CONFIG_SPI_ASYNC
.transceive_async = qmspi_transceive_async,
#endif
.release = qmspi_release,
};
#define XEC_QMSPI_CS_TIMING_VAL(a, b, c, d) (((a) & 0xFu) \
| (((b) & 0xFu) << 8) \
| (((c) & 0xFu) << 16) \
| (((d) & 0xFu) << 24))
#define XEC_QMSPI_0_CS_TIMING XEC_QMSPI_CS_TIMING_VAL( \
DT_SPI_XEC_QMSPI_0_DCSCKON, \
DT_SPI_XEC_QMSPI_0_DCKCSOFF, \
DT_SPI_XEC_QMSPI_0_DLDH, \
DT_SPI_XEC_QMSPI_0_DCSDA)
#ifdef DT_SPI_XEC_QMSPI_0_BASE_ADDRESS
static const struct spi_qmspi_config spi_qmspi_0_config = {
.regs = (QMSPI_Type *)DT_SPI_XEC_QMSPI_0_BASE_ADDRESS,
.cs_timing = XEC_QMSPI_0_CS_TIMING,
.girq = MCHP_QMSPI_GIRQ_NUM,
.girq_pos = MCHP_QMSPI_GIRQ_POS,
.girq_nvic_direct = MCHP_QMSPI_GIRQ_NVIC_DIRECT,
.irq_pri = DT_SPI_XEC_QMSPI_0_IRQ_PRI,
.chip_sel = DT_SPI_XEC_QMSPI_0_CHIP_SELECT,
.width = DT_SPI_XEC_QMSPI_0_LINES
};
static struct spi_qmspi_data spi_qmspi_0_dev_data = {
SPI_CONTEXT_INIT_LOCK(spi_qmspi_0_dev_data, ctx),
SPI_CONTEXT_INIT_SYNC(spi_qmspi_0_dev_data, ctx)
};
DEVICE_AND_API_INIT(spi_xec_qmspi_0,
DT_SPI_XEC_QMSPI_0_LABEL,
&qmspi_init, &spi_qmspi_0_dev_data,
&spi_qmspi_0_config, POST_KERNEL,
CONFIG_SPI_INIT_PRIORITY, &spi_qmspi_driver_api);
#endif /* DT_SPI_XEC_QMSPI_0_BASE_ADDRESS */