--- /dev/null
+/*
+ * (C) Copyright 2012 SAMSUNG Electronics
+ * Padmavathi Venna <padma.v@samsung.com>
+ *
+ * SPDX-License-Identifier: GPL-2.0+
+ */
+
+#include <common.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/gpio.h>
+#include <asm/arch/pinmux.h>
+#include <asm/arch-exynos/spi.h>
+#include <asm/io.h>
+
+DECLARE_GLOBAL_DATA_PTR;
+
+/* Information about each SPI controller */
+struct spi_bus {
+ 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 */
+ int node;
+ 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];
+static unsigned int bus_count;
+
+struct exynos_spi_slave {
+ struct spi_slave slave;
+ 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;
+ struct spi_bus *bus; /* Pointer to our SPI bus info */
+ ulong last_transaction_us; /* Time of last transaction end */
+};
+
+static struct spi_bus *spi_get_bus(unsigned dev_index)
+{
+ if (dev_index < bus_count)
+ 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 = spi_alloc_slave(struct exynos_spi_slave, busnum, cs);
+ if (!spi_slave) {
+ debug("%s: Could not allocate spi_slave\n", __func__);
+ return NULL;
+ }
+
+ bus = &spi_bus[busnum];
+ spi_slave->bus = bus;
+ 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->skip_preamble = 0;
+ spi_slave->last_transaction_us = timer_get_us();
+
+ 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
+ */
+static void spi_flush_fifo(struct spi_slave *slave)
+{
+ 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)
+{
+ uint32_t spi_sts = readl(®s->spi_sts);
+
+ *rx_lvl = (spi_sts >> SPI_RX_LVL_OFFSET) & SPI_FIFO_LVL_MASK;
+ *tx_lvl = (spi_sts >> SPI_TX_LVL_OFFSET) & SPI_FIFO_LVL_MASK;
+}
+
+/**
+ * If there's something to transfer, do a software reset and set a
+ * transaction size.
+ *
+ * @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, int 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 int spi_rx_tx(struct exynos_spi_slave *spi_slave, int todo,
+ void **dinp, void const **doutp, unsigned long flags)
+{
+ struct exynos_spi *regs = spi_slave->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 = spi_slave->skip_preamble && (flags & SPI_XFER_END) &&
+ !(spi_slave->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) &&
+ !spi_slave->skip_preamble)
+ step = 4;
+
+ /*
+ * If there's something to send, do a software reset and set a
+ * transaction size.
+ */
+ 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);
+
+ /*
+ * Don't completely fill the txfifo, since we don't want our
+ * rxfifo to overflow, and it may already contain data.
+ */
+ while (tx_lvl < spi_slave->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 -= step;
+ if (txp)
+ txp += step;
+ tx_lvl += step;
+ }
+ if (rx_lvl >= step) {
+ while (rx_lvl >= step) {
+ temp = readl(®s->rx_data);
+ if (spi_slave->skip_preamble) {
+ if (temp == SPI_PREAMBLE_END_BYTE) {
+ spi_slave->skip_preamble = 0;
+ stopping = 0;
+ }
+ } else {
+ if (rxp || stopping) {
+ *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 (spi_slave->skip_preamble && get_timer(start) > 100) {
+ printf("SPI timeout: in_bytes=%d, out_bytes=%d, ",
+ in_bytes, out_bytes);
+ return -1;
+ }
+ }
+
+ *dinp = rxp;
+ *doutp = txp;
+
+ return 0;
+}
+
+/**
+ * Transfer and receive data
+ *
+ * @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
+ */
+int spi_xfer(struct spi_slave *slave, unsigned int bitlen, const void *dout,
+ void *din, unsigned long flags)
+{
+ struct exynos_spi_slave *spi_slave = to_exynos_spi(slave);
+ int upto, todo;
+ int bytelen;
+ int ret = 0;
+
+ /* spi core configured to do 8 bit transfers */
+ if (bitlen % 8) {
+ debug("Non byte aligned SPI transfer.\n");
+ return -1;
+ }
+
+ /* Start the transaction, if necessary. */
+ if ((flags & SPI_XFER_BEGIN))
+ spi_cs_activate(slave);
+
+ /*
+ * 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(spi_slave, todo, &din, &dout, flags);
+ if (ret)
+ break;
+ }
+
+ /* Stop the transaction, if necessary. */
+ if ((flags & SPI_XFER_END) && !(spi_slave->mode & SPI_SLAVE)) {
+ spi_cs_deactivate(slave);
+ if (spi_slave->skip_preamble) {
+ assert(!spi_slave->skip_preamble);
+ debug("Failed to complete premable transaction\n");
+ ret = -1;
+ }
+ }
+
+ 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)
+{
+ return spi_get_bus(bus) && cs == 0;
+}
+
+/**
+ * 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 it's too soon to do another transaction, wait */
+ if (spi_slave->bus->deactivate_delay_us &&
+ spi_slave->last_transaction_us) {
+ ulong delay_us; /* The delay completed so far */
+ delay_us = timer_get_us() - spi_slave->last_transaction_us;
+ if (delay_us < spi_slave->bus->deactivate_delay_us)
+ udelay(spi_slave->bus->deactivate_delay_us - delay_us);
+ }
+
+ clrbits_le32(&spi_slave->regs->cs_reg, SPI_SLAVE_SIG_INACT);
+ debug("Activate CS, bus %d\n", spi_slave->slave.bus);
+ spi_slave->skip_preamble = spi_slave->mode & SPI_PREAMBLE;
+
+ /* Remember time of this transaction so we can honour the bus delay */
+ if (spi_slave->bus->deactivate_delay_us)
+ spi_slave->last_transaction_us = timer_get_us();
+}
+
+/**
+ * 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)
+{
+ struct exynos_spi_slave *spi_slave = to_exynos_spi(slave);
+
+ setbits_le32(&spi_slave->regs->cs_reg, SPI_SLAVE_SIG_INACT);
+ debug("Deactivate CS, bus %d\n", spi_slave->slave.bus);
+}
+
+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);
+}
+
+/*
+ * Read the SPI config from the device tree node.
+ *
+ * @param blob FDT blob to read from
+ * @param node Node offset to read from
+ * @param bus SPI bus structure to fill with information
+ * @return 0 if ok, or -FDT_ERR_NOTFOUND if something was missing
+ */
+#ifdef CONFIG_OF_CONTROL
+static int spi_get_config(const void *blob, int node, struct spi_bus *bus)
+{
+ bus->node = node;
+ bus->regs = (struct exynos_spi *)fdtdec_get_addr(blob, node, "reg");
+ bus->periph_id = pinmux_decode_periph_id(blob, node);
+
+ if (bus->periph_id == PERIPH_ID_NONE) {
+ debug("%s: Invalid peripheral ID %d\n", __func__,
+ bus->periph_id);
+ return -FDT_ERR_NOTFOUND;
+ }
+
+ /* Use 500KHz as a suitable default */
+ bus->frequency = fdtdec_get_int(blob, node, "spi-max-frequency",
+ 500000);
+ bus->deactivate_delay_us = fdtdec_get_int(blob, node,
+ "spi-deactivate-delay", 0);
+
+ return 0;
+}
+
+/*
+ * Process a list of nodes, adding them to our list of SPI ports.
+ *
+ * @param blob fdt blob
+ * @param node_list list of nodes to process (any <=0 are ignored)
+ * @param count number of nodes to process
+ * @param is_dvc 1 if these are DVC ports, 0 if standard I2C
+ * @return 0 if ok, -1 on error
+ */
+static int process_nodes(const void *blob, int node_list[], int count)
+{
+ int i;
+
+ /* build the i2c_controllers[] for each controller */
+ for (i = 0; i < count; i++) {
+ int node = node_list[i];
+ struct spi_bus *bus;
+
+ if (node <= 0)
+ continue;
+
+ bus = &spi_bus[i];
+ if (spi_get_config(blob, node, bus)) {
+ printf("exynos spi_init: failed to decode bus %d\n",
+ i);
+ return -1;
+ }
+
+ debug("spi: controller bus %d at %p, periph_id %d\n",
+ i, bus->regs, bus->periph_id);
+ bus->inited = 1;
+ bus_count++;
+ }
+
+ return 0;
+}
+#endif
+
+/**
+ * Set up a new SPI slave for an fdt node
+ *
+ * @param blob Device tree blob
+ * @param node SPI peripheral node to use
+ * @return 0 if ok, -1 on error
+ */
+struct spi_slave *spi_setup_slave_fdt(const void *blob, int slave_node,
+ int spi_node)
+{
+ struct spi_bus *bus;
+ unsigned int i;
+
+ for (i = 0, bus = spi_bus; i < bus_count; i++, bus++) {
+ if (bus->node == spi_node)
+ return spi_base_setup_slave_fdt(blob, i, slave_node);
+ }
+
+ debug("%s: Failed to find bus node %d\n", __func__, spi_node);
+ return NULL;
+}
+
+/* Sadly there is no error return from this function */
+void spi_init(void)
+{
+ int count;
+
+#ifdef CONFIG_OF_CONTROL
+ int node_list[EXYNOS5_SPI_NUM_CONTROLLERS];
+ const void *blob = gd->fdt_blob;
+
+ count = fdtdec_find_aliases_for_id(blob, "spi",
+ COMPAT_SAMSUNG_EXYNOS_SPI, node_list,
+ EXYNOS5_SPI_NUM_CONTROLLERS);
+ if (process_nodes(blob, node_list, count))
+ return;
+
+#else
+ struct spi_bus *bus;
+
+ for (count = 0; count < EXYNOS5_SPI_NUM_CONTROLLERS; count++) {
+ bus = &spi_bus[count];
+ bus->regs = get_spi_base(count);
+ bus->periph_id = PERIPH_ID_SPI0 + count;
+
+ /* Although Exynos5 supports upto 50Mhz speed,
+ * we are setting it to 10Mhz for safe side
+ */
+ bus->frequency = 10000000;
+ bus->inited = 1;
+ bus->node = 0;
+ bus_count = EXYNOS5_SPI_NUM_CONTROLLERS;
+ }
+#endif
+}
Code Review / kvmfornfv.git / blobdiff