--- /dev/null
+/*
+ * Driver for Blackfin On-Chip SPI device
+ *
+ * Copyright (c) 2005-2010 Analog Devices Inc.
+ *
+ * SPDX-License-Identifier: GPL-2.0+
+ */
+
+/*#define DEBUG*/
+
+#include <common.h>
+#include <malloc.h>
+#include <spi.h>
+
+#include <asm/blackfin.h>
+#include <asm/clock.h>
+#include <asm/gpio.h>
+#include <asm/portmux.h>
+#include <asm/mach-common/bits/spi.h>
+
+struct bfin_spi_slave {
+ struct spi_slave slave;
+ void *mmr_base;
+ u16 ctl, baud, flg;
+};
+
+#define MAKE_SPI_FUNC(mmr, off) \
+static inline void write_##mmr(struct bfin_spi_slave *bss, u16 val) { bfin_write16(bss->mmr_base + off, val); } \
+static inline u16 read_##mmr(struct bfin_spi_slave *bss) { return bfin_read16(bss->mmr_base + off); }
+MAKE_SPI_FUNC(SPI_CTL, 0x00)
+MAKE_SPI_FUNC(SPI_FLG, 0x04)
+MAKE_SPI_FUNC(SPI_STAT, 0x08)
+MAKE_SPI_FUNC(SPI_TDBR, 0x0c)
+MAKE_SPI_FUNC(SPI_RDBR, 0x10)
+MAKE_SPI_FUNC(SPI_BAUD, 0x14)
+
+#define to_bfin_spi_slave(s) container_of(s, struct bfin_spi_slave, slave)
+
+#define gpio_cs(cs) ((cs) - MAX_CTRL_CS)
+#ifdef CONFIG_BFIN_SPI_GPIO_CS
+# define is_gpio_cs(cs) ((cs) > MAX_CTRL_CS)
+#else
+# define is_gpio_cs(cs) 0
+#endif
+
+int spi_cs_is_valid(unsigned int bus, unsigned int cs)
+{
+ if (is_gpio_cs(cs))
+ return gpio_is_valid(gpio_cs(cs));
+ else
+ return (cs >= 1 && cs <= MAX_CTRL_CS);
+}
+
+void spi_cs_activate(struct spi_slave *slave)
+{
+ struct bfin_spi_slave *bss = to_bfin_spi_slave(slave);
+
+ if (is_gpio_cs(slave->cs)) {
+ unsigned int cs = gpio_cs(slave->cs);
+ gpio_set_value(cs, bss->flg);
+ debug("%s: SPI_CS_GPIO:%x\n", __func__, gpio_get_value(cs));
+ } else {
+ write_SPI_FLG(bss,
+ (read_SPI_FLG(bss) &
+ ~((!bss->flg << 8) << slave->cs)) |
+ (1 << slave->cs));
+ debug("%s: SPI_FLG:%x\n", __func__, read_SPI_FLG(bss));
+ }
+
+ SSYNC();
+}
+
+void spi_cs_deactivate(struct spi_slave *slave)
+{
+ struct bfin_spi_slave *bss = to_bfin_spi_slave(slave);
+
+ if (is_gpio_cs(slave->cs)) {
+ unsigned int cs = gpio_cs(slave->cs);
+ gpio_set_value(cs, !bss->flg);
+ debug("%s: SPI_CS_GPIO:%x\n", __func__, gpio_get_value(cs));
+ } else {
+ u16 flg;
+
+ /* make sure we force the cs to deassert rather than let the
+ * pin float back up. otherwise, exact timings may not be
+ * met some of the time leading to random behavior (ugh).
+ */
+ flg = read_SPI_FLG(bss) | ((!bss->flg << 8) << slave->cs);
+ write_SPI_FLG(bss, flg);
+ SSYNC();
+ debug("%s: SPI_FLG:%x\n", __func__, read_SPI_FLG(bss));
+
+ flg &= ~(1 << slave->cs);
+ write_SPI_FLG(bss, flg);
+ debug("%s: SPI_FLG:%x\n", __func__, read_SPI_FLG(bss));
+ }
+
+ SSYNC();
+}
+
+void spi_init()
+{
+}
+
+#ifdef SPI_CTL
+# define SPI0_CTL SPI_CTL
+#endif
+
+#define SPI_PINS(n) \
+ [n] = { 0, P_SPI##n##_SCK, P_SPI##n##_MISO, P_SPI##n##_MOSI, 0 }
+static unsigned short pins[][5] = {
+#ifdef SPI0_CTL
+ SPI_PINS(0),
+#endif
+#ifdef SPI1_CTL
+ SPI_PINS(1),
+#endif
+#ifdef SPI2_CTL
+ SPI_PINS(2),
+#endif
+};
+
+#define SPI_CS_PINS(n) \
+ [n] = { \
+ P_SPI##n##_SSEL1, P_SPI##n##_SSEL2, P_SPI##n##_SSEL3, \
+ P_SPI##n##_SSEL4, P_SPI##n##_SSEL5, P_SPI##n##_SSEL6, \
+ P_SPI##n##_SSEL7, \
+ }
+static const unsigned short cs_pins[][7] = {
+#ifdef SPI0_CTL
+ SPI_CS_PINS(0),
+#endif
+#ifdef SPI1_CTL
+ SPI_CS_PINS(1),
+#endif
+#ifdef SPI2_CTL
+ SPI_CS_PINS(2),
+#endif
+};
+
+void spi_set_speed(struct spi_slave *slave, uint hz)
+{
+ struct bfin_spi_slave *bss = to_bfin_spi_slave(slave);
+ ulong clk;
+ u32 baud;
+
+ clk = get_spi_clk();
+ /* baud should be rounded up */
+ baud = DIV_ROUND_UP(clk, 2 * hz);
+ if (baud < 2)
+ baud = 2;
+ else if (baud > (u16)-1)
+ baud = -1;
+ bss->baud = baud;
+}
+
+struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs,
+ unsigned int max_hz, unsigned int mode)
+{
+ struct bfin_spi_slave *bss;
+ u32 mmr_base;
+
+ if (!spi_cs_is_valid(bus, cs))
+ return NULL;
+
+ switch (bus) {
+#ifdef SPI0_CTL
+ case 0:
+ mmr_base = SPI0_CTL; break;
+#endif
+#ifdef SPI1_CTL
+ case 1:
+ mmr_base = SPI1_CTL; break;
+#endif
+#ifdef SPI2_CTL
+ case 2:
+ mmr_base = SPI2_CTL; break;
+#endif
+ default:
+ debug("%s: invalid bus %u\n", __func__, bus);
+ return NULL;
+ }
+
+ bss = spi_alloc_slave(struct bfin_spi_slave, bus, cs);
+ if (!bss)
+ return NULL;
+
+ bss->mmr_base = (void *)mmr_base;
+ bss->ctl = SPE | MSTR | TDBR_CORE;
+ if (mode & SPI_CPHA) bss->ctl |= CPHA;
+ if (mode & SPI_CPOL) bss->ctl |= CPOL;
+ if (mode & SPI_LSB_FIRST) bss->ctl |= LSBF;
+ bss->flg = mode & SPI_CS_HIGH ? 1 : 0;
+ spi_set_speed(&bss->slave, max_hz);
+
+ debug("%s: bus:%i cs:%i mmr:%x ctl:%x baud:%i flg:%i\n", __func__,
+ bus, cs, mmr_base, bss->ctl, bss->baud, bss->flg);
+
+ return &bss->slave;
+}
+
+void spi_free_slave(struct spi_slave *slave)
+{
+ struct bfin_spi_slave *bss = to_bfin_spi_slave(slave);
+ free(bss);
+}
+
+int spi_claim_bus(struct spi_slave *slave)
+{
+ struct bfin_spi_slave *bss = to_bfin_spi_slave(slave);
+
+ debug("%s: bus:%i cs:%i\n", __func__, slave->bus, slave->cs);
+
+ if (is_gpio_cs(slave->cs)) {
+ unsigned int cs = gpio_cs(slave->cs);
+ gpio_request(cs, "bfin-spi");
+ gpio_direction_output(cs, !bss->flg);
+ pins[slave->bus][0] = P_DONTCARE;
+ } else
+ pins[slave->bus][0] = cs_pins[slave->bus][slave->cs - 1];
+ peripheral_request_list(pins[slave->bus], "bfin-spi");
+
+ write_SPI_CTL(bss, bss->ctl);
+ write_SPI_BAUD(bss, bss->baud);
+ SSYNC();
+
+ return 0;
+}
+
+void spi_release_bus(struct spi_slave *slave)
+{
+ struct bfin_spi_slave *bss = to_bfin_spi_slave(slave);
+
+ debug("%s: bus:%i cs:%i\n", __func__, slave->bus, slave->cs);
+
+ peripheral_free_list(pins[slave->bus]);
+ if (is_gpio_cs(slave->cs))
+ gpio_free(gpio_cs(slave->cs));
+
+ write_SPI_CTL(bss, 0);
+ SSYNC();
+}
+
+#ifndef CONFIG_BFIN_SPI_IDLE_VAL
+# define CONFIG_BFIN_SPI_IDLE_VAL 0xff
+#endif
+
+static int spi_pio_xfer(struct bfin_spi_slave *bss, const u8 *tx, u8 *rx,
+ uint bytes)
+{
+ /* discard invalid data and clear RXS */
+ read_SPI_RDBR(bss);
+ /* todo: take advantage of hardware fifos */
+ while (bytes--) {
+ u8 value = (tx ? *tx++ : CONFIG_BFIN_SPI_IDLE_VAL);
+ debug("%s: tx:%x ", __func__, value);
+ write_SPI_TDBR(bss, value);
+ SSYNC();
+ while ((read_SPI_STAT(bss) & TXS))
+ if (ctrlc())
+ return -1;
+ while (!(read_SPI_STAT(bss) & SPIF))
+ if (ctrlc())
+ return -1;
+ while (!(read_SPI_STAT(bss) & RXS))
+ if (ctrlc())
+ return -1;
+ value = read_SPI_RDBR(bss);
+ if (rx)
+ *rx++ = value;
+ debug("rx:%x\n", value);
+ }
+
+ return 0;
+}
+
+int spi_xfer(struct spi_slave *slave, unsigned int bitlen, const void *dout,
+ void *din, unsigned long flags)
+{
+ struct bfin_spi_slave *bss = to_bfin_spi_slave(slave);
+ const u8 *tx = dout;
+ u8 *rx = din;
+ uint bytes = bitlen / 8;
+ int ret = 0;
+
+ debug("%s: bus:%i cs:%i bitlen:%i bytes:%i flags:%lx\n", __func__,
+ slave->bus, slave->cs, bitlen, bytes, flags);
+
+ if (bitlen == 0)
+ goto done;
+
+ /* we can only do 8 bit transfers */
+ if (bitlen % 8) {
+ flags |= SPI_XFER_END;
+ goto done;
+ }
+
+ if (flags & SPI_XFER_BEGIN)
+ spi_cs_activate(slave);
+
+ ret = spi_pio_xfer(bss, tx, rx, bytes);
+
+ done:
+ if (flags & SPI_XFER_END)
+ spi_cs_deactivate(slave);
+
+ return ret;
+}
Code Review / kvmfornfv.git / blobdiff