[U-Boot] [PATCH 5/7 V3] SPI: Add SPI Driver for EXYNOS.
Rajeshwari Shinde
rajeshwari.s at samsung.com
Wed Aug 1 11:33:30 CEST 2012
This patch adds SPI driver for EXYNOS.
Signed-off-by: Simon Glass <sjg at chromium.org>
Signed-off-by: Padmavathi Venna <padma.v at samsung.com>
Signed-off-by: Gabe Black <gabeblack at google.com>
Signed-off-by: Rajeshwari Shinde <rajeshwari.s at samsung.com>
---
Changes in V2:
- None.
Changes in V3:
- Removed SPI_SLAVE flag.
arch/arm/include/asm/arch-exynos/spi.h | 78 +++++++
drivers/spi/Makefile | 1 +
drivers/spi/exynos_spi.c | 368 ++++++++++++++++++++++++++++++++
3 files changed, 447 insertions(+), 0 deletions(-)
create mode 100644 arch/arm/include/asm/arch-exynos/spi.h
create mode 100644 drivers/spi/exynos_spi.c
diff --git a/arch/arm/include/asm/arch-exynos/spi.h b/arch/arm/include/asm/arch-exynos/spi.h
new file mode 100644
index 0000000..7cab1e9
--- /dev/null
+++ b/arch/arm/include/asm/arch-exynos/spi.h
@@ -0,0 +1,78 @@
+/*
+ * (C) Copyright 2012 SAMSUNG Electronics
+ * Padmavathi Venna <padma.v at 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
+ */
+
+#ifndef __ASM_ARCH_EXYNOS_COMMON_SPI_H_
+#define __ASM_ARCH_EXYNOS_COMMON_SPI_H_
+
+#ifndef __ASSEMBLY__
+
+/* SPI peripheral register map; padded to 64KB */
+struct exynos_spi {
+ unsigned int ch_cfg; /* 0x00 */
+ unsigned char reserved0[4];
+ unsigned int mode_cfg; /* 0x08 */
+ unsigned int cs_reg; /* 0x0c */
+ unsigned char reserved1[4];
+ unsigned int spi_sts; /* 0x14 */
+ unsigned int tx_data; /* 0x18 */
+ unsigned int rx_data; /* 0x1c */
+ unsigned int pkt_cnt; /* 0x20 */
+ unsigned char reserved2[4];
+ unsigned char reserved3[4];
+ unsigned int fb_clk; /* 0x2c */
+ unsigned char padding[0xffd0];
+};
+
+#define EXYNOS_SPI_MAX_FREQ 50000000
+
+#define SPI_TIMEOUT_MS 10
+
+/* SPI_CHCFG */
+#define SPI_CH_HS_EN (1 << 6)
+#define SPI_CH_RST (1 << 5)
+#define SPI_SLAVE_MODE (1 << 4)
+#define SPI_CH_CPOL_L (1 << 3)
+#define SPI_CH_CPHA_B (1 << 2)
+#define SPI_RX_CH_ON (1 << 1)
+#define SPI_TX_CH_ON (1 << 0)
+
+/* SPI_MODECFG */
+#define SPI_MODE_CH_WIDTH_WORD (0x2 << 29)
+#define SPI_MODE_BUS_WIDTH_WORD (0x2 << 17)
+
+/* SPI_CSREG */
+#define SPI_SLAVE_SIG_INACT (1 << 0)
+
+/* SPI_STS */
+#define SPI_ST_TX_DONE (1 << 25)
+#define SPI_FIFO_LVL_MASK 0x1ff
+#define SPI_TX_LVL_OFFSET 6
+#define SPI_RX_LVL_OFFSET 15
+
+/* Feedback Delay */
+#define SPI_CLK_BYPASS (0 << 0)
+#define SPI_FB_DELAY_90 (1 << 0)
+#define SPI_FB_DELAY_180 (2 << 0)
+#define SPI_FB_DELAY_270 (3 << 0)
+
+/* Packet Count */
+#define SPI_PACKET_CNT_EN (1 << 16)
+
+#endif /* __ASSEMBLY__ */
+#endif
diff --git a/drivers/spi/Makefile b/drivers/spi/Makefile
index c20f1f2..f15adf0 100644
--- a/drivers/spi/Makefile
+++ b/drivers/spi/Makefile
@@ -33,6 +33,7 @@ COBJS-$(CONFIG_ATMEL_SPI) += atmel_spi.o
COBJS-$(CONFIG_BFIN_SPI) += bfin_spi.o
COBJS-$(CONFIG_CF_SPI) += cf_spi.o
COBJS-$(CONFIG_DAVINCI_SPI) += davinci_spi.o
+COBJS-$(CONFIG_EXYNOS_SPI) += exynos_spi.o
COBJS-$(CONFIG_KIRKWOOD_SPI) += kirkwood_spi.o
COBJS-$(CONFIG_MPC52XX_SPI) += mpc52xx_spi.o
COBJS-$(CONFIG_MPC8XXX_SPI) += mpc8xxx_spi.o
diff --git a/drivers/spi/exynos_spi.c b/drivers/spi/exynos_spi.c
new file mode 100644
index 0000000..a633f95
--- /dev/null
+++ b/drivers/spi/exynos_spi.c
@@ -0,0 +1,368 @@
+/*
+ * (C) Copyright 2012 SAMSUNG Electronics
+ * Padmavathi Venna <padma.v at 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
+ */
+
+#include <common.h>
+#include <malloc.h>
+#include <spi.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 */
+};
+
+/* 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;
+};
+
+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 = 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_SPI0)
+ spi_slave->fifo_size = 256;
+ else
+ spi_slave->fifo_size = 64;
+
+ 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
+ */
+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 = spi_set_clock_rate(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
+ */
+static void spi_request_bytes(struct exynos_spi *regs, int count)
+{
+ 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)
+{
+ struct exynos_spi *regs = spi_slave->regs;
+ uchar *rxp = *dinp;
+ const uchar *txp = *doutp;
+ int rx_lvl, tx_lvl;
+ uint out_bytes, in_bytes;
+
+ out_bytes = in_bytes = todo;
+
+ /*
+ * If there's something to send, do a software reset and set a
+ * transaction size.
+ */
+ spi_request_bytes(regs, todo);
+
+ /*
+ * Bytes are transmitted/received in pairs. Wait to receive all the
+ * data because then transmission will be done as well.
+ */
+ 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;
+ writel(temp, ®s->tx_data);
+ out_bytes--;
+ }
+ if (rx_lvl > 0 && in_bytes) {
+ temp = readl(®s->rx_data);
+ if (rxp)
+ *rxp++ = temp;
+ in_bytes--;
+ }
+ }
+ *dinp = rxp;
+ *doutp = txp;
+}
+
+/**
+ * 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;
+
+ /* 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 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);
+ }
+
+ /* Stop the transaction, if necessary. */
+ if ((flags & SPI_XFER_END))
+ spi_cs_deactivate(slave);
+
+ return 0;
+}
+
+/**
+ * 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);
+
+ clrbits_le32(&spi_slave->regs->cs_reg, SPI_SLAVE_SIG_INACT);
+ debug("Activate CS, bus %d\n", spi_slave->slave.bus);
+}
+
+/**
+ * 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);
+}
+
+/* Sadly there is no error return from this function */
+void spi_init(void)
+{
+ int i;
+ struct spi_bus *bus;
+ 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;
+ if (i == 1)
+ bus->frequency = 2500000;
+ else
+ bus->frequency = 500000;
+ bus->inited = 1;
+ bus_count++;
+ }
+}
--
1.7.4.4
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