TI QSPI controller has memory mapped port through which SPI flash
memories can be read using memcpy call. This patch adds support for
memory mapped read based on use_mmap_read flag.
When use_mmap_read flag is set, the controller is switched to memory
mapped interface by writing to QSPI_SPI_SWITCH_REG. The read_opcode,
read mode, dummy bytes are configured in QSPI_SPI_SETUPx_REG, then
memcpy is called to copy the requested data from flash to the rx_buf.
With this patch, the read speed increased from ~100kB/s to ~2.5MB/s on
DRA74 EVM.
Signed-off-by: Vignesh R <vigneshr@xxxxxx>
---
drivers/spi/spi-ti-qspi.c | 129 ++++++++++++++++++++++++++++++++++++++++++++--
1 file changed, 125 insertions(+), 4 deletions(-)
diff --git a/drivers/spi/spi-ti-qspi.c b/drivers/spi/spi-ti-qspi.c
index 5c0616870358..45844a227c5e 100644
--- a/drivers/spi/spi-ti-qspi.c
+++ b/drivers/spi/spi-ti-qspi.c
@@ -71,11 +71,8 @@ struct ti_qspi {
#define QSPI_SPI_CMD_REG (0x48)
#define QSPI_SPI_STATUS_REG (0x4c)
#define QSPI_SPI_DATA_REG (0x50)
-#define QSPI_SPI_SETUP0_REG (0x54)
+#define QSPI_SPI_SETUP_REG(n) (0x54 + 4 * n)
#define QSPI_SPI_SWITCH_REG (0x64)
-#define QSPI_SPI_SETUP1_REG (0x58)
-#define QSPI_SPI_SETUP2_REG (0x5c)
-#define QSPI_SPI_SETUP3_REG (0x60)
#define QSPI_SPI_DATA_REG_1 (0x68)
#define QSPI_SPI_DATA_REG_2 (0x6c)
#define QSPI_SPI_DATA_REG_3 (0x70)
@@ -118,6 +115,16 @@ struct ti_qspi {
#define QSPI_AUTOSUSPEND_TIMEOUT 2000
+#define MEM_CS_EN(n) ((n + 1) << 8)
+
+#define MM_SWITCH 0x1
+
+#define QSPI_SETUP_RD_NORMAL (0x0 << 12)
+#define QSPI_SETUP_RD_DUAL (0x1 << 12)
+#define QSPI_SETUP_RD_QUAD (0x3 << 12)
+#define QSPI_SETUP_ADDR_SHIFT 8
+#define QSPI_SETUP_DUMMY_SHIFT 10
+
static inline unsigned long ti_qspi_read(struct ti_qspi *qspi,
unsigned long reg)
{
@@ -335,6 +342,117 @@ static int qspi_transfer_msg(struct ti_qspi *qspi, struct spi_transfer *t)
return 0;
}
+static void ti_qspi_enable_memory_map(struct spi_device *spi)
+{
+ struct ti_qspi *qspi = spi_master_get_devdata(spi->master);
+ u32 val;
+
+ ti_qspi_write(qspi, MM_SWITCH, QSPI_SPI_SWITCH_REG);
+ if (qspi->ctrl_mod) {
+ val = readl(qspi->ctrl_base);
+ val |= MEM_CS_EN(spi->chip_select);
+ writel(val, qspi->ctrl_base);
+ }
+}
+
+static void ti_qspi_disable_memory_map(struct spi_device *spi)
+{
+ struct ti_qspi *qspi = spi_master_get_devdata(spi->master);
+ u32 val;
+
+ ti_qspi_write(qspi, 0, QSPI_SPI_SWITCH_REG);
+ if (qspi->ctrl_mod) {
+ val = readl(qspi->ctrl_base);
+ val &= ~MEM_CS_EN(spi->chip_select);
+ writel(val, qspi->ctrl_base);
+ }
+}
+
+static void ti_qspi_setup_mmap_read(struct spi_device *spi, u8
+ read_opcode, u8 addr_width,
+ u8 dummy_bytes)
+{
+ struct ti_qspi *qspi = spi_master_get_devdata(spi->master);
+ u32 mode = spi->mode & (SPI_RX_DUAL | SPI_RX_QUAD);
+ u32 memval = read_opcode;
+
+ switch (mode) {
+ case SPI_RX_QUAD:
+ memval |= QSPI_SETUP_RD_QUAD;
+ break;
+ case SPI_RX_DUAL:
+ memval |= QSPI_SETUP_RD_DUAL;
+ break;
+ default:
+ memval |= QSPI_SETUP_RD_NORMAL;
+ break;
+ }
+ memval |= ((addr_width - 1) << QSPI_SETUP_ADDR_SHIFT |
+ dummy_bytes << QSPI_SETUP_DUMMY_SHIFT);
+ ti_qspi_write(qspi, memval,
+ QSPI_SPI_SETUP_REG(spi->chip_select));
+}
+
+static unsigned int ti_qspi_cmd2addr(u8 *cmd, u8 addr_width)
+{
+ u32 addr;
+
+ /* cmd[0] is read opcode */
+ addr = cmd[1] << ((addr_width - 1) * 8);
+ addr |= cmd[2] << ((addr_width - 2) * 8);
+ addr |= cmd[3] << ((addr_width - 3) * 8);
+ addr |= cmd[4] << ((addr_width - 4) * 8);
+
+ return addr;
+}
+
+static int ti_qspi_mmap_read(struct spi_master *master,
+ struct spi_message *m)
+{
+ struct ti_qspi *qspi = spi_master_get_devdata(master);
+ struct spi_device *spi = m->spi;
+ struct spi_transfer *t;
+ u8 read_opcode = 0x3; /* Default normal read */
+ void *to = NULL;
+ u8 addr_width = 4, dummy_bytes = 0;
+ unsigned int len = 0, from = 0;
+ int status = 0;
+
+ mutex_lock(&qspi->list_lock);
+
+ /* disable WC interrupt during memcpy */
+ ti_qspi_write(qspi, QSPI_WC_INT_DISABLE, QSPI_INTR_ENABLE_CLEAR_REG);
+ ti_qspi_enable_memory_map(spi);
+ list_for_each_entry(t, &m->transfers, transfer_list) {
+ if (t->tx_buf) {
+ read_opcode = *((u8 *)t->tx_buf);
+ dummy_bytes = t->len - (addr_width + 1);
+ from = ti_qspi_cmd2addr((u8 *)t->tx_buf, addr_width);
+ }
+ if (t->rx_buf) {
+ to = ((void *)t->rx_buf);
+ len = t->len;
+ }
+ m->actual_length += t->len;
+ }
+ ti_qspi_setup_mmap_read(spi, read_opcode, addr_width,
+ dummy_bytes);
+
+ if (qspi_is_busy(qspi)) {
+ status = -EBUSY;
+ goto err;
+ }
+ memcpy(to, qspi->mmap_base + from, len);
+
+err:
+ ti_qspi_disable_memory_map(spi);
+ mutex_unlock(&qspi->list_lock);
+ m->status = status;
+ spi_finalize_current_message(master);
+
+ return status;
+}
+
static int ti_qspi_start_transfer_one(struct spi_master *master,
struct spi_message *m)
{
@@ -344,6 +462,9 @@ static int ti_qspi_start_transfer_one(struct spi_master *master,
int status = 0, ret;
int frame_length;
+ if (m->use_mmap_mode)
+ return ti_qspi_mmap_read(master, m);
+
/* setup device control reg */
qspi->dc = 0;
--
2.4.6
--
To unsubscribe from this list: send the line "unsubscribe linux-omap" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
