MRVL Xfer overlay extends xSPI capabilities to support non-memory SPI
operations. The Marvell overlay, combined with a generic command, allows
for full-duplex SPI transactions. It also enables transactions with
undetermined lengths using the cs_hold parameter and the ability to
extend CS signal assertion, even if the xSPI block requests CS signal
de-assertion.
Signed-off-by: Witold Sadowski <wsadowski@xxxxxxxxxxx>
---
drivers/spi/spi-cadence-xspi.c | 245 +++++++++++++++++++++++++++++++++
1 file changed, 245 insertions(+)
diff --git a/drivers/spi/spi-cadence-xspi.c b/drivers/spi/spi-cadence-xspi.c
index 490bba7a0fc8..7279a73162ce 100644
--- a/drivers/spi/spi-cadence-xspi.c
+++ b/drivers/spi/spi-cadence-xspi.c
@@ -219,6 +219,7 @@
#define CDNS_XSPI_DLL_RST_N BIT(24)
#define CDNS_XSPI_DLL_LOCK BIT(0)
+
/* Marvell overlay registers - clock */
#define MRVL_XSPI_CLK_CTRL_AUX_REG 0x2020
#define MRVL_XSPI_CLK_ENABLE BIT(0)
@@ -232,6 +233,22 @@
#define MRVL_XSPI_SPIX_INTR_AUX 0x2000
#define MRVL_MSIX_CLEAR_IRQ 0x01
+/* Marvell overlay registers - xfer */
+#define MRVL_XFER_FUNC_CTRL 0x210
+#define MRVL_XFER_FUNC_CTRL_READ_DATA(i) (0x000 + 8 * (i))
+#define MRVL_XFER_SOFT_RESET BIT(11)
+#define MRVL_XFER_CS_N_HOLD GENMASK(9, 6)
+#define MRVL_XFER_RECEIVE_ENABLE BIT(4)
+#define MRVL_XFER_FUNC_ENABLE BIT(3)
+#define MRVL_XFER_CLK_CAPTURE_POL BIT(2)
+#define MRVL_XFER_CLK_DRIVE_POL BIT(1)
+#define MRVL_XFER_FUNC_START BIT(0)
+#define MRVL_XFER_QWORD_COUNT 32
+#define MRVL_XFER_QWORD_BYTECOUNT 8
+
+#define MRVL_XSPI_POLL_TIMEOUT_US 1000
+#define MRVL_XSPI_POLL_DELAY_US 10
+
enum cdns_xspi_stig_instr_type {
CDNS_XSPI_STIG_INSTR_TYPE_0,
CDNS_XSPI_STIG_INSTR_TYPE_1,
@@ -256,6 +273,7 @@ struct cdns_xspi_dev {
void __iomem *iobase;
void __iomem *auxbase;
void __iomem *sdmabase;
+ void __iomem *xferbase;
int irq;
int cur_cs;
@@ -270,6 +288,9 @@ struct cdns_xspi_dev {
const void *out_buffer;
u8 hw_num_banks;
+
+ bool xfer_in_progress;
+ int current_xfer_qword;
};
struct cdns_xspi_driver_data {
@@ -836,6 +857,220 @@ static int cdns_xspi_setup(struct spi_device *spi_dev)
return 0;
}
+static int cdns_xspi_prepare_generic(int cs, const void *dout, int len, int glue, u32 *cmd_regs)
+{
+ u8 *data = (u8 *)dout;
+ int i;
+ int data_counter = 0;
+
+ memset(cmd_regs, 0x00, 6*4);
+
+ if (len > 7) {
+ for (i = (len >= 10 ? 2 : len - 8); i >= 0 ; i--)
+ cmd_regs[3] |= data[data_counter++] << (8*i);
+ }
+ if (len > 3) {
+ for (i = (len >= 7 ? 3 : len - 4); i >= 0; i--)
+ cmd_regs[2] |= data[data_counter++] << (8*i);
+ }
+ for (i = (len >= 3 ? 2 : len - 1); i >= 0 ; i--)
+ cmd_regs[1] |= data[data_counter++] << (8 + 8*i);
+
+ cmd_regs[1] |= 96;
+ cmd_regs[3] |= len << 24;
+ cmd_regs[4] |= cs << 12;
+
+ if (glue == 1)
+ cmd_regs[4] |= 1 << 28;
+
+ return 0;
+}
+
+static unsigned char reverse_bits(unsigned char num)
+{
+ unsigned int count = sizeof(num) * 8 - 1;
+ unsigned int reverse_num = num;
+
+ num >>= 1;
+ while (num) {
+ reverse_num <<= 1;
+ reverse_num |= num & 1;
+ num >>= 1;
+ count--;
+ }
+ reverse_num <<= count;
+ return reverse_num;
+}
+
+static void cdns_xspi_read_single_qword(struct cdns_xspi_dev *cdns_xspi, u8 **buffer)
+{
+ u64 d = readq(cdns_xspi->xferbase +
+ MRVL_XFER_FUNC_CTRL_READ_DATA(cdns_xspi->current_xfer_qword));
+ u8 *ptr = (u8 *)&d;
+ int k;
+
+ for (k = 0; k < 8; k++) {
+ u8 val = reverse_bits((ptr[k]));
+ **buffer = val;
+ *buffer = *buffer + 1;
+ }
+
+ cdns_xspi->current_xfer_qword++;
+ cdns_xspi->current_xfer_qword %= MRVL_XFER_QWORD_COUNT;
+}
+
+static void cdns_xspi_finish_read(struct cdns_xspi_dev *cdns_xspi, u8 **buffer, u32 data_count)
+{
+ u64 d = readq(cdns_xspi->xferbase +
+ MRVL_XFER_FUNC_CTRL_READ_DATA(cdns_xspi->current_xfer_qword));
+ u8 *ptr = (u8 *)&d;
+ int k;
+
+ for (k = 0; k < data_count % MRVL_XFER_QWORD_BYTECOUNT; k++) {
+ u8 val = reverse_bits((ptr[k]));
+ **buffer = val;
+ *buffer = *buffer + 1;
+ }
+
+ cdns_xspi->current_xfer_qword++;
+ cdns_xspi->current_xfer_qword %= MRVL_XFER_QWORD_COUNT;
+}
+
+static int cdns_xspi_prepare_transfer(int cs, int dir, int len, u32 *cmd_regs)
+{
+ memset(cmd_regs, 0x00, 6*4);
+
+ cmd_regs[1] |= 127;
+ cmd_regs[2] |= len << 16;
+ cmd_regs[4] |= dir << 4; //dir = 0 read, dir =1 write
+ cmd_regs[4] |= cs << 12;
+
+ return 0;
+}
+
+static bool cdns_xspi_stig_ready(struct cdns_xspi_dev *cdns_xspi, bool sleep)
+{
+ u32 ctrl_stat;
+
+ return readl_relaxed_poll_timeout
+ (cdns_xspi->iobase + CDNS_XSPI_CTRL_STATUS_REG,
+ ctrl_stat,
+ ((ctrl_stat & BIT(3)) == 0),
+ sleep ? MRVL_XSPI_POLL_DELAY_US : 0,
+ sleep ? MRVL_XSPI_POLL_TIMEOUT_US : 0);
+}
+
+static bool cdns_xspi_sdma_ready(struct cdns_xspi_dev *cdns_xspi, bool sleep)
+{
+ u32 ctrl_stat;
+
+ return readl_relaxed_poll_timeout
+ (cdns_xspi->iobase + CDNS_XSPI_INTR_STATUS_REG,
+ ctrl_stat,
+ (ctrl_stat & CDNS_XSPI_SDMA_TRIGGER),
+ sleep ? MRVL_XSPI_POLL_DELAY_US : 0,
+ sleep ? MRVL_XSPI_POLL_TIMEOUT_US : 0);
+}
+
+static int cdns_xspi_transfer_one_message_b0(struct spi_controller *controller,
+ struct spi_message *m)
+{
+ struct cdns_xspi_dev *cdns_xspi = spi_controller_get_devdata(controller);
+ struct spi_device *spi = m->spi;
+ struct spi_transfer *t = NULL;
+
+ const int max_len = MRVL_XFER_QWORD_BYTECOUNT * MRVL_XFER_QWORD_COUNT;
+ int current_cycle_count;
+ int cs = spi_get_chipselect(spi, 0);
+ int cs_change = 0;
+
+ /* Enable xfer state machine */
+ if (!cdns_xspi->xfer_in_progress) {
+ u32 xfer_control = readl(cdns_xspi->xferbase + MRVL_XFER_FUNC_CTRL);
+
+ cdns_xspi->current_xfer_qword = 0;
+ cdns_xspi->xfer_in_progress = true;
+ xfer_control |= (MRVL_XFER_RECEIVE_ENABLE |
+ MRVL_XFER_CLK_CAPTURE_POL |
+ MRVL_XFER_FUNC_START |
+ MRVL_XFER_SOFT_RESET |
+ FIELD_PREP(MRVL_XFER_CS_N_HOLD, (1 << cs)));
+ xfer_control &= ~(MRVL_XFER_FUNC_ENABLE | MRVL_XFER_CLK_DRIVE_POL);
+ writel(xfer_control, cdns_xspi->xferbase + MRVL_XFER_FUNC_CTRL);
+ }
+
+ list_for_each_entry(t, &m->transfers, transfer_list) {
+ u8 *txd = (u8 *) t->tx_buf;
+ u8 *rxd = (u8 *) t->rx_buf;
+ u8 data[10];
+ u32 cmd_regs[6];
+
+ if (!txd)
+ txd = data;
+
+ cdns_xspi->in_buffer = txd + 1;
+ cdns_xspi->out_buffer = txd + 1;
+
+ while (t->len) {
+
+ current_cycle_count = t->len > max_len ? max_len : t->len;
+
+ if (current_cycle_count < 10) {
+ cdns_xspi_prepare_generic(cs, txd, current_cycle_count,
+ false, cmd_regs);
+ cdns_xspi_trigger_command(cdns_xspi, cmd_regs);
+ if (cdns_xspi_stig_ready(cdns_xspi, true))
+ return -EIO;
+ } else {
+ cdns_xspi_prepare_generic(cs, txd, 1, true, cmd_regs);
+ cdns_xspi_trigger_command(cdns_xspi, cmd_regs);
+ cdns_xspi_prepare_transfer(cs, 1, current_cycle_count - 1,
+ cmd_regs);
+ cdns_xspi_trigger_command(cdns_xspi, cmd_regs);
+ if (cdns_xspi_sdma_ready(cdns_xspi, true))
+ return -EIO;
+ cdns_xspi_sdma_handle(cdns_xspi);
+ if (cdns_xspi_stig_ready(cdns_xspi, true))
+ return -EIO;
+
+ cdns_xspi->in_buffer += current_cycle_count;
+ cdns_xspi->out_buffer += current_cycle_count;
+ }
+
+ if (rxd) {
+ int j;
+
+ for (j = 0; j < current_cycle_count / 8; j++)
+ cdns_xspi_read_single_qword(cdns_xspi, &rxd);
+ cdns_xspi_finish_read(cdns_xspi, &rxd, current_cycle_count);
+ } else {
+ cdns_xspi->current_xfer_qword += current_cycle_count /
+ MRVL_XFER_QWORD_BYTECOUNT;
+ if (current_cycle_count % MRVL_XFER_QWORD_BYTECOUNT)
+ cdns_xspi->current_xfer_qword++;
+
+ cdns_xspi->current_xfer_qword %= MRVL_XFER_QWORD_COUNT;
+ }
+ cs_change = t->cs_change;
+ t->len -= current_cycle_count;
+ }
+ }
+
+ if (!cs_change) {
+ u32 xfer_control = readl(cdns_xspi->xferbase + MRVL_XFER_FUNC_CTRL);
+
+ xfer_control &= ~(MRVL_XFER_RECEIVE_ENABLE |
+ MRVL_XFER_SOFT_RESET);
+ writel(xfer_control, cdns_xspi->xferbase + MRVL_XFER_FUNC_CTRL);
+ cdns_xspi->xfer_in_progress = false;
+ }
+
+ m->status = 0;
+ spi_finalize_current_message(controller);
+
+ return 0;
+}
+
static int cdns_xspi_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
@@ -903,6 +1138,15 @@ static int cdns_xspi_probe(struct platform_device *pdev)
return PTR_ERR(cdns_xspi->auxbase);
}
+ if (cdns_xspi->mrvl_hw_overlay) {
+ cdns_xspi->xferbase = devm_platform_ioremap_resource(pdev, 3);
+ if (IS_ERR(cdns_xspi->xferbase)) {
+ dev_info(dev, "XFER register base not found, set it\n");
+ // For compatibility with older firmware
+ cdns_xspi->xferbase = cdns_xspi->iobase + 0x8000;
+ }
+ }
+
cdns_xspi->irq = platform_get_irq(pdev, 0);
if (cdns_xspi->irq < 0)
return -ENXIO;
@@ -917,6 +1161,7 @@ static int cdns_xspi_probe(struct platform_device *pdev)
if (drv_data->mrvl_hw_overlay) {
cdns_mrvl_xspi_setup_clock(cdns_xspi, MRVL_DEFAULT_CLK);
cdns_xspi_configure_phy(cdns_xspi);
+ host->transfer_one_message = cdns_xspi_transfer_one_message_b0;
}
cdns_xspi_print_phy_config(cdns_xspi);
--
2.43.0
