[PATCH 09/14] spi: rspi: Add support for RSPI on RZ/A1H

From: Geert Uytterhoeven
Date: Fri Jan 24 2014 - 03:48:22 EST

From: Geert Uytterhoeven <geert+renesas@xxxxxxxxxxxxxx>

Add support for the RSPI variant in the RZ/A1H (r7s72100) SoC.

Main differences with RSPI on SH are:
- Lack of TX only mode, hence we always have to use full duplex
transfers,
- The Data Register must be accessed used 8-bit operations.

RSPI on RZ is matched using the new "rspi-rz" platform device name.

Signed-off-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxxxxxxx>
---
drivers/spi/spi-rspi.c | 101 +++++++++++++++++++++++++++++++++++++++++++-----
1 file changed, 92 insertions(+), 9 deletions(-)

diff --git a/drivers/spi/spi-rspi.c b/drivers/spi/spi-rspi.c
index d2ade5e09f58..0c7556978d2e 100644
--- a/drivers/spi/spi-rspi.c
+++ b/drivers/spi/spi-rspi.c
@@ -47,7 +47,7 @@
#define RSPI_SPCKD 0x0c /* Clock Delay Register */
#define RSPI_SSLND 0x0d /* Slave Select Negation Delay Register */
#define RSPI_SPND 0x0e /* Next-Access Delay Register */
-#define RSPI_SPCR2 0x0f /* Control Register 2 */
+#define RSPI_SPCR2 0x0f /* Control Register 2 (SH only) */
#define RSPI_SPCMD0 0x10 /* Command Register 0 */
#define RSPI_SPCMD1 0x12 /* Command Register 1 */
#define RSPI_SPCMD2 0x14 /* Command Register 2 */
@@ -56,10 +56,12 @@
#define RSPI_SPCMD5 0x1a /* Command Register 5 */
#define RSPI_SPCMD6 0x1c /* Command Register 6 */
#define RSPI_SPCMD7 0x1e /* Command Register 7 */
+
+/* RSPI on RZ only */
#define RSPI_SPBFCR 0x20 /* Buffer Control Register */
#define RSPI_SPBFDR 0x22 /* Buffer Data Count Setting Register */

-/*qspi only */
+/* QSPI only */
#define QSPI_SPBFCR 0x18 /* Buffer Control Register */
#define QSPI_SPBDCR 0x1a /* Buffer Data Count Register */
#define QSPI_SPBMUL0 0x1c /* Transfer Data Length Multiplier Setting Register 0 */
@@ -102,7 +104,7 @@
#define SPSR_PERF 0x08 /* Parity Error Flag */
#define SPSR_MODF 0x04 /* Mode Fault Error Flag */
#define SPSR_IDLNF 0x02 /* RSPI Idle Flag */
-#define SPSR_OVRF 0x01 /* Overrun Error Flag */
+#define SPSR_OVRF 0x01 /* Overrun Error Flag (RSPI only) */

/* SPSCR - Sequence Control Register */
#define SPSCR_SPSLN_MASK 0x07 /* Sequence Length Specification */
@@ -119,13 +121,13 @@
#define SPDCR_SPLWORD SPDCR_SPLW1
#define SPDCR_SPLBYTE SPDCR_SPLW0
#define SPDCR_SPLW 0x20 /* Access Width Specification (SH) */
-#define SPDCR_SPRDTD 0x10 /* Receive Transmit Data Select */
+#define SPDCR_SPRDTD 0x10 /* Receive Transmit Data Select (SH) */
#define SPDCR_SLSEL1 0x08
#define SPDCR_SLSEL0 0x04
-#define SPDCR_SLSEL_MASK 0x0c /* SSL1 Output Select */
+#define SPDCR_SLSEL_MASK 0x0c /* SSL1 Output Select (SH) */
#define SPDCR_SPFC1 0x02
#define SPDCR_SPFC0 0x01
-#define SPDCR_SPFC_MASK 0x03 /* Frame Count Setting (1-4) */
+#define SPDCR_SPFC_MASK 0x03 /* Frame Count Setting (1-4) (SH) */

/* SPCKD - Clock Delay Register */
#define SPCKD_SCKDL_MASK 0x07 /* Clock Delay Setting (1-8) */
@@ -168,8 +170,8 @@
#define SPCMD_CPHA 0x0001 /* Clock Phase Setting */

/* SPBFCR - Buffer Control Register */
-#define SPBFCR_TXRST 0x80 /* Transmit Buffer Data Reset (qspi only) */
-#define SPBFCR_RXRST 0x40 /* Receive Buffer Data Reset (qspi only) */
+#define SPBFCR_TXRST 0x80 /* Transmit Buffer Data Reset */
+#define SPBFCR_RXRST 0x40 /* Receive Buffer Data Reset */
#define SPBFCR_TXTRG_MASK 0x30 /* Transmit Buffer Data Triggering Number */
#define SPBFCR_RXTRG_MASK 0x07 /* Receive Buffer Data Triggering Number */

@@ -244,7 +246,7 @@ struct spi_ops {
};

/*
- * functions for RSPI
+ * functions for RSPI on legacy SH
*/
static int rspi_set_config_register(struct rspi_data *rspi, int access_size)
{
@@ -280,6 +282,39 @@ static int rspi_set_config_register(struct rspi_data *rspi, int access_size)
}

/*
+ * functions for RSPI on RZ
+ */
+static int rspi_rz_set_config_register(struct rspi_data *rspi, int access_size)
+{
+ int spbr;
+
+ /* Sets output mode */
+ rspi_write8(rspi, 0x00, RSPI_SPPCR);
+
+ /* Sets transfer bit rate */
+ spbr = clk_get_rate(rspi->clk) / (2 * rspi->max_speed_hz) - 1;
+ rspi_write8(rspi, clamp(spbr, 0, 255), RSPI_SPBR);
+
+ /* Disable dummy transmission, set byte access */
+ rspi_write8(rspi, SPDCR_SPLBYTE, RSPI_SPDCR);
+ rspi->byte_access = 1;
+
+ /* Sets RSPCK, SSL, next-access delay value */
+ rspi_write8(rspi, 0x00, RSPI_SPCKD);
+ rspi_write8(rspi, 0x00, RSPI_SSLND);
+ rspi_write8(rspi, 0x00, RSPI_SPND);
+
+ /* Sets SPCMD */
+ rspi->spcmd |= SPCMD_SPB_8_TO_16(access_size);
+ rspi_write16(rspi, rspi->spcmd, RSPI_SPCMD0);
+
+ /* Sets RSPI mode */
+ rspi_write8(rspi, SPCR_MSTR, RSPI_SPCR);
+
+ return 0;
+}
+
+/*
* functions for QSPI
*/
static int qspi_set_config_register(struct rspi_data *rspi, int access_size)
@@ -520,6 +555,13 @@ static void rspi_receive_init(const struct rspi_data *rspi)
RSPI_SPSR);
}

+static void rspi_rz_receive_init(const struct rspi_data *rspi)
+{
+ rspi_receive_init(rspi);
+ rspi_write8(rspi, SPBFCR_TXRST | SPBFCR_RXRST, RSPI_SPBFCR);
+ rspi_write8(rspi, 0, RSPI_SPBFCR);
+}
+
static void qspi_receive_init(const struct rspi_data *rspi)
{
u8 spsr;
@@ -706,6 +748,41 @@ static int rspi_transfer_one(struct spi_master *master, struct spi_device *spi,
return 0;
}

+static int rspi_rz_transfer_out_in(struct rspi_data *rspi,
+ struct spi_transfer *xfer)
+{
+ int remain = xfer->len, ret;
+ const u8 *tx_buf = xfer->tx_buf;
+ u8 *rx_buf = xfer->rx_buf;
+ u8 data;
+
+ rspi_rz_receive_init(rspi);
+
+ while (remain > 0) {
+ data = tx_buf ? *tx_buf++ : DUMMY_DATA;
+ ret = rspi_data_out_in(rspi, data);
+ if (ret < 0)
+ return ret;
+ if (rx_buf)
+ *rx_buf++ = ret;
+ remain--;
+ }
+
+ /* Wait for the last transmission */
+ rspi_wait_for_interrupt(rspi, SPSR_SPTEF, SPCR_SPTIE);
+
+ return 0;
+}
+
+static int rspi_rz_transfer_one(struct spi_master *master,
+ struct spi_device *spi,
+ struct spi_transfer *xfer)
+{
+ struct rspi_data *rspi = spi_master_get_devdata(master);
+
+ return rspi_rz_transfer_out_in(rspi, xfer);
+}
+
static int qspi_transfer_out_in(struct rspi_data *rspi,
struct spi_transfer *xfer)
{
@@ -1041,6 +1118,11 @@ static struct spi_ops rspi_ops = {
.transfer_one = rspi_transfer_one,
};

+static struct spi_ops rspi_rz_ops = {
+ .set_config_register = rspi_rz_set_config_register,
+ .transfer_one = rspi_rz_transfer_one,
+};
+
static struct spi_ops qspi_ops = {
.set_config_register = qspi_set_config_register,
.transfer_one = qspi_transfer_one,
@@ -1048,6 +1130,7 @@ static struct spi_ops qspi_ops = {

static struct platform_device_id spi_driver_ids[] = {
{ "rspi", (kernel_ulong_t)&rspi_ops },
+ { "rspi-rz", (kernel_ulong_t)&rspi_rz_ops },
{ "qspi", (kernel_ulong_t)&qspi_ops },
{},
};
--
1.7.9.5

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