svn commit: r340458 - head/sys/arm/mv

[Luiz Otavio O Souza]

Author: loos
Date: Thu Nov 15 17:05:02 2018
New Revision: 340458
URL: https://svnweb.freebsd.org/changeset/base/340458

Log:
  Set the SPI clock speed and polarity on each transfer to catch up with
  recent changes in spibus and allow the use of different SPI modes on
  the same bus.
  
  Reported by:	ian
  Sponsored by:	Rubicon Communications, LLC (Netgate)

Modified:
  head/sys/arm/mv/mv_spi.c

Modified: head/sys/arm/mv/mv_spi.c
==============================================================================
--- head/sys/arm/mv/mv_spi.c	Thu Nov 15 16:42:59 2018	(r340457)
+++ head/sys/arm/mv/mv_spi.c	Thu Nov 15 17:05:02 2018	(r340458)
@@ -44,6 +44,8 @@ __FBSDID("$FreeBSD$");
 #include <dev/spibus/spi.h>
 #include <dev/spibus/spibusvar.h>
 
+#include <arm/mv/mvvar.h>
+
 #include "spibus_if.h"
 
 struct mv_spi_softc {
@@ -70,11 +72,23 @@ struct mv_spi_softc {
 #define	MV_SPI_UNLOCK(_sc)	mtx_unlock(&(_sc)->sc_mtx)
 
 #define	MV_SPI_CONTROL		0
+#define	MV_SPI_CTRL_CS_MASK		7
 #define	MV_SPI_CTRL_CS_SHIFT		2
 #define	MV_SPI_CTRL_SMEMREADY		(1 << 1)
 #define	MV_SPI_CTRL_CS_ACTIVE		(1 << 0)
 #define	MV_SPI_CONF		0x4
+#define	MV_SPI_CONF_MODE_SHIFT		12
+#define	MV_SPI_CONF_MODE_MASK		(3 << MV_SPI_CONF_MODE_SHIFT)
 #define	MV_SPI_CONF_BYTELEN		(1 << 5)
+#define	MV_SPI_CONF_CLOCK_SPR_MASK	0xf
+#define	MV_SPI_CONF_CLOCK_SPPR_MASK	1
+#define	MV_SPI_CONF_CLOCK_SPPR_SHIFT	4
+#define	MV_SPI_CONF_CLOCK_SPPRHI_MASK	3
+#define	MV_SPI_CONF_CLOCK_SPPRHI_SHIFT	6
+#define	MV_SPI_CONF_CLOCK_MASK						\
+    ((MV_SPI_CONF_CLOCK_SPPRHI_MASK << MV_SPI_CONF_CLOCK_SPPRHI_SHIFT) | \
+    (MV_SPI_CONF_CLOCK_SPPR_MASK << MV_SPI_CONF_CLOCK_SPPR_SHIFT) |	\
+    MV_SPI_CONF_CLOCK_SPR_MASK)
 #define	MV_SPI_DATAOUT		0x8
 #define	MV_SPI_DATAIN		0xc
 #define	MV_SPI_INTR_STAT	0x10
@@ -244,10 +258,27 @@ mv_spi_intr(void *arg)
 }
 
 static int
+mv_spi_psc_calc(uint32_t clock, uint32_t *spr, uint32_t *sppr)
+{
+	uint32_t divider, tclk;
+
+	tclk = get_tclk_armada38x();
+	for (*spr = 2; *spr <= 15; (*spr)++) {
+		for (*sppr = 0; *sppr <= 7; (*sppr)++) {
+			divider = *spr * (1 << *sppr);
+			if (tclk / divider <= clock)
+				return (0);
+		}
+	}
+
+	return (EINVAL);
+}
+
+static int
 mv_spi_transfer(device_t dev, device_t child, struct spi_command *cmd)
 {
 	struct mv_spi_softc *sc;
-	uint32_t cs, reg;
+	uint32_t clock, cs, mode, reg, spr, sppr;
 	int resid, timeout;
 
 	KASSERT(cmd->tx_cmd_sz == cmd->rx_cmd_sz,
@@ -255,9 +286,23 @@ mv_spi_transfer(device_t dev, device_t child, struct s
 	KASSERT(cmd->tx_data_sz == cmd->rx_data_sz,
 	    ("TX/RX data sizes should be equal"));
 
-	/* Get the proper chip select for this child. */
+	/* Get the proper chip select, mode and clock for this transfer. */
 	spibus_get_cs(child, &cs);
 	cs &= ~SPIBUS_CS_HIGH;
+	spibus_get_mode(child, &mode);
+	if (mode > 3) {
+		device_printf(dev,
+		    "Invalid mode %u requested by %s\n", mode,
+		    device_get_nameunit(child));
+		return (EINVAL);
+	}
+	spibus_get_clock(child, &clock);
+	if (clock == 0 || mv_spi_psc_calc(clock, &spr, &sppr) != 0) {
+		device_printf(dev,
+		    "Invalid clock %uHz requested by %s\n", clock,
+		    device_get_nameunit(child));
+		return (EINVAL);
+	}
 
 	sc = device_get_softc(dev);
 	MV_SPI_LOCK(sc);
@@ -275,7 +320,20 @@ mv_spi_transfer(device_t dev, device_t child, struct s
 	sc->sc_written = 0;
 	sc->sc_len = cmd->tx_cmd_sz + cmd->tx_data_sz;
 
-	MV_SPI_WRITE(sc, MV_SPI_CONTROL, cs << MV_SPI_CTRL_CS_SHIFT);
+	/* Set SPI Mode and Clock. */
+	reg = MV_SPI_READ(sc, MV_SPI_CONF);
+	reg &= ~(MV_SPI_CONF_MODE_MASK | MV_SPI_CONF_CLOCK_MASK);
+	reg |= mode << MV_SPI_CONF_MODE_SHIFT;
+	reg |= spr & MV_SPI_CONF_CLOCK_SPR_MASK;
+	reg |= (sppr & MV_SPI_CONF_CLOCK_SPPR_MASK) <<
+	    MV_SPI_CONF_CLOCK_SPPR_SHIFT;
+	reg |= (sppr & MV_SPI_CONF_CLOCK_SPPRHI_MASK) <<
+	    MV_SPI_CONF_CLOCK_SPPRHI_SHIFT;
+	MV_SPI_WRITE(sc, MV_SPI_CONTROL, reg);
+
+	/* Set CS number and assert CS. */
+	reg = (cs & MV_SPI_CTRL_CS_MASK) << MV_SPI_CTRL_CS_SHIFT;
+	MV_SPI_WRITE(sc, MV_SPI_CONTROL, reg);
 	reg = MV_SPI_READ(sc, MV_SPI_CONTROL);
 	MV_SPI_WRITE(sc, MV_SPI_CONTROL, reg | MV_SPI_CTRL_CS_ACTIVE);