@@ -8,7 +8,15 @@ Required properties:
- "marvell,armada-380-spi", for the Armada 38x SoCs
- "marvell,armada-390-spi", for the Armada 39x SoCs
- "marvell,armada-xp-spi", for the Armada XP SoCs
-- reg : offset and length of the register set for the device
+- reg : offset and length of the register set for the device.
+ This property can optionally have additional entries to configure
+ the SPI direct access mode that some of the Marvell SoCs support
+ additionally to the normal indirect access (PIO) mode. The values
+ for the MBus "target" and "attribute" are defined in the Marvell
+ SoC "Functional Specifications" Manual in the chapter "Marvell
+ Core Processor Address Decoding".
+ The eight register sets following the control registers refer to
+ chip-select lines 0 through 7 respectively.
- cell-index : Which of multiple SPI controllers is this.
Optional properties:
- interrupts : Is currently not used.
@@ -23,3 +31,42 @@ Example:
interrupts = <23>;
status = "disabled";
};
+
+Example with SPI direct mode support (optionally):
+ spi0: spi@10600 {
+ compatible = "marvell,orion-spi";
+ #address-cells = <1>;
+ #size-cells = <0>;
+ cell-index = <0>;
+ reg = <MBUS_ID(0xf0, 0x01) 0x10600 0x28>, /* control */
+ <MBUS_ID(0x01, 0x1e) 0 0xffffffff>, /* CS0 */
+ <MBUS_ID(0x01, 0x5e) 0 0xffffffff>, /* CS1 */
+ <MBUS_ID(0x01, 0x9e) 0 0xffffffff>, /* CS2 */
+ <MBUS_ID(0x01, 0xde) 0 0xffffffff>, /* CS3 */
+ <MBUS_ID(0x01, 0x1f) 0 0xffffffff>, /* CS4 */
+ <MBUS_ID(0x01, 0x5f) 0 0xffffffff>, /* CS5 */
+ <MBUS_ID(0x01, 0x9f) 0 0xffffffff>, /* CS6 */
+ <MBUS_ID(0x01, 0xdf) 0 0xffffffff>; /* CS7 */
+ interrupts = <23>;
+ status = "disabled";
+ };
+
+To enable the direct mode, the board specific 'ranges' property in the
+'soc' node needs to add the entries for the desired SPI controllers
+and its chip-selects that are used in the direct mode instead of PIO
+mode. Here an example for this (SPI controller 0, device 1 and SPI
+controller 1, device 2 are used in direct mode. All other SPI device
+are used in the default indirect (PIO) mode):
+ soc {
+ /*
+ * Enable the SPI direct access by configuring an entry
+ * here in the board-specific ranges property
+ */
+ ranges = <MBUS_ID(0xf0, 0x01) 0 0 0xf1000000 0x100000>, /* internal regs */
+ <MBUS_ID(0x01, 0x1d) 0 0 0xfff00000 0x100000>, /* BootROM */
+ <MBUS_ID(0x01, 0x5e) 0 0 0xf1100000 0x10000>, /* SPI0-DEV1 */
+ <MBUS_ID(0x01, 0x9a) 0 0 0xf1110000 0x10000>; /* SPI1-DEV2 */
+
+For further information on the MBus bindings, please see the MBus
+DT documentation:
+Documentation/devicetree/bindings/bus/mvebu-mbus.txt
@@ -18,6 +18,7 @@
#include <linux/module.h>
#include <linux/pm_runtime.h>
#include <linux/of.h>
+#include <linux/of_address.h>
#include <linux/of_device.h>
#include <linux/clk.h>
#include <linux/sizes.h>
@@ -43,6 +44,9 @@
#define ORION_SPI_INT_CAUSE_REG 0x10
#define ORION_SPI_TIMING_PARAMS_REG 0x18
+/* Register for the "Direct Mode" */
+#define SPI_DIRECT_WRITE_CONFIG_REG 0x20
+
#define ORION_SPI_TMISO_SAMPLE_MASK (0x3 << 6)
#define ORION_SPI_TMISO_SAMPLE_1 (1 << 6)
#define ORION_SPI_TMISO_SAMPLE_2 (2 << 6)
@@ -78,11 +82,18 @@ struct orion_spi_dev {
bool is_errata_50mhz_ac;
};
+struct orion_direct_acc {
+ void __iomem *vaddr;
+ u32 size;
+};
+
struct orion_spi {
struct spi_master *master;
void __iomem *base;
struct clk *clk;
const struct orion_spi_dev *devdata;
+
+ struct orion_direct_acc direct_access[ORION_NUM_CHIPSELECTS];
};
static inline void __iomem *spi_reg(struct orion_spi *orion_spi, u32 reg)
@@ -372,10 +383,38 @@ orion_spi_write_read(struct spi_device *spi, struct spi_transfer *xfer)
{
unsigned int count;
int word_len;
+ struct orion_spi *orion_spi;
+ int cs = spi->chip_select;
word_len = spi->bits_per_word;
count = xfer->len;
+ orion_spi = spi_master_get_devdata(spi->master);
+
+ /*
+ * Use SPI direct write mode if base address is available. Otherwise
+ * fall back to PIO mode for this transfer.
+ */
+ if ((orion_spi->direct_access[cs].vaddr) && (xfer->tx_buf) &&
+ (word_len == 8)) {
+ unsigned int cnt = count / 4;
+ unsigned int rem = count % 4;
+
+ /*
+ * Send the TX-data to the SPI device via the direct
+ * mapped address window
+ */
+ writesl(orion_spi->direct_access[cs].vaddr, xfer->tx_buf, cnt);
+ if (rem) {
+ u32 *buf = (u32 *)xfer->tx_buf;
+
+ writesb(orion_spi->direct_access[cs].vaddr, &buf[cnt],
+ rem);
+ }
+
+ return count;
+ }
+
if (word_len == 8) {
const u8 *tx = xfer->tx_buf;
u8 *rx = xfer->rx_buf;
@@ -425,6 +464,10 @@ static int orion_spi_reset(struct orion_spi *orion_spi)
{
/* Verify that the CS is deasserted */
orion_spi_clrbits(orion_spi, ORION_SPI_IF_CTRL_REG, 0x1);
+
+ /* Don't deassert CS between the direct mapped SPI transfers */
+ writel(0, spi_reg(orion_spi, SPI_DIRECT_WRITE_CONFIG_REG));
+
return 0;
}
@@ -504,6 +547,7 @@ static int orion_spi_probe(struct platform_device *pdev)
struct resource *r;
unsigned long tclk_hz;
int status = 0;
+ struct device_node *np;
master = spi_alloc_master(&pdev->dev, sizeof(*spi));
if (master == NULL) {
@@ -576,6 +620,49 @@ static int orion_spi_probe(struct platform_device *pdev)
goto out_rel_clk;
}
+ /* Scan all SPI devices of this controller for direct mapped devices */
+ for_each_available_child_of_node(pdev->dev.of_node, np) {
+ u32 cs;
+
+ /* Get chip-select number from the "reg" property */
+ status = of_property_read_u32(np, "reg", &cs);
+ if (status) {
+ dev_err(&pdev->dev,
+ "%s has no valid 'reg' property (%d)\n",
+ np->full_name, status);
+ status = 0;
+ continue;
+ }
+
+ /*
+ * Check if an address is configured for this SPI device. If
+ * not, the MBus mapping via the 'ranges' property in the 'soc'
+ * node is not configured and this device should not use the
+ * direct mode. In this case, just continue with the next
+ * device.
+ */
+ status = of_address_to_resource(pdev->dev.of_node, cs + 1, r);
+ if (status)
+ continue;
+
+ /*
+ * Only map one page for direct access. This is enough for the
+ * simple TX transfer which only writes to the first word.
+ * This needs to get extended for the direct SPI-NOR / SPI-NAND
+ * support, once this gets implemented.
+ */
+ spi->direct_access[cs].vaddr = devm_ioremap(&pdev->dev,
+ r->start,
+ PAGE_SIZE);
+ if (IS_ERR(spi->direct_access[cs].vaddr)) {
+ status = PTR_ERR(spi->direct_access[cs].vaddr);
+ goto out_rel_clk;
+ }
+ spi->direct_access[cs].size = PAGE_SIZE;
+
+ dev_info(&pdev->dev, "CS%d configured for direct access\n", cs);
+ }
+
pm_runtime_set_active(&pdev->dev);
pm_runtime_use_autosuspend(&pdev->dev);
pm_runtime_set_autosuspend_delay(&pdev->dev, SPI_AUTOSUSPEND_TIMEOUT);