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path: root/drivers/spi/spi-zynq-qspi.c
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Diffstat (limited to 'drivers/spi/spi-zynq-qspi.c')
-rw-r--r--drivers/spi/spi-zynq-qspi.c84
1 files changed, 50 insertions, 34 deletions
diff --git a/drivers/spi/spi-zynq-qspi.c b/drivers/spi/spi-zynq-qspi.c
index 5cf6993ddce5..17641157354d 100644
--- a/drivers/spi/spi-zynq-qspi.c
+++ b/drivers/spi/spi-zynq-qspi.c
@@ -7,7 +7,6 @@
#include <linux/clk.h>
#include <linux/delay.h>
-#include <linux/gpio.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/module.h>
@@ -51,7 +50,6 @@
#define ZYNQ_QSPI_CONFIG_BDRATE_MASK GENMASK(5, 3) /* Baud Rate Mask */
#define ZYNQ_QSPI_CONFIG_CPHA_MASK BIT(2) /* Clock Phase Control */
#define ZYNQ_QSPI_CONFIG_CPOL_MASK BIT(1) /* Clock Polarity Control */
-#define ZYNQ_QSPI_CONFIG_SSCTRL_MASK BIT(10) /* Slave Select Mask */
#define ZYNQ_QSPI_CONFIG_FWIDTH_MASK GENMASK(7, 6) /* FIFO width */
#define ZYNQ_QSPI_CONFIG_MSTREN_MASK BIT(0) /* Master Mode */
@@ -61,9 +59,9 @@
* These are the values used in the calculation of baud rate divisor and
* setting the slave select.
*/
-#define ZYNQ_QSPI_BAUD_DIV_MAX GENMASK(2, 0) /* Baud rate maximum */
-#define ZYNQ_QSPI_BAUD_DIV_SHIFT 3 /* Baud rate divisor shift in CR */
-#define ZYNQ_QSPI_SS_SHIFT 10 /* Slave Select field shift in CR */
+#define ZYNQ_QSPI_CONFIG_BAUD_DIV_MAX GENMASK(2, 0) /* Baud rate maximum */
+#define ZYNQ_QSPI_CONFIG_BAUD_DIV_SHIFT 3 /* Baud rate divisor shift */
+#define ZYNQ_QSPI_CONFIG_PCS BIT(10) /* Peripheral Chip Select */
/*
* QSPI Interrupt Registers bit Masks
@@ -99,9 +97,9 @@
* It is named Linear Configuration but it controls other modes when not in
* linear mode also.
*/
-#define ZYNQ_QSPI_LCFG_TWO_MEM_MASK BIT(30) /* LQSPI Two memories Mask */
-#define ZYNQ_QSPI_LCFG_SEP_BUS_MASK BIT(29) /* LQSPI Separate bus Mask */
-#define ZYNQ_QSPI_LCFG_U_PAGE_MASK BIT(28) /* LQSPI Upper Page Mask */
+#define ZYNQ_QSPI_LCFG_TWO_MEM BIT(30) /* LQSPI Two memories */
+#define ZYNQ_QSPI_LCFG_SEP_BUS BIT(29) /* LQSPI Separate bus */
+#define ZYNQ_QSPI_LCFG_U_PAGE BIT(28) /* LQSPI Upper Page */
#define ZYNQ_QSPI_LCFG_DUMMY_SHIFT 8
@@ -116,8 +114,8 @@
*/
#define ZYNQ_QSPI_MODEBITS (SPI_CPOL | SPI_CPHA)
-/* Default number of chip selects */
-#define ZYNQ_QSPI_DEFAULT_NUM_CS 1
+/* Maximum number of chip selects */
+#define ZYNQ_QSPI_MAX_NUM_CS 2
/**
* struct zynq_qspi - Defines qspi driver instance
@@ -161,6 +159,7 @@ static inline void zynq_qspi_write(struct zynq_qspi *xqspi, u32 offset,
/**
* zynq_qspi_init_hw - Initialize the hardware
* @xqspi: Pointer to the zynq_qspi structure
+ * @num_cs: Number of connected CS (to enable dual memories if needed)
*
* The default settings of the QSPI controller's configurable parameters on
* reset are
@@ -178,7 +177,7 @@ static inline void zynq_qspi_write(struct zynq_qspi *xqspi, u32 offset,
* - Set the little endian mode of TX FIFO and
* - Enable the QSPI controller
*/
-static void zynq_qspi_init_hw(struct zynq_qspi *xqspi)
+static void zynq_qspi_init_hw(struct zynq_qspi *xqspi, unsigned int num_cs)
{
u32 config_reg;
@@ -186,7 +185,12 @@ static void zynq_qspi_init_hw(struct zynq_qspi *xqspi)
zynq_qspi_write(xqspi, ZYNQ_QSPI_IDIS_OFFSET, ZYNQ_QSPI_IXR_ALL_MASK);
/* Disable linear mode as the boot loader may have used it */
- zynq_qspi_write(xqspi, ZYNQ_QSPI_LINEAR_CFG_OFFSET, 0);
+ config_reg = 0;
+ /* At the same time, enable dual mode if more than 1 CS is available */
+ if (num_cs > 1)
+ config_reg |= ZYNQ_QSPI_LCFG_TWO_MEM;
+
+ zynq_qspi_write(xqspi, ZYNQ_QSPI_LINEAR_CFG_OFFSET, config_reg);
/* Clear the RX FIFO */
while (zynq_qspi_read(xqspi, ZYNQ_QSPI_STATUS_OFFSET) &
@@ -284,21 +288,28 @@ static void zynq_qspi_txfifo_op(struct zynq_qspi *xqspi, unsigned int size)
*/
static void zynq_qspi_chipselect(struct spi_device *spi, bool assert)
{
- struct spi_controller *ctrl = spi->master;
- struct zynq_qspi *xqspi = spi_controller_get_devdata(ctrl);
+ struct spi_controller *ctlr = spi->master;
+ struct zynq_qspi *xqspi = spi_controller_get_devdata(ctlr);
u32 config_reg;
- config_reg = zynq_qspi_read(xqspi, ZYNQ_QSPI_CONFIG_OFFSET);
- if (assert) {
- /* Select the slave */
- config_reg &= ~ZYNQ_QSPI_CONFIG_SSCTRL_MASK;
- config_reg |= (((~(BIT(spi->chip_select))) <<
- ZYNQ_QSPI_SS_SHIFT) &
- ZYNQ_QSPI_CONFIG_SSCTRL_MASK);
- } else {
- config_reg |= ZYNQ_QSPI_CONFIG_SSCTRL_MASK;
+ /* Select the lower (CS0) or upper (CS1) memory */
+ if (ctlr->num_chipselect > 1) {
+ config_reg = zynq_qspi_read(xqspi, ZYNQ_QSPI_LINEAR_CFG_OFFSET);
+ if (!spi->chip_select)
+ config_reg &= ~ZYNQ_QSPI_LCFG_U_PAGE;
+ else
+ config_reg |= ZYNQ_QSPI_LCFG_U_PAGE;
+
+ zynq_qspi_write(xqspi, ZYNQ_QSPI_LINEAR_CFG_OFFSET, config_reg);
}
+ /* Ground the line to assert the CS */
+ config_reg = zynq_qspi_read(xqspi, ZYNQ_QSPI_CONFIG_OFFSET);
+ if (assert)
+ config_reg &= ~ZYNQ_QSPI_CONFIG_PCS;
+ else
+ config_reg |= ZYNQ_QSPI_CONFIG_PCS;
+
zynq_qspi_write(xqspi, ZYNQ_QSPI_CONFIG_OFFSET, config_reg);
}
@@ -332,7 +343,7 @@ static int zynq_qspi_config_op(struct zynq_qspi *xqspi, struct spi_device *spi)
* ----------------
* 111 - divide by 256
*/
- while ((baud_rate_val < ZYNQ_QSPI_BAUD_DIV_MAX) &&
+ while ((baud_rate_val < ZYNQ_QSPI_CONFIG_BAUD_DIV_MAX) &&
(clk_get_rate(xqspi->refclk) / (2 << baud_rate_val)) >
spi->max_speed_hz)
baud_rate_val++;
@@ -348,7 +359,7 @@ static int zynq_qspi_config_op(struct zynq_qspi *xqspi, struct spi_device *spi)
config_reg |= ZYNQ_QSPI_CONFIG_CPOL_MASK;
config_reg &= ~ZYNQ_QSPI_CONFIG_BDRATE_MASK;
- config_reg |= (baud_rate_val << ZYNQ_QSPI_BAUD_DIV_SHIFT);
+ config_reg |= (baud_rate_val << ZYNQ_QSPI_CONFIG_BAUD_DIV_SHIFT);
zynq_qspi_write(xqspi, ZYNQ_QSPI_CONFIG_OFFSET, config_reg);
return 0;
@@ -365,10 +376,10 @@ static int zynq_qspi_config_op(struct zynq_qspi *xqspi, struct spi_device *spi)
*/
static int zynq_qspi_setup_op(struct spi_device *spi)
{
- struct spi_controller *ctrl = spi->master;
- struct zynq_qspi *qspi = spi_controller_get_devdata(ctrl);
+ struct spi_controller *ctlr = spi->master;
+ struct zynq_qspi *qspi = spi_controller_get_devdata(ctlr);
- if (ctrl->busy)
+ if (ctlr->busy)
return -EBUSY;
clk_enable(qspi->refclk);
@@ -663,9 +674,6 @@ static int zynq_qspi_probe(struct platform_device *pdev)
goto clk_dis_pclk;
}
- /* QSPI controller initializations */
- zynq_qspi_init_hw(xqspi);
-
xqspi->irq = platform_get_irq(pdev, 0);
if (xqspi->irq <= 0) {
ret = -ENXIO;
@@ -681,10 +689,14 @@ static int zynq_qspi_probe(struct platform_device *pdev)
ret = of_property_read_u32(np, "num-cs",
&num_cs);
- if (ret < 0)
- ctlr->num_chipselect = ZYNQ_QSPI_DEFAULT_NUM_CS;
- else
+ if (ret < 0) {
+ ctlr->num_chipselect = 1;
+ } else if (num_cs > ZYNQ_QSPI_MAX_NUM_CS) {
+ dev_err(&pdev->dev, "only 2 chip selects are available\n");
+ goto remove_master;
+ } else {
ctlr->num_chipselect = num_cs;
+ }
ctlr->mode_bits = SPI_RX_DUAL | SPI_RX_QUAD |
SPI_TX_DUAL | SPI_TX_QUAD;
@@ -692,6 +704,10 @@ static int zynq_qspi_probe(struct platform_device *pdev)
ctlr->setup = zynq_qspi_setup_op;
ctlr->max_speed_hz = clk_get_rate(xqspi->refclk) / 2;
ctlr->dev.of_node = np;
+
+ /* QSPI controller initializations */
+ zynq_qspi_init_hw(xqspi, ctlr->num_chipselect);
+
ret = devm_spi_register_controller(&pdev->dev, ctlr);
if (ret) {
dev_err(&pdev->dev, "spi_register_master failed\n");