spi: spi-zynqmp-gqspi: Add tap delay support for GQSPI controller on Versal platform

Add tap delay support for GQSPI controller on Versal platform.

Signed-off-by: Naga Sureshkumar Relli <nagasure@xilinx.com>
Signed-off-by: Michal Simek <michal.simek@amd.com>
Signed-off-by: Amit Kumar Mahapatra <amit.kumar-mahapatra@amd.com>
Link: https://lore.kernel.org/r/20221011062040.12116-8-amit.kumar-mahapatra@amd.com
Signed-off-by: Mark Brown <broonie@kernel.org>

diff --git a/drivers/spi/spi-zynqmp-gqspi.c b/drivers/spi/spi-zynqmp-gqspi.c
index c11736d96f33438e5b26128791a4de56fd792bd8..95ff15665d448bf4d735539115259d768d404af0 100644 (file)
--- a/drivers/spi/spi-zynqmp-gqspi.c
+++ b/drivers/spi/spi-zynqmp-gqspi.c
@@ -16,6 +16,7 @@
 #include <linux/module.h>
 #include <linux/of_irq.h>
 #include <linux/of_address.h>
+#include <linux/of_device.h>
 #include <linux/platform_device.h>
 #include <linux/pm_runtime.h>
 #include <linux/spi/spi.h>
@@ -34,6 +35,7 @@
 #define GQSPI_RXD_OFST                 0x00000120
 #define GQSPI_TX_THRESHOLD_OFST                0x00000128
 #define GQSPI_RX_THRESHOLD_OFST                0x0000012C
+#define IOU_TAPDLY_BYPASS_OFST         0x0000003C
 #define GQSPI_LPBK_DLY_ADJ_OFST                0x00000138
 #define GQSPI_GEN_FIFO_OFST            0x00000140
 #define GQSPI_SEL_OFST                 0x00000144
@@ -141,6 +143,13 @@
 #define GQSPI_USE_DATA_DLY_SHIFT       31
 #define GQSPI_DATA_DLY_ADJ_VALUE       0x2
 #define GQSPI_DATA_DLY_ADJ_SHIFT       28
+#define GQSPI_LPBK_DLY_ADJ_DLY_1       0x1
+#define GQSPI_LPBK_DLY_ADJ_DLY_1_SHIFT 0x3
+#define TAP_DLY_BYPASS_LQSPI_RX_VALUE  0x1
+#define TAP_DLY_BYPASS_LQSPI_RX_SHIFT  0x2
+
+/* set to differentiate versal from zynqmp, 1=versal, 0=zynqmp */
+#define QSPI_QUIRK_HAS_TAPDELAY                BIT(0)
 
 #define GQSPI_FREQ_37_5MHZ     37500000
 #define GQSPI_FREQ_40MHZ       40000000
@@ -150,6 +159,14 @@
 #define SPI_AUTOSUSPEND_TIMEOUT                3000
 enum mode_type {GQSPI_MODE_IO, GQSPI_MODE_DMA};
 
+/**
+ * struct qspi_platform_data - zynqmp qspi platform data structure
+ * @quirks:    Flags is used to identify the platform
+ */
+struct qspi_platform_data {
+       u32 quirks;
+};
+
 /**
  * struct zynqmp_qspi - Defines qspi driver instance
  * @ctlr:              Pointer to the spi controller information
@@ -171,6 +188,7 @@ enum mode_type {GQSPI_MODE_IO, GQSPI_MODE_DMA};
  * @data_completion:   completion structure
  * @op_lock:           Operational lock
  * @speed_hz:          Current SPI bus clock speed in hz
+ * @has_tapdelay:      Used for tapdelay register available in qspi
  */
 struct zynqmp_qspi {
        struct spi_controller *ctlr;
@@ -192,6 +210,7 @@ struct zynqmp_qspi {
        struct completion data_completion;
        struct mutex op_lock;
        u32 speed_hz;
+       bool has_tapdelay;
 };
 
 /**
@@ -271,25 +290,44 @@ static void zynqmp_gqspi_selectslave(struct zynqmp_qspi *instanceptr,
  */
 static void zynqmp_qspi_set_tapdelay(struct zynqmp_qspi *xqspi, u32 baudrateval)
 {
-       u32 lpbkdlyadj = 0, datadlyadj = 0, clk_rate;
+       u32 tapdlybypass = 0, lpbkdlyadj = 0, datadlyadj = 0, clk_rate;
        u32 reqhz = 0;
 
        clk_rate = clk_get_rate(xqspi->refclk);
        reqhz = (clk_rate / (GQSPI_BAUD_DIV_SHIFT << baudrateval));
 
-       if (reqhz <= GQSPI_FREQ_40MHZ) {
-               zynqmp_pm_set_tapdelay_bypass(PM_TAPDELAY_QSPI,
-                                             PM_TAPDELAY_BYPASS_ENABLE);
-       } else if (reqhz <= GQSPI_FREQ_100MHZ) {
-               zynqmp_pm_set_tapdelay_bypass(PM_TAPDELAY_QSPI,
-                                             PM_TAPDELAY_BYPASS_ENABLE);
-               lpbkdlyadj |= (GQSPI_LPBK_DLY_ADJ_USE_LPBK_MASK);
-               datadlyadj |= ((GQSPI_USE_DATA_DLY <<
-                               GQSPI_USE_DATA_DLY_SHIFT) |
-                              (GQSPI_DATA_DLY_ADJ_VALUE <<
-                               GQSPI_DATA_DLY_ADJ_SHIFT));
-       } else if (reqhz <= GQSPI_FREQ_150MHZ) {
-               lpbkdlyadj |= GQSPI_LPBK_DLY_ADJ_USE_LPBK_MASK;
+       if (!xqspi->has_tapdelay) {
+               if (reqhz <= GQSPI_FREQ_40MHZ) {
+                       zynqmp_pm_set_tapdelay_bypass(PM_TAPDELAY_QSPI,
+                                                     PM_TAPDELAY_BYPASS_ENABLE);
+               } else if (reqhz <= GQSPI_FREQ_100MHZ) {
+                       zynqmp_pm_set_tapdelay_bypass(PM_TAPDELAY_QSPI,
+                                                     PM_TAPDELAY_BYPASS_ENABLE);
+                       lpbkdlyadj |= (GQSPI_LPBK_DLY_ADJ_USE_LPBK_MASK);
+                       datadlyadj |= ((GQSPI_USE_DATA_DLY <<
+                                       GQSPI_USE_DATA_DLY_SHIFT)
+                                       | (GQSPI_DATA_DLY_ADJ_VALUE <<
+                                               GQSPI_DATA_DLY_ADJ_SHIFT));
+               } else if (reqhz <= GQSPI_FREQ_150MHZ) {
+                       lpbkdlyadj |= GQSPI_LPBK_DLY_ADJ_USE_LPBK_MASK;
+               }
+       } else {
+               if (reqhz <= GQSPI_FREQ_37_5MHZ) {
+                       tapdlybypass |= (TAP_DLY_BYPASS_LQSPI_RX_VALUE <<
+                                       TAP_DLY_BYPASS_LQSPI_RX_SHIFT);
+               } else if (reqhz <= GQSPI_FREQ_100MHZ) {
+                       tapdlybypass |= (TAP_DLY_BYPASS_LQSPI_RX_VALUE <<
+                                       TAP_DLY_BYPASS_LQSPI_RX_SHIFT);
+                       lpbkdlyadj |= (GQSPI_LPBK_DLY_ADJ_USE_LPBK_MASK);
+                       datadlyadj |= (GQSPI_USE_DATA_DLY <<
+                                       GQSPI_USE_DATA_DLY_SHIFT);
+               } else if (reqhz <= GQSPI_FREQ_150MHZ) {
+                       lpbkdlyadj |= (GQSPI_LPBK_DLY_ADJ_USE_LPBK_MASK
+                                      | (GQSPI_LPBK_DLY_ADJ_DLY_1 <<
+                                              GQSPI_LPBK_DLY_ADJ_DLY_1_SHIFT));
+               }
+               zynqmp_gqspi_write(xqspi,
+                                  IOU_TAPDLY_BYPASS_OFST, tapdlybypass);
        }
        zynqmp_gqspi_write(xqspi, GQSPI_LPBK_DLY_ADJ_OFST, lpbkdlyadj);
        zynqmp_gqspi_write(xqspi, GQSPI_DATA_DLY_ADJ_OFST, datadlyadj);
@@ -1156,6 +1194,16 @@ static const struct dev_pm_ops zynqmp_qspi_dev_pm_ops = {
        SET_SYSTEM_SLEEP_PM_OPS(zynqmp_qspi_suspend, zynqmp_qspi_resume)
 };
 
+static const struct qspi_platform_data versal_qspi_def = {
+       .quirks = QSPI_QUIRK_HAS_TAPDELAY,
+};
+
+static const struct of_device_id zynqmp_qspi_of_match[] = {
+       { .compatible = "xlnx,zynqmp-qspi-1.0"},
+       { .compatible = "xlnx,versal-qspi-1.0", .data = &versal_qspi_def },
+       { /* End of table */ }
+};
+
 static const struct spi_controller_mem_ops zynqmp_qspi_mem_ops = {
        .exec_op = zynqmp_qspi_exec_op,
 };
@@ -1176,6 +1224,7 @@ static int zynqmp_qspi_probe(struct platform_device *pdev)
        struct device *dev = &pdev->dev;
        struct device_node *np = dev->of_node;
        u32 num_cs;
+       const struct qspi_platform_data *p_data;
 
        ctlr = spi_alloc_master(&pdev->dev, sizeof(*xqspi));
        if (!ctlr)
@@ -1186,6 +1235,10 @@ static int zynqmp_qspi_probe(struct platform_device *pdev)
        xqspi->ctlr = ctlr;
        platform_set_drvdata(pdev, xqspi);
 
+       p_data = of_device_get_match_data(&pdev->dev);
+       if (p_data && (p_data->quirks & QSPI_QUIRK_HAS_TAPDELAY))
+               xqspi->has_tapdelay = true;
+
        xqspi->regs = devm_platform_ioremap_resource(pdev, 0);
        if (IS_ERR(xqspi->regs)) {
                ret = PTR_ERR(xqspi->regs);
@@ -1324,11 +1377,6 @@ static int zynqmp_qspi_remove(struct platform_device *pdev)
        return 0;
 }
 
-static const struct of_device_id zynqmp_qspi_of_match[] = {
-       { .compatible = "xlnx,zynqmp-qspi-1.0", },
-       { /* End of table */ }
-};
-
 MODULE_DEVICE_TABLE(of, zynqmp_qspi_of_match);
 
 static struct platform_driver zynqmp_qspi_driver = {