2 files changed, 63 insertions, 1 deletions

diff --git a/drivers/spi/spi-pl022.c b/drivers/spi/spi-pl022.c
index 7f13f3f7198b..d0741b2eabb4 100644
--- a/drivers/spi/spi-pl022.c
+++ b/drivers/spi/spi-pl022.c
@@ -82,6 +82,7 @@
 #define SSP_MIS(r)      (r + 0x01C)
 #define SSP_ICR(r)      (r + 0x020)
 #define SSP_DMACR(r)    (r + 0x024)
+#define SSP_CSR(r)      (r + 0x030) /* vendor extension */
 #define SSP_ITCR(r)     (r + 0x080)
 #define SSP_ITIP(r)     (r + 0x084)
 #define SSP_ITOP(r)     (r + 0x088)
@@ -198,6 +199,12 @@
 #define SSP_DMACR_MASK_TXDMAE           (0x1UL << 1)
 
 /*
+ * SSP Chip Select Control Register - SSP_CSR
+ * (vendor extension)
+ */
+#define SSP_CSR_CSVALUE_MASK            (0x1FUL << 0)
+
+/*
  * SSP Integration Test control Register - SSP_ITCR
  */
 #define SSP_ITCR_MASK_ITEN              (0x1UL << 0)
@@ -313,6 +320,7 @@ enum ssp_writing {
  * @extended_cr: 32 bit wide control register 0 with extra
  * features and extra features in CR1 as found in the ST variants
  * @pl023: supports a subset of the ST extensions called "PL023"
+ * @internal_cs_ctrl: supports chip select control register
  */
 struct vendor_data {
         int fifodepth;
@@ -321,6 +329,7 @@ struct vendor_data {
         bool extended_cr;
         bool pl023;
         bool loopback;
+        bool internal_cs_ctrl;
 };
 
 /**
@@ -440,9 +449,32 @@ static void null_cs_control(u32 command)
         pr_debug("pl022: dummy chip select control, CS=0x%x\n", command);
 }
 
+/**
+ * internal_cs_control - Control chip select signals via SSP_CSR.
+ * @pl022: SSP driver private data structure
+ * @command: select/delect the chip
+ *
+ * Used on controller with internal chip select control via SSP_CSR register
+ * (vendor extension). Each of the 5 LSB in the register controls one chip
+ * select signal.
+ */
+static void internal_cs_control(struct pl022 *pl022, u32 command)
+{
+        u32 tmp;
+
+        tmp = readw(SSP_CSR(pl022->virtbase));
+        if (command == SSP_CHIP_SELECT)
+                tmp &= ~BIT(pl022->cur_cs);
+        else
+                tmp |= BIT(pl022->cur_cs);
+        writew(tmp, SSP_CSR(pl022->virtbase));
+}
+
 static void pl022_cs_control(struct pl022 *pl022, u32 command)
 {
-        if (gpio_is_valid(pl022->cur_cs))
+        if (pl022->vendor->internal_cs_ctrl)
+                internal_cs_control(pl022, command);
+        else if (gpio_is_valid(pl022->cur_cs))
                 gpio_set_value(pl022->cur_cs, command);
         else
                 pl022->cur_chip->cs_control(command);
@@ -2122,6 +2154,9 @@ static int pl022_probe(struct amba_device *adev, const struct amba_id *id)
         if (platform_info->num_chipselect && platform_info->chipselects) {
                 for (i = 0; i < num_cs; i++)
                         pl022->chipselects[i] = platform_info->chipselects[i];
+        } else if (pl022->vendor->internal_cs_ctrl) {
+                for (i = 0; i < num_cs; i++)
+                        pl022->chipselects[i] = i;
         } else if (IS_ENABLED(CONFIG_OF)) {
                 for (i = 0; i < num_cs; i++) {
                         int cs_gpio = of_get_named_gpio(np, "cs-gpios", i);
@@ -2352,6 +2387,7 @@ static struct vendor_data vendor_arm = {
         .extended_cr = false,
         .pl023 = false,
         .loopback = true,
+        .internal_cs_ctrl = false,
 };
 
 static struct vendor_data vendor_st = {
@@ -2361,6 +2397,7 @@ static struct vendor_data vendor_st = {
         .extended_cr = true,
         .pl023 = false,
         .loopback = true,
+        .internal_cs_ctrl = false,
 };
 
 static struct vendor_data vendor_st_pl023 = {
@@ -2370,6 +2407,17 @@ static struct vendor_data vendor_st_pl023 = {
         .extended_cr = true,
         .pl023 = true,
         .loopback = false,
+        .internal_cs_ctrl = false,
+};
+
+static struct vendor_data vendor_lsi = {
+        .fifodepth = 8,
+        .max_bpw = 16,
+        .unidir = false,
+        .extended_cr = false,
+        .pl023 = false,
+        .loopback = true,
+        .internal_cs_ctrl = true,
 };
 
 static struct amba_id pl022_ids[] = {
@@ -2403,6 +2451,15 @@ static struct amba_id pl022_ids[] = {
                 .mask   = 0xffffffff,
                 .data   = &vendor_st_pl023,
         },
+        {
+                /*
+                 * PL022 variant that has a chip select control register whih
+                 * allows control of 5 output signals nCS[0:4].
+                 */
+                .id     = 0x000b6022,
+                .mask   = 0x000fffff,
+                .data   = &vendor_lsi,
+        },
         { 0, 0 },
 };
 
diff --git a/include/linux/amba/bus.h b/include/linux/amba/bus.h
index fdd7e1b61f60..c324f5700d1a 100644
--- a/include/linux/amba/bus.h
+++ b/include/linux/amba/bus.h
@@ -44,10 +44,15 @@ struct amba_driver {
         const struct amba_id    *id_table;
 };
 
+/*
+ * Constants for the designer field of the Peripheral ID register. When bit 7
+ * is set to '1', bits [6:0] should be the JEP106 manufacturer identity code.
+ */
 enum amba_vendor {
         AMBA_VENDOR_ARM = 0x41,
         AMBA_VENDOR_ST = 0x80,
         AMBA_VENDOR_QCOM = 0x51,
+        AMBA_VENDOR_LSI = 0xb6,
 };
 
 extern struct bus_type amba_bustype;