[ARM] 4754/1: [AT91] SSC library support

Core support of the Atmel SSC library for all Atmel AT91 processors.

Based on David Brownell's initial patch for the AT91RM9200.

Signed-off-by: Andrew Victor <linux@maxim.org.za>
Acked-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

1 files changed, 79 insertions, 0 deletions

diff --git a/arch/arm/mach-at91/at91sam9260_devices.c b/arch/arm/mach-at91/at91sam9260_devices.c
index c34fde362ad4..2e3db137bc49 100644
--- a/arch/arm/mach-at91/at91sam9260_devices.c
+++ b/arch/arm/mach-at91/at91sam9260_devices.c
@@ -607,6 +607,85 @@ void __init at91_init_leds(u8 cpu_led, u8 timer_led) {}
 
 
 /* --------------------------------------------------------------------
+ *  SSC -- Synchronous Serial Controller
+ * -------------------------------------------------------------------- */
+
+#if defined(CONFIG_ATMEL_SSC) || defined(CONFIG_ATMEL_SSC_MODULE)
+static u64 ssc_dmamask = DMA_BIT_MASK(32);
+
+static struct resource ssc_resources[] = {
+        [0] = {
+                .start  = AT91SAM9260_BASE_SSC,
+                .end    = AT91SAM9260_BASE_SSC + SZ_16K - 1,
+                .flags  = IORESOURCE_MEM,
+        },
+        [1] = {
+                .start  = AT91SAM9260_ID_SSC,
+                .end    = AT91SAM9260_ID_SSC,
+                .flags  = IORESOURCE_IRQ,
+        },
+};
+
+static struct platform_device at91sam9260_ssc_device = {
+        .name   = "ssc",
+        .id     = 0,
+        .dev    = {
+                .dma_mask               = &ssc_dmamask,
+                .coherent_dma_mask      = DMA_BIT_MASK(32),
+        },
+        .resource       = ssc_resources,
+        .num_resources  = ARRAY_SIZE(ssc_resources),
+};
+
+static inline void configure_ssc_pins(unsigned pins)
+{
+        if (pins & ATMEL_SSC_TF)
+                at91_set_A_periph(AT91_PIN_PB17, 1);
+        if (pins & ATMEL_SSC_TK)
+                at91_set_A_periph(AT91_PIN_PB16, 1);
+        if (pins & ATMEL_SSC_TD)
+                at91_set_A_periph(AT91_PIN_PB18, 1);
+        if (pins & ATMEL_SSC_RD)
+                at91_set_A_periph(AT91_PIN_PB19, 1);
+        if (pins & ATMEL_SSC_RK)
+                at91_set_A_periph(AT91_PIN_PB20, 1);
+        if (pins & ATMEL_SSC_RF)
+                at91_set_A_periph(AT91_PIN_PB21, 1);
+}
+
+/*
+ * SSC controllers are accessed through library code, instead of any
+ * kind of all-singing/all-dancing driver.  For example one could be
+ * used by a particular I2S audio codec's driver, while another one
+ * on the same system might be used by a custom data capture driver.
+ */
+void __init at91_add_device_ssc(unsigned id, unsigned pins)
+{
+        struct platform_device *pdev;
+
+        /*
+         * NOTE: caller is responsible for passing information matching
+         * "pins" to whatever will be using each particular controller.
+         */
+        switch (id) {
+        case AT91SAM9260_ID_SSC:
+                pdev = &at91sam9260_ssc_device;
+                configure_ssc_pins(pins);
+                at91_clock_associate("ssc_clk", &pdev->dev, "pclk");
+                break;
+        default:
+                return;
+        }
+
+        platform_device_register(pdev);
+}
+
+#else
+void __init at91_add_device_ssc(unsigned id, unsigned pins) {}
+#endif
+
+
+/* --------------------------------------------------------------------
  *  UART
  * -------------------------------------------------------------------- */
 #if defined(CONFIG_SERIAL_ATMEL)