ARM: davinci: da8xx: add remoteproc support

Add remoteproc platform device for controlling the DSP
on da8xx. The patch uses CMA-based reservation of physical
memory block for DSP use. A new kernel command-line parameter
has been added to allow boot-time specification of the physical
memory block.

Signed-off-by: Robert Tivy <rtivy@ti.com>
[nsekhar@ti.com: edit commit message for readability and
style improvements]
Signed-off-by: Sekhar Nori <nsekhar@ti.com>

Documentation/kernel-parameters.txt

@@ -44,6 +44,7 @@ parameter is applicable:
 	AVR32	AVR32 architecture is enabled.
 	AX25	Appropriate AX.25 support is enabled.
 	BLACKFIN Blackfin architecture is enabled.
+	CMA	Contiguous Memory Area support is enabled.
 	DRM	Direct Rendering Management support is enabled.
 	DYNAMIC_DEBUG Build in debug messages and enable them at runtime
 	EDD	BIOS Enhanced Disk Drive Services (EDD) is enabled
@@ -2663,6 +2664,11 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
 			Useful for devices that are detected asynchronously
 			(e.g. USB and MMC devices).
 
+	rproc_mem=nn[KMG][@address]
+			[KNL,ARM,CMA] Remoteproc physical memory block.
+			Memory area to be used by remote processor image,
+			managed by CMA.
+
 	rw		[KNL] Mount root device read-write on boot
 
 	S		[KNL] Run init in single mode

arch/arm/mach-davinci/devices-da8xx.c

@@ -12,7 +12,7 @@
  */
 #include <linux/init.h>
 #include <linux/platform_device.h>
-#include <linux/dma-mapping.h>
+#include <linux/dma-contiguous.h>
 #include <linux/serial_8250.h>
 #include <linux/ahci_platform.h>
 #include <linux/clk.h>
@@ -714,6 +714,92 @@ int __init da850_register_mmcsd1(struct davinci_mmc_config *config)
 }
 #endif
 
+static struct resource da8xx_rproc_resources[] = {
+	{ /* DSP boot address */
+		.start		= DA8XX_SYSCFG0_BASE + DA8XX_HOST1CFG_REG,
+		.end		= DA8XX_SYSCFG0_BASE + DA8XX_HOST1CFG_REG + 3,
+		.flags		= IORESOURCE_MEM,
+	},
+	{ /* DSP interrupt registers */
+		.start		= DA8XX_SYSCFG0_BASE + DA8XX_CHIPSIG_REG,
+		.end		= DA8XX_SYSCFG0_BASE + DA8XX_CHIPSIG_REG + 7,
+		.flags		= IORESOURCE_MEM,
+	},
+	{ /* dsp irq */
+		.start		= IRQ_DA8XX_CHIPINT0,
+		.end		= IRQ_DA8XX_CHIPINT0,
+		.flags		= IORESOURCE_IRQ,
+	},
+};
+
+static struct platform_device da8xx_dsp = {
+	.name	= "davinci-rproc",
+	.dev	= {
+		.coherent_dma_mask	= DMA_BIT_MASK(32),
+	},
+	.num_resources	= ARRAY_SIZE(da8xx_rproc_resources),
+	.resource	= da8xx_rproc_resources,
+};
+
+#if IS_ENABLED(CONFIG_DA8XX_REMOTEPROC)
+
+static phys_addr_t rproc_base __initdata;
+static unsigned long rproc_size __initdata;
+
+static int __init early_rproc_mem(char *p)
+{
+	char *endp;
+
+	if (p == NULL)
+		return 0;
+
+	rproc_size = memparse(p, &endp);
+	if (*endp == '@')
+		rproc_base = memparse(endp + 1, NULL);
+
+	return 0;
+}
+early_param("rproc_mem", early_rproc_mem);
+
+void __init da8xx_rproc_reserve_cma(void)
+{
+	int ret;
+
+	if (!rproc_base || !rproc_size) {
+		pr_err("%s: 'rproc_mem=nn@address' badly specified\n"
+		       "    'nn' and 'address' must both be non-zero\n",
+		       __func__);
+
+		return;
+	}
+
+	pr_info("%s: reserving 0x%lx @ 0x%lx...\n",
+		__func__, rproc_size, (unsigned long)rproc_base);
+
+	ret = dma_declare_contiguous(&da8xx_dsp.dev, rproc_size, rproc_base, 0);
+	if (ret)
+		pr_err("%s: dma_declare_contiguous failed %d\n", __func__, ret);
+}
+
+#else
+
+void __init da8xx_rproc_reserve_cma(void)
+{
+}
+
+#endif
+
+int __init da8xx_register_rproc(void)
+{
+	int ret;
+
+	ret = platform_device_register(&da8xx_dsp);
+	if (ret)
+		pr_err("%s: can't register DSP device: %d\n", __func__, ret);
+
+	return ret;
+};
+
 static struct resource da8xx_rtc_resources[] = {
 	{
 		.start		= DA8XX_RTC_BASE,

arch/arm/mach-davinci/include/mach/da8xx.h

@@ -54,6 +54,8 @@ extern unsigned int da850_max_speed;
 #define DA8XX_SYSCFG0_BASE	(IO_PHYS + 0x14000)
 #define DA8XX_SYSCFG0_VIRT(x)	(da8xx_syscfg0_base + (x))
 #define DA8XX_JTAG_ID_REG	0x18
+#define DA8XX_HOST1CFG_REG	0x44
+#define DA8XX_CHIPSIG_REG	0x174
 #define DA8XX_CFGCHIP0_REG	0x17c
 #define DA8XX_CFGCHIP1_REG	0x180
 #define DA8XX_CFGCHIP2_REG	0x184
@@ -105,6 +107,8 @@ int __init da850_register_vpif_display
 int __init da850_register_vpif_capture
 			(struct vpif_capture_config *capture_config);
 void da8xx_restart(char mode, const char *cmd);
+void da8xx_rproc_reserve_cma(void);
+int da8xx_register_rproc(void);
 
 extern struct platform_device da8xx_serial_device;
 extern struct emac_platform_data da8xx_emac_pdata;