staging/atomisp: Add support for the Intel IPU v2

This patch adds support for the Intel IPU v2 as found on Android and IoT
Baytrail-T and Baytrail-CR platforms (those with the IPU PCI mapped). You
will also need the firmware files from your device (Android usually puts
them into /etc) - or you can find them in the downloadable restore/upgrade
kits if you blew them away for some reason.

It may be possible to extend the driver to handle the BYT/T windows
platforms such as the ASUS T100TA. These platforms don't expose the IPU via
the PCI interface but via ACPI buried in the GPU description and with the
camera information somewhere unknown so would need a platform driver
interface adding to the codebase *IFF* the firmware works on such devices.

To get good results you also need a suitable support library such as
libxcam. The camera is intended to be driven from Android so it has a lot of
features that many desktop apps don't fully spport.

In theory all the pieces are there to build it with -DISP2401 and some
differing files to get CherryTrail/T support, but unifying the drivers
properlly is a work in progress.

The IPU driver represents the work of a lot of people within Intel over many
years. It's historical goal was portability rather than Linux upstream. Any
queries about the upstream aimed driver should be sent to me not to the
original authors.

Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 177 insertions, 0 deletions

diff --git a/drivers/staging/media/atomisp/pci/atomisp2/include/mmu/isp_mmu.h b/drivers/staging/media/atomisp/pci/atomisp2/include/mmu/isp_mmu.h
new file mode 100644
index 000000000000..790d5064b06b
--- /dev/null
+++ b/drivers/staging/media/atomisp/pci/atomisp2/include/mmu/isp_mmu.h
@@ -0,0 +1,177 @@
+/*
+ * Support for Medifield PNW Camera Imaging ISP subsystem.
+ *
+ * Copyright (c) 2010 Intel Corporation. All Rights Reserved.
+ *
+ * Copyright (c) 2010 Silicon Hive www.siliconhive.com.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License version
+ * 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+ * 02110-1301, USA.
+ *
+ */
+/*
+ * ISP MMU driver for classic two-level page tables
+ */
+#ifndef	__ISP_MMU_H__
+#define	__ISP_MMU_H__
+
+#include <linux/types.h>
+#include <linux/mutex.h>
+#include <linux/slab.h>
+
+/*
+ * do not change these values, the page size for ISP must be the
+ * same as kernel's page size.
+ */
+#define	ISP_PAGE_OFFSET		12
+#define	ISP_PAGE_SIZE		(1U << ISP_PAGE_OFFSET)
+#define	ISP_PAGE_MASK		(~(phys_addr_t)(ISP_PAGE_SIZE - 1))
+
+#define	ISP_L1PT_OFFSET		22
+#define	ISP_L1PT_MASK		(~((1U << ISP_L1PT_OFFSET) - 1))
+
+#define	ISP_L2PT_OFFSET		12
+#define	ISP_L2PT_MASK		(~(ISP_L1PT_MASK|(~(ISP_PAGE_MASK))))
+
+#define	ISP_L1PT_PTES		1024
+#define	ISP_L2PT_PTES		1024
+
+#define	ISP_PTR_TO_L1_IDX(x)	((((x) & ISP_L1PT_MASK)) \
+					>> ISP_L1PT_OFFSET)
+
+#define	ISP_PTR_TO_L2_IDX(x)	((((x) & ISP_L2PT_MASK)) \
+					>> ISP_L2PT_OFFSET)
+
+#define	ISP_PAGE_ALIGN(x)	(((x) + (ISP_PAGE_SIZE-1)) \
+					& ISP_PAGE_MASK)
+
+#define	ISP_PT_TO_VIRT(l1_idx, l2_idx, offset) do {\
+		((l1_idx) << ISP_L1PT_OFFSET) | \
+		((l2_idx) << ISP_L2PT_OFFSET) | \
+		(offset)\
+} while (0)
+
+#define	pgnr_to_size(pgnr)	((pgnr) << ISP_PAGE_OFFSET)
+#define	size_to_pgnr_ceil(size)	(((size) + (1 << ISP_PAGE_OFFSET) - 1)\
+						>> ISP_PAGE_OFFSET)
+#define	size_to_pgnr_bottom(size)	((size) >> ISP_PAGE_OFFSET)
+
+struct isp_mmu;
+
+struct isp_mmu_client {
+	/*
+	 * const value
+	 *
+	 * @name:
+	 *      driver name
+	 * @pte_valid_mask:
+	 *      should be 1 bit valid data, meaning the value should
+	 *      be power of 2.
+	 */
+	char *name;
+	unsigned int pte_valid_mask;
+	unsigned int null_pte;
+
+	/*
+	 * set/get page directory base address (physical address).
+	 *
+	 * must be provided.
+	 */
+	int (*set_pd_base) (struct isp_mmu *mmu,
+			phys_addr_t pd_base);
+	unsigned int (*get_pd_base) (struct isp_mmu *mmu, phys_addr_t pd_base);
+	/*
+	 * callback to flush tlb.
+	 *
+	 * tlb_flush_range will at least flush TLBs containing
+	 * address mapping from addr to addr + size.
+	 *
+	 * tlb_flush_all will flush all TLBs.
+	 *
+	 * tlb_flush_all is must be provided. if tlb_flush_range is
+	 * not valid, it will set to tlb_flush_all by default.
+	 */
+	void (*tlb_flush_range) (struct isp_mmu *mmu,
+				 unsigned int addr, unsigned int size);
+	void (*tlb_flush_all) (struct isp_mmu *mmu);
+	unsigned int (*phys_to_pte) (struct isp_mmu *mmu,
+				     phys_addr_t phys);
+	phys_addr_t (*pte_to_phys) (struct isp_mmu *mmu,
+				    unsigned int pte);
+
+};
+
+struct isp_mmu {
+	struct isp_mmu_client *driver;
+	unsigned int l1_pte;
+	int l2_pgt_refcount[ISP_L1PT_PTES];
+	phys_addr_t base_address;
+
+	struct mutex pt_mutex;
+#ifdef USE_KMEM_CACHE
+	struct kmem_cache *tbl_cache;
+#endif
+};
+
+/* flags for PDE and PTE */
+#define	ISP_PTE_VALID_MASK(mmu)	\
+	((mmu)->driver->pte_valid_mask)
+
+#define	ISP_PTE_VALID(mmu, pte)	\
+	((pte) & ISP_PTE_VALID_MASK(mmu))
+
+#define	NULL_PAGE	((phys_addr_t)(-1) & ISP_PAGE_MASK)
+#define	PAGE_VALID(page)	((page) != NULL_PAGE)
+
+/*
+ * init mmu with specific mmu driver.
+ */
+int isp_mmu_init(struct isp_mmu *mmu, struct isp_mmu_client *driver);
+/*
+ * cleanup all mmu related things.
+ */
+void isp_mmu_exit(struct isp_mmu *mmu);
+
+/*
+ * setup/remove address mapping for pgnr continous physical pages
+ * and isp_virt.
+ *
+ * map/unmap is mutex lock protected, and caller does not have
+ * to do lock/unlock operation.
+ *
+ * map/unmap will not flush tlb, and caller needs to deal with
+ * this itself.
+ */
+int isp_mmu_map(struct isp_mmu *mmu, unsigned int isp_virt,
+		phys_addr_t phys, unsigned int pgnr);
+
+void isp_mmu_unmap(struct isp_mmu *mmu, unsigned int isp_virt,
+		   unsigned int pgnr);
+
+static inline void isp_mmu_flush_tlb_all(struct isp_mmu *mmu)
+{
+	if (mmu->driver && mmu->driver->tlb_flush_all)
+		mmu->driver->tlb_flush_all(mmu);
+}
+
+#define isp_mmu_flush_tlb isp_mmu_flush_tlb_all
+
+static inline void isp_mmu_flush_tlb_range(struct isp_mmu *mmu,
+		unsigned int start, unsigned int size)
+{
+	if (mmu->driver && mmu->driver->tlb_flush_range)
+		mmu->driver->tlb_flush_range(mmu, start, size);
+}
+
+#endif /* ISP_MMU_H_ */