Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755919AbaGIMim (ORCPT ); Wed, 9 Jul 2014 08:38:42 -0400 Received: from comal.ext.ti.com ([198.47.26.152]:36391 "EHLO comal.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755782AbaGIMij (ORCPT ); Wed, 9 Jul 2014 08:38:39 -0400 From: Roger Quadros To: , CC: , , , , , , , , , Roger Quadros Subject: [RFC PATCH 05/10] OMAP: GPMC: Introduce APIs for accessing Prefetch/Write-post engine Date: Wed, 9 Jul 2014 15:37:25 +0300 Message-ID: <1404909450-11970-6-git-send-email-rogerq@ti.com> X-Mailer: git-send-email 1.8.3.2 In-Reply-To: <1404909450-11970-1-git-send-email-rogerq@ti.com> References: <1404909450-11970-1-git-send-email-rogerq@ti.com> MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Even though the Prefetch engine is meant for exclusive use by the OMAP NAND controller, itst registers belong to the GPMC controller's register space. Introduce 4 APIs to access the Prefetch/Write-post engine. int omap_gpmc_prefetch_start(int cs, int fifo_th, bool dma, u32 count, int is_write); int omap_gpmc_prefetch_stop(int cs); u32 omap_gpmc_get_prefetch_count(void); u32 omap_gpmc_get_prefetch_fifo_count(void); Signed-off-by: Roger Quadros --- arch/arm/mach-omap2/gpmc.c | 134 +++++++++++++++++++++++++++++++++++++++++ include/linux/omap-gpmc-nand.h | 30 +++++++++ 2 files changed, 164 insertions(+) diff --git a/arch/arm/mach-omap2/gpmc.c b/arch/arm/mach-omap2/gpmc.c index 92bbada..43e2a9d 100644 --- a/arch/arm/mach-omap2/gpmc.c +++ b/arch/arm/mach-omap2/gpmc.c @@ -33,6 +33,7 @@ #include #include #include +#include #include @@ -114,6 +115,20 @@ #define GPMC_NR_WAITPINS 4 +/* GPMC Prefetch/Write-post Engine */ +#define GPMC_PREFETCH_CONFIG1_ENABLE_PREFETCH BIT(7) +#define GPMC_PREFETCH_CONFIG1_DMAMODE BIT(2) +#define GPMC_PREFETCH_CONFIG1_ACCESSMODE BIT(0) +#define GPMC_PREFETCH_CONFIG1_CS_MASK GENMASK(26, 24) +#define GPMC_PREFETCH_CONFIG1_CS_SHIFT 24 +#define GPMC_PREFETCH_CONFIG1_FIFOTH_MASK GENMASK(14, 8) +#define GPMC_PREFETCH_CONFIG1_FIFOTH_SHIFT 8 + +#define GPMC_PREFETCH_CONTROL_START BIT(0) + +#define GPMC_PREFETCH_STATUS_COUNT(val) (val & 0x00003fff) +#define GPMC_PREFETCH_STATUS_FIFO_CNT(val) ((val >> 24) & 0x7F) + /* XXX: Only NAND irq has been considered,currently these are the only ones used */ #define GPMC_NR_IRQ 2 @@ -1971,3 +1986,122 @@ void omap_gpmc_write_reg(int cs, enum omap_gpmc_reg reg, u32 val) break; } } + +/** + * omap_gpmc_prefetch_start - configures and starts the prefetch engine + * + * @cs: cs (chip select) number + * @fifo_th: fifo threshold to be used for read/ write + * @dma: dma mode enable (1) or disable (0) + * @count: number of bytes to be transferred + * @is_write: prefetch read(0) or write post(1) mode + * + * As there is a single prefetch engine that must be shared between + * chip selects containing NAND flashes, the function returns -EBUSY if + * the engine is already in use. Returns 0 on success. + */ +int omap_gpmc_prefetch_start(int cs, int fifo_th, bool dma, + u32 count, int is_write) +{ + u32 val; + + if (!gpmc_dev) + return -ENODEV; + + if (cs >= gpmc_cs_num) + return -EINVAL; + + if (fifo_th > GPMC_PREFETCH_FIFOTHRESHOLD_MAX) + return -EINVAL; + + /* Check if engine is already in use */ + if (gpmc_read_reg(GPMC_PREFETCH_CONTROL)) + return -EBUSY; + + /* Set the amount of bytes to be prefetched */ + gpmc_write_reg(GPMC_PREFETCH_CONFIG2, count); + + /* Set dma/mpu mode, the prefetch read / post write and + * enable the engine. Set which cs is has requested for. + */ + val = ((cs << GPMC_PREFETCH_CONFIG1_CS_SHIFT) | + GPMC_PREFETCH_CONFIG1_ENABLE_PREFETCH | + (GPMC_PREFETCH_CONFIG1_ACCESSMODE & is_write)); + + val |= (fifo_th << GPMC_PREFETCH_CONFIG1_FIFOTH_SHIFT) & + GPMC_PREFETCH_CONFIG1_FIFOTH_MASK; + + if (dma) + val |= GPMC_PREFETCH_CONFIG1_DMAMODE; + + gpmc_write_reg(GPMC_PREFETCH_CONFIG1, val); + + /* Start the prefetch engine */ + gpmc_write_reg(GPMC_PREFETCH_CONTROL, GPMC_PREFETCH_CONTROL_START); + + return 0; +} + +/** + * omap_gpmc_prefetch_stop - stops and disables the prefetch engine + * + * @cs: Chip select number + */ +int omap_gpmc_prefetch_stop(int cs) +{ + u32 config1; + + if (!gpmc_dev) + return -ENODEV; + + if (cs >= gpmc_cs_num) + return -EINVAL; + + /* check if the same module/cs is trying to reset */ + config1 = gpmc_read_reg(GPMC_PREFETCH_CONFIG1); + config1 &= GPMC_PREFETCH_CONFIG1_CS_MASK; + + if ((config1 >> GPMC_PREFETCH_CONFIG1_CS_SHIFT) != cs) + return -EINVAL; + + /* Stop the engine */ + gpmc_write_reg(GPMC_PREFETCH_CONTROL, 0); + + /* Reset/disable the engine */ + gpmc_write_reg(GPMC_PREFETCH_CONFIG1, 0); + + return 0; +} + +/** + * omap_gpmc_get_prefetch_count - Returns the number of bytes remaining to be + * read or written by the prefetch/write-post engine + */ +u32 omap_gpmc_get_prefetch_count(void) +{ + u32 count; + + if (!gpmc_dev) + return 0; + + count = gpmc_read_reg(GPMC_PREFETCH_STATUS); + count = GPMC_PREFETCH_STATUS_COUNT(count); + return count; +} + +/** + * omap_gpmc_get_prefetch_fifo_count - Returns the number of bytes available + * to be read from the FIFO or free bytes available to be written to the FIFO + * by the CPU + */ +u32 omap_gpmc_get_prefetch_fifo_count(void) +{ + u32 count; + + if (!gpmc_dev) + return 0; + + count = gpmc_read_reg(GPMC_PREFETCH_STATUS); + count = GPMC_PREFETCH_STATUS_FIFO_CNT(count); + return count; +} diff --git a/include/linux/omap-gpmc-nand.h b/include/linux/omap-gpmc-nand.h index dcb2abe..c445d89 100644 --- a/include/linux/omap-gpmc-nand.h +++ b/include/linux/omap-gpmc-nand.h @@ -26,6 +26,12 @@ enum omap_gpmc_reg { #ifdef CONFIG_ARCH_OMAP2PLUS u32 omap_gpmc_read_reg(int cs, enum omap_gpmc_reg reg); void omap_gpmc_write_reg(int cs, enum omap_gpmc_reg reg, u32 val); + +int omap_gpmc_prefetch_start(int cs, int fifo_th, bool dma, + u32 count, int is_write); +int omap_gpmc_prefetch_stop(int cs); +u32 omap_gpmc_get_prefetch_count(void); +u32 omap_gpmc_get_prefetch_fifo_count(void); #else static inline u32 omap_gpmc_read_reg(int cs, enum omap_gpmc_reg reg) { @@ -35,6 +41,30 @@ static inline u32 omap_gpmc_read_reg(int cs, enum omap_gpmc_reg reg) static inline void omap_gpmc_write_reg(int cs, enum omap_gpmc_reg reg, u32 val) { } + +static inline int omap_gpmc_prefetch_start(int cs, int fifo_th, bool dma, + u32 count, int is_write) +{ + return -ENOSYS; +} + +static inline int omap_gpmc_prefetch_stop(int cs) +{ + return -ENOSYS; +} + +static inline u32 omap_gpmc_get_prefetch_count(void) +{ + return 0; +} + +static inline u32 omap_gpmc_get_prefetch_fifo_count(void) +{ + return 0; +} #endif +/* Prefetch/Write-post Engine */ +#define GPMC_PREFETCH_FIFOTHRESHOLD_MAX 0x40 + #endif /* _GPMC_OMAP_H_ */ -- 1.8.3.2 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/