mtd: st_spi_fsm: Supply framework for device requests

The FSM hardware works by setting a predetermined sequence of register
writes. Rather than open coding them inside each functional block we're
going to define them in a series of formatted 'sequence structures'.
This patch provides the framework which shall be used for every action.

Acked-by Angus Clark <angus.clark@st.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

diff --git a/drivers/mtd/devices/st_spi_fsm.c b/drivers/mtd/devices/st_spi_fsm.c
index 7048ea75bf275f2c296cedba3f59a1be005e8798..5e22c8688197f5ce2cd39ef31c0d013e671099ae 100644 (file)
--- a/drivers/mtd/devices/st_spi_fsm.c
+++ b/drivers/mtd/devices/st_spi_fsm.c
@@ -194,6 +194,8 @@
 
 #define STFSM_FLASH_SAFE_FREQ  10000000UL                         /* 10 MHz */
 
+#define STFSM_MAX_WAIT_SEQ_MS  1000     /* FSM execution time */
+
 struct stfsm {
        struct device           *dev;
        void __iomem            *base;
@@ -204,6 +206,24 @@ struct stfsm {
        uint32_t                fifo_dir_delay;
 };
 
+struct stfsm_seq {
+       uint32_t data_size;
+       uint32_t addr1;
+       uint32_t addr2;
+       uint32_t addr_cfg;
+       uint32_t seq_opc[5];
+       uint32_t mode;
+       uint32_t dummy;
+       uint32_t status;
+       uint8_t  seq[16];
+       uint32_t seq_cfg;
+} __packed __aligned(4);
+
+static inline int stfsm_is_idle(struct stfsm *fsm)
+{
+       return readl(fsm->base + SPI_FAST_SEQ_STA) & 0x10;
+}
+
 static inline uint32_t stfsm_fifo_available(struct stfsm *fsm)
 {
        return (readl(fsm->base + SPI_FAST_SEQ_STA) >> 5) & 0x7f;
@@ -225,6 +245,42 @@ static void stfsm_clear_fifo(struct stfsm *fsm)
        }
 }
 
+static inline void stfsm_load_seq(struct stfsm *fsm,
+                                 const struct stfsm_seq *seq)
+{
+       void __iomem *dst = fsm->base + SPI_FAST_SEQ_TRANSFER_SIZE;
+       const uint32_t *src = (const uint32_t *)seq;
+       int words = sizeof(*seq) / sizeof(*src);
+
+       BUG_ON(!stfsm_is_idle(fsm));
+
+       while (words--) {
+               writel(*src, dst);
+               src++;
+               dst += 4;
+       }
+}
+
+static void stfsm_wait_seq(struct stfsm *fsm)
+{
+       unsigned long deadline;
+       int timeout = 0;
+
+       deadline = jiffies + msecs_to_jiffies(STFSM_MAX_WAIT_SEQ_MS);
+
+       while (!timeout) {
+               if (time_after_eq(jiffies, deadline))
+                       timeout = 1;
+
+               if (stfsm_is_idle(fsm))
+                       return;
+
+               cond_resched();
+       }
+
+       dev_err(fsm->dev, "timeout on sequence completion\n");
+}
+
 static int stfsm_set_mode(struct stfsm *fsm, uint32_t mode)
 {
        int ret, timeout = 10;