spi: sprd: Simplify the transfer function

We can move the hardware spinlock protection into the ADI read/write
functions to simplify the sprd_adi_transfer_one() function. Moreover
this optimization can also help to access PMIC without considering
the hardware spinlock using sprd_adi_read/write() functions.

Signed-off-by: Baolin Wang <baolin.wang@linaro.org>
Signed-off-by: Mark Brown <broonie@kernel.org>

diff --git a/drivers/spi/spi-sprd-adi.c b/drivers/spi/spi-sprd-adi.c
index 5993bdbf79e46e9aa2b4bde4ab29729cf623f90a..74bbd045aac02f41002aebc87a9891a2aa383d6e 100644 (file)
--- a/drivers/spi/spi-sprd-adi.c
+++ b/drivers/spi/spi-sprd-adi.c
@@ -123,7 +123,17 @@ static int sprd_adi_fifo_is_full(struct sprd_adi *sadi)
 static int sprd_adi_read(struct sprd_adi *sadi, u32 reg_paddr, u32 *read_val)
 {
        int read_timeout = ADI_READ_TIMEOUT;
+       unsigned long flags;
        u32 val, rd_addr;
+       int ret;
+
+       ret = hwspin_lock_timeout_irqsave(sadi->hwlock,
+                                         ADI_HWSPINLOCK_TIMEOUT,
+                                         &flags);
+       if (ret) {
+               dev_err(sadi->dev, "get the hw lock failed\n");
+               return ret;
+       }
 
        /*
         * Set the physical register address need to read into RD_CMD register,
@@ -147,7 +157,8 @@ static int sprd_adi_read(struct sprd_adi *sadi, u32 reg_paddr, u32 *read_val)
 
        if (read_timeout == 0) {
                dev_err(sadi->dev, "ADI read timeout\n");
-               return -EBUSY;
+               ret = -EBUSY;
+               goto out;
        }
 
        /*
@@ -161,21 +172,35 @@ static int sprd_adi_read(struct sprd_adi *sadi, u32 reg_paddr, u32 *read_val)
        if (rd_addr != (reg_paddr & REG_ADDR_LOW_MASK)) {
                dev_err(sadi->dev, "read error, reg addr = 0x%x, val = 0x%x\n",
                        reg_paddr, val);
-               return -EIO;
+               ret = -EIO;
+               goto out;
        }
 
        *read_val = val & RD_VALUE_MASK;
-       return 0;
+
+out:
+       hwspin_unlock_irqrestore(sadi->hwlock, &flags);
+       return ret;
 }
 
-static int sprd_adi_write(struct sprd_adi *sadi, unsigned long reg, u32 val)
+static int sprd_adi_write(struct sprd_adi *sadi, u32 reg_paddr, u32 val)
 {
+       unsigned long reg = sprd_adi_to_vaddr(sadi, reg_paddr);
        u32 timeout = ADI_FIFO_DRAIN_TIMEOUT;
+       unsigned long flags;
        int ret;
 
+       ret = hwspin_lock_timeout_irqsave(sadi->hwlock,
+                                         ADI_HWSPINLOCK_TIMEOUT,
+                                         &flags);
+       if (ret) {
+               dev_err(sadi->dev, "get the hw lock failed\n");
+               return ret;
+       }
+
        ret = sprd_adi_drain_fifo(sadi);
        if (ret < 0)
-               return ret;
+               goto out;
 
        /*
         * we should wait for write fifo is empty before writing data to PMIC
@@ -192,10 +217,12 @@ static int sprd_adi_write(struct sprd_adi *sadi, unsigned long reg, u32 val)
 
        if (timeout == 0) {
                dev_err(sadi->dev, "write fifo is full\n");
-               return -EBUSY;
+               ret = -EBUSY;
        }
 
-       return 0;
+out:
+       hwspin_unlock_irqrestore(sadi->hwlock, &flags);
+       return ret;
 }
 
 static int sprd_adi_transfer_one(struct spi_controller *ctlr,
@@ -203,7 +230,6 @@ static int sprd_adi_transfer_one(struct spi_controller *ctlr,
                                 struct spi_transfer *t)
 {
        struct sprd_adi *sadi = spi_controller_get_devdata(ctlr);
-       unsigned long flags, virt_reg;
        u32 phy_reg, val;
        int ret;
 
@@ -214,16 +240,7 @@ static int sprd_adi_transfer_one(struct spi_controller *ctlr,
                if (ret)
                        return ret;
 
-               ret = hwspin_lock_timeout_irqsave(sadi->hwlock,
-                                                 ADI_HWSPINLOCK_TIMEOUT,
-                                                 &flags);
-               if (ret) {
-                       dev_err(sadi->dev, "get the hw lock failed\n");
-                       return ret;
-               }
-
                ret = sprd_adi_read(sadi, phy_reg, &val);
-               hwspin_unlock_irqrestore(sadi->hwlock, &flags);
                if (ret)
                        return ret;
 
@@ -241,19 +258,8 @@ static int sprd_adi_transfer_one(struct spi_controller *ctlr,
                if (ret)
                        return ret;
 
-               virt_reg = sprd_adi_to_vaddr(sadi, phy_reg);
                val = *p;
-
-               ret = hwspin_lock_timeout_irqsave(sadi->hwlock,
-                                                 ADI_HWSPINLOCK_TIMEOUT,
-                                                 &flags);
-               if (ret) {
-                       dev_err(sadi->dev, "get the hw lock failed\n");
-                       return ret;
-               }
-
-               ret = sprd_adi_write(sadi, virt_reg, val);
-               hwspin_unlock_irqrestore(sadi->hwlock, &flags);
+               ret = sprd_adi_write(sadi, phy_reg, val);
                if (ret)
                        return ret;
        } else {