spi: rzv2m-csi: Improve data types, casting and alignment

"unsigned int" is more appropriate than "int" for the members
of "struct rzv2m_csi_priv".
Using void* rather than u8* for txbuf and rxbuf allows for
the removal of some type casting.
Remove the unnecessary casting of "data" to "struct rzv2m_csi_priv*"
in function "rzv2m_csi_irq_handler".
Also, members "bytes_per_word" and "errors" introduce gaps
in the structure.
Adjust "struct rzv2m_csi_priv" and its members usage accordingly.

Signed-off-by: Fabrizio Castro <fabrizio.castro.jz@renesas.com>
Suggested-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/20230718192453.543549-3-fabrizio.castro.jz@renesas.com
Signed-off-by: Mark Brown <broonie@kernel.org>

diff --git a/drivers/spi/spi-rzv2m-csi.c b/drivers/spi/spi-rzv2m-csi.c
index faf5898bc3e01daa4b76187fb48428f8b5efad65..4dbb8c185a8a0709ae0982306dc39ca810e7ae87 100644 (file)
--- a/drivers/spi/spi-rzv2m-csi.c
+++ b/drivers/spi/spi-rzv2m-csi.c
@@ -63,8 +63,8 @@
 /* CSI_FIFOTRG */
 #define CSI_FIFOTRG_R_TRG       GENMASK(2, 0)
 
-#define CSI_FIFO_SIZE_BYTES    32
-#define CSI_FIFO_HALF_SIZE     16
+#define CSI_FIFO_SIZE_BYTES    32U
+#define CSI_FIFO_HALF_SIZE     16U
 #define CSI_EN_DIS_TIMEOUT_US  100
 /*
  * Clock "csiclk" gets divided by 2 * CSI_CLKSEL_CKS in order to generate the
@@ -86,16 +86,16 @@ struct rzv2m_csi_priv {
        struct clk *pclk;
        struct device *dev;
        struct spi_controller *controller;
-       const u8 *txbuf;
-       u8 *rxbuf;
-       int buffer_len;
-       int bytes_sent;
-       int bytes_received;
-       int bytes_to_transfer;
-       int words_to_transfer;
-       unsigned char bytes_per_word;
+       const void *txbuf;
+       void *rxbuf;
+       unsigned int buffer_len;
+       unsigned int bytes_sent;
+       unsigned int bytes_received;
+       unsigned int bytes_to_transfer;
+       unsigned int words_to_transfer;
+       unsigned int bytes_per_word;
        wait_queue_head_t wait;
-       u8 errors;
+       u32 errors;
        u32 status;
 };
 
@@ -157,18 +157,18 @@ static int rzv2m_csi_start_stop_operation(const struct rzv2m_csi_priv *csi,
 
 static int rzv2m_csi_fill_txfifo(struct rzv2m_csi_priv *csi)
 {
-       int i;
+       unsigned int i;
 
        if (readl(csi->base + CSI_OFIFOL))
                return -EIO;
 
        if (csi->bytes_per_word == 2) {
-               u16 *buf = (u16 *)csi->txbuf;
+               const u16 *buf = csi->txbuf;
 
                for (i = 0; i < csi->words_to_transfer; i++)
                        writel(buf[i], csi->base + CSI_OFIFO);
        } else {
-               u8 *buf = (u8 *)csi->txbuf;
+               const u8 *buf = csi->txbuf;
 
                for (i = 0; i < csi->words_to_transfer; i++)
                        writel(buf[i], csi->base + CSI_OFIFO);
@@ -182,18 +182,18 @@ static int rzv2m_csi_fill_txfifo(struct rzv2m_csi_priv *csi)
 
 static int rzv2m_csi_read_rxfifo(struct rzv2m_csi_priv *csi)
 {
-       int i;
+       unsigned int i;
 
        if (readl(csi->base + CSI_IFIFOL) != csi->bytes_to_transfer)
                return -EIO;
 
        if (csi->bytes_per_word == 2) {
-               u16 *buf = (u16 *)csi->rxbuf;
+               u16 *buf = csi->rxbuf;
 
                for (i = 0; i < csi->words_to_transfer; i++)
                        buf[i] = (u16)readl(csi->base + CSI_IFIFO);
        } else {
-               u8 *buf = (u8 *)csi->rxbuf;
+               u8 *buf = csi->rxbuf;
 
                for (i = 0; i < csi->words_to_transfer; i++)
                        buf[i] = (u8)readl(csi->base + CSI_IFIFO);
@@ -207,9 +207,9 @@ static int rzv2m_csi_read_rxfifo(struct rzv2m_csi_priv *csi)
 
 static inline void rzv2m_csi_calc_current_transfer(struct rzv2m_csi_priv *csi)
 {
-       int bytes_transferred = max_t(int, csi->bytes_received, csi->bytes_sent);
-       int bytes_remaining = csi->buffer_len - bytes_transferred;
-       int to_transfer;
+       unsigned int bytes_transferred = max(csi->bytes_received, csi->bytes_sent);
+       unsigned int bytes_remaining = csi->buffer_len - bytes_transferred;
+       unsigned int to_transfer;
 
        if (csi->txbuf)
                /*
@@ -217,9 +217,9 @@ static inline void rzv2m_csi_calc_current_transfer(struct rzv2m_csi_priv *csi)
                 * hard to raise an overflow error (which is only possible
                 * when IP transmits and receives at the same time).
                 */
-               to_transfer = min_t(int, CSI_FIFO_HALF_SIZE, bytes_remaining);
+               to_transfer = min(CSI_FIFO_HALF_SIZE, bytes_remaining);
        else
-               to_transfer = min_t(int, CSI_FIFO_SIZE_BYTES, bytes_remaining);
+               to_transfer = min(CSI_FIFO_SIZE_BYTES, bytes_remaining);
 
        if (csi->bytes_per_word == 2)
                to_transfer >>= 1;
@@ -339,7 +339,7 @@ static inline int rzv2m_csi_wait_for_rx_ready(struct rzv2m_csi_priv *csi)
 
 static irqreturn_t rzv2m_csi_irq_handler(int irq, void *data)
 {
-       struct rzv2m_csi_priv *csi = (struct rzv2m_csi_priv *)data;
+       struct rzv2m_csi_priv *csi = data;
 
        csi->status = readl(csi->base + CSI_INT);
        rzv2m_csi_disable_irqs(csi, csi->status);