[PATCH 06/13] i2c: nomadik: use bitops helpers

Théo Lebrun
2024-02-15T16:52:39Z

Constant register bit fields are declared using hardcoded hex values;
replace them by calls to BIT() and GENMASK(). Replace custom GEN_MASK()
macro by the generic FIELD_PREP(). Replace manual bit manipulations by
the generic FIELD_GET() macro.

Signed-off-by: Théo Lebrun <theo.lebrun@bootlin.com>
---
drivers/i2c/busses/i2c-nomadik.c | 150 ++++++++++++++++++++-------------------
1 file changed, 77 insertions(+), 73 deletions(-)

diff --git a/drivers/i2c/busses/i2c-nomadik.c b/drivers/i2c/busses/i2c-nomadik.c
index 80bdf7e42613..aa68ab402b10 100644
--- a/drivers/i2c/busses/i2c-nomadik.c
+++ b/drivers/i2c/busses/i2c-nomadik.c
@@ -9,6 +9,7 @@
* Author: Srinidhi Kasagar <srinidhi.kasagar@stericsson.com>
* Author: Sachin Verma <sachin.verma@st.com>
*/
+#include <linux/bitfield.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/amba/bus.h>
@@ -42,54 +43,59 @@
#define I2C_ICR (0x038)

/* Control registers */
-#define I2C_CR_PE (0x1 << 0) /* Peripheral Enable */
-#define I2C_CR_OM (0x3 << 1) /* Operating mode */
-#define I2C_CR_SAM (0x1 << 3) /* Slave addressing mode */
-#define I2C_CR_SM (0x3 << 4) /* Speed mode */
-#define I2C_CR_SGCM (0x1 << 6) /* Slave general call mode */
-#define I2C_CR_FTX (0x1 << 7) /* Flush Transmit */
-#define I2C_CR_FRX (0x1 << 8) /* Flush Receive */
-#define I2C_CR_DMA_TX_EN (0x1 << 9) /* DMA Tx enable */
-#define I2C_CR_DMA_RX_EN (0x1 << 10) /* DMA Rx Enable */
-#define I2C_CR_DMA_SLE (0x1 << 11) /* DMA sync. logic enable */
-#define I2C_CR_LM (0x1 << 12) /* Loopback mode */
-#define I2C_CR_FON (0x3 << 13) /* Filtering on */
-#define I2C_CR_FS (0x3 << 15) /* Force stop enable */
+#define I2C_CR_PE BIT(0) /* Peripheral Enable */
+#define I2C_CR_OM GENMASK(2, 1) /* Operating mode */
+#define I2C_CR_SAM BIT(3) /* Slave addressing mode */
+#define I2C_CR_SM GENMASK(5, 4) /* Speed mode */
+#define I2C_CR_SGCM BIT(6) /* Slave general call mode */
+#define I2C_CR_FTX BIT(7) /* Flush Transmit */
+#define I2C_CR_FRX BIT(8) /* Flush Receive */
+#define I2C_CR_DMA_TX_EN BIT(9) /* DMA Tx enable */
+#define I2C_CR_DMA_RX_EN BIT(10) /* DMA Rx Enable */
+#define I2C_CR_DMA_SLE BIT(11) /* DMA sync. logic enable */
+#define I2C_CR_LM BIT(12) /* Loopback mode */
+#define I2C_CR_FON GENMASK(14, 13) /* Filtering on */
+#define I2C_CR_FS GENMASK(16, 15) /* Force stop enable */
+
+/* Slave control register (SCR) */
+#define I2C_SCR_SLSU GENMASK(31, 16) /* Slave data setup time */

/* Master controller (MCR) register */
-#define I2C_MCR_OP (0x1 << 0) /* Operation */
-#define I2C_MCR_A7 (0x7f << 1) /* 7-bit address */
-#define I2C_MCR_EA10 (0x7 << 8) /* 10-bit Extended address */
-#define I2C_MCR_SB (0x1 << 11) /* Extended address */
-#define I2C_MCR_AM (0x3 << 12) /* Address type */
-#define I2C_MCR_STOP (0x1 << 14) /* Stop condition */
-#define I2C_MCR_LENGTH (0x7ff << 15) /* Transaction length */
+#define I2C_MCR_OP BIT(0) /* Operation */
+#define I2C_MCR_A7 GENMASK(7, 1) /* 7-bit address */
+#define I2C_MCR_EA10 GENMASK(10, 8) /* 10-bit Extended address */
+#define I2C_MCR_SB BIT(11) /* Extended address */
+#define I2C_MCR_AM GENMASK(13, 12) /* Address type */
+#define I2C_MCR_STOP BIT(14) /* Stop condition */
+#define I2C_MCR_LENGTH GENMASK(25, 15) /* Transaction length */

/* Status register (SR) */
-#define I2C_SR_OP (0x3 << 0) /* Operation */
-#define I2C_SR_STATUS (0x3 << 2) /* controller status */
-#define I2C_SR_CAUSE (0x7 << 4) /* Abort cause */
-#define I2C_SR_TYPE (0x3 << 7) /* Receive type */
-#define I2C_SR_LENGTH (0x7ff << 9) /* Transfer length */
+#define I2C_SR_OP GENMASK(1, 0) /* Operation */
+#define I2C_SR_STATUS GENMASK(3, 2) /* controller status */
+#define I2C_SR_CAUSE GENMASK(6, 4) /* Abort cause */
+#define I2C_SR_TYPE GENMASK(8, 7) /* Receive type */
+#define I2C_SR_LENGTH GENMASK(19, 9) /* Transfer length */
+
+/* Baud-rate counter register (BRCR) */
+#define I2C_BRCR_BRCNT1 GENMASK(31, 16) /* Baud-rate counter 1 */
+#define I2C_BRCR_BRCNT2 GENMASK(15, 0) /* Baud-rate counter 2 */

/* Interrupt mask set/clear (IMSCR) bits */
-#define I2C_IT_TXFE (0x1 << 0)
-#define I2C_IT_TXFNE (0x1 << 1)
-#define I2C_IT_TXFF (0x1 << 2)
-#define I2C_IT_TXFOVR (0x1 << 3)
-#define I2C_IT_RXFE (0x1 << 4)
-#define I2C_IT_RXFNF (0x1 << 5)
-#define I2C_IT_RXFF (0x1 << 6)
-#define I2C_IT_RFSR (0x1 << 16)
-#define I2C_IT_RFSE (0x1 << 17)
-#define I2C_IT_WTSR (0x1 << 18)
-#define I2C_IT_MTD (0x1 << 19)
-#define I2C_IT_STD (0x1 << 20)
-#define I2C_IT_MAL (0x1 << 24)
-#define I2C_IT_BERR (0x1 << 25)
-#define I2C_IT_MTDWS (0x1 << 28)
-
-#define GEN_MASK(val, mask, sb) (((val) << (sb)) & (mask))
+#define I2C_IT_TXFE BIT(0)
+#define I2C_IT_TXFNE BIT(1)
+#define I2C_IT_TXFF BIT(2)
+#define I2C_IT_TXFOVR BIT(3)
+#define I2C_IT_RXFE BIT(4)
+#define I2C_IT_RXFNF BIT(5)
+#define I2C_IT_RXFF BIT(6)
+#define I2C_IT_RFSR BIT(16)
+#define I2C_IT_RFSE BIT(17)
+#define I2C_IT_WTSR BIT(18)
+#define I2C_IT_MTD BIT(19)
+#define I2C_IT_STD BIT(20)
+#define I2C_IT_MAL BIT(24)
+#define I2C_IT_BERR BIT(25)
+#define I2C_IT_MTDWS BIT(28)

/* some bits in ICR are reserved */
#define I2C_CLEAR_ALL_INTS 0x131f007f
@@ -284,7 +290,7 @@ static int init_hw(struct nmk_i2c_dev *priv)
}

/* enable peripheral, master mode operation */
-#define DEFAULT_I2C_REG_CR ((1 << 1) | I2C_CR_PE)
+#define DEFAULT_I2C_REG_CR (FIELD_PREP(I2C_CR_OM, 0b01) | I2C_CR_PE)

/**
* load_i2c_mcr_reg() - load the MCR register
@@ -296,41 +302,42 @@ static u32 load_i2c_mcr_reg(struct nmk_i2c_dev *priv, u16 flags)
u32 mcr = 0;
unsigned short slave_adr_3msb_bits;

- mcr |= GEN_MASK(priv->cli.slave_adr, I2C_MCR_A7, 1);
+ mcr |= FIELD_PREP(I2C_MCR_A7, priv->cli.slave_adr);

if (unlikely(flags & I2C_M_TEN)) {
/* 10-bit address transaction */
- mcr |= GEN_MASK(2, I2C_MCR_AM, 12);
+ mcr |= FIELD_PREP(I2C_MCR_AM, 2);
/*
* Get the top 3 bits.
* EA10 represents extended address in MCR. This includes
* the extension (MSB bits) of the 7 bit address loaded
* in A7
*/
- slave_adr_3msb_bits = (priv->cli.slave_adr >> 7) & 0x7;
+ slave_adr_3msb_bits = FIELD_GET(GENMASK(9, 7),
+ priv->cli.slave_adr);

- mcr |= GEN_MASK(slave_adr_3msb_bits, I2C_MCR_EA10, 8);
+ mcr |= FIELD_PREP(I2C_MCR_EA10, slave_adr_3msb_bits);
} else {
/* 7-bit address transaction */
- mcr |= GEN_MASK(1, I2C_MCR_AM, 12);
+ mcr |= FIELD_PREP(I2C_MCR_AM, 1);
}

/* start byte procedure not applied */
- mcr |= GEN_MASK(0, I2C_MCR_SB, 11);
+ mcr |= FIELD_PREP(I2C_MCR_SB, 0);

/* check the operation, master read/write? */
if (priv->cli.operation == I2C_WRITE)
- mcr |= GEN_MASK(I2C_WRITE, I2C_MCR_OP, 0);
+ mcr |= FIELD_PREP(I2C_MCR_OP, I2C_WRITE);
else
- mcr |= GEN_MASK(I2C_READ, I2C_MCR_OP, 0);
+ mcr |= FIELD_PREP(I2C_MCR_OP, I2C_READ);

/* stop or repeated start? */
if (priv->stop)
- mcr |= GEN_MASK(1, I2C_MCR_STOP, 14);
+ mcr |= FIELD_PREP(I2C_MCR_STOP, 1);
else
- mcr &= ~(GEN_MASK(1, I2C_MCR_STOP, 14));
+ mcr &= ~FIELD_PREP(I2C_MCR_STOP, 1);

- mcr |= GEN_MASK(priv->cli.count, I2C_MCR_LENGTH, 15);
+ mcr |= FIELD_PREP(I2C_MCR_LENGTH, priv->cli.count);

return mcr;
}
@@ -383,7 +390,7 @@ static void setup_i2c_controller(struct nmk_i2c_dev *priv)
slsu += 1;

dev_dbg(&priv->adev->dev, "calculated SLSU = %04x\n", slsu);
- writel(slsu << 16, priv->virtbase + I2C_SCR);
+ writel(FIELD_PREP(I2C_SCR_SLSU, slsu), priv->virtbase + I2C_SCR);

/*
* The spec says, in case of std. mode the divider is
@@ -399,8 +406,8 @@ static void setup_i2c_controller(struct nmk_i2c_dev *priv)
* plus operation. Currently we do not supprt high speed mode
* so set brcr1 to 0.
*/
- brcr1 = 0 << 16;
- brcr2 = (i2c_clk / (priv->clk_freq * div)) & 0xffff;
+ brcr1 = FIELD_PREP(I2C_BRCR_BRCNT1, 0);
+ brcr2 = FIELD_PREP(I2C_BRCR_BRCNT2, i2c_clk / (priv->clk_freq * div));

/* set the baud rate counter register */
writel((brcr1 | brcr2), priv->virtbase + I2C_BRCR);
@@ -414,12 +421,13 @@ static void setup_i2c_controller(struct nmk_i2c_dev *priv)
if (priv->sm > I2C_FREQ_MODE_FAST) {
dev_err(&priv->adev->dev,
"do not support this mode defaulting to std. mode\n");
- brcr2 = i2c_clk / (I2C_MAX_STANDARD_MODE_FREQ * 2) & 0xffff;
+ brcr2 = FIELD_PREP(I2C_BRCR_BRCNT2,
+ i2c_clk / (I2C_MAX_STANDARD_MODE_FREQ * 2));
writel((brcr1 | brcr2), priv->virtbase + I2C_BRCR);
- writel(I2C_FREQ_MODE_STANDARD << 4,
- priv->virtbase + I2C_CR);
+ writel(FIELD_PREP(I2C_CR_SM, I2C_FREQ_MODE_STANDARD),
+ priv->virtbase + I2C_CR);
}
- writel(priv->sm << 4, priv->virtbase + I2C_CR);
+ writel(FIELD_PREP(I2C_CR_SM, priv->sm), priv->virtbase + I2C_CR);

/* set the Tx and Rx FIFO threshold */
writel(priv->tft, priv->virtbase + I2C_TFTR);
@@ -583,13 +591,8 @@ static int nmk_i2c_xfer_one(struct nmk_i2c_dev *priv, u16 flags)
u32 cause;

i2c_sr = readl(priv->virtbase + I2C_SR);
- /*
- * Check if the controller I2C operation status
- * is set to ABORT(11b).
- */
- if (((i2c_sr >> 2) & 0x3) == 0x3) {
- /* get the abort cause */
- cause = (i2c_sr >> 4) & 0x7;
+ if (FIELD_GET(I2C_SR_STATUS, i2c_sr) == I2C_ABORT) {
+ cause = FIELD_GET(I2C_SR_CAUSE, i2c_sr);
dev_err(&priv->adev->dev, "%s\n",
cause >= ARRAY_SIZE(abort_causes) ?
"unknown reason" :
@@ -730,7 +733,7 @@ static irqreturn_t i2c_irq_handler(int irq, void *arg)
misr = readl(priv->virtbase + I2C_MISR);

src = __ffs(misr);
- switch ((1 << src)) {
+ switch (BIT(src)) {

/* Transmit FIFO nearly empty interrupt */
case I2C_IT_TXFNE:
@@ -824,15 +827,16 @@ static irqreturn_t i2c_irq_handler(int irq, void *arg)
* during the transaction.
*/
case I2C_IT_BERR:
+ {
+ u32 sr = readl(priv->virtbase + I2C_SR);
priv->result = -EIO;
- /* get the status */
- if (((readl(priv->virtbase + I2C_SR) >> 2) & 0x3) == I2C_ABORT)
+ if (FIELD_GET(I2C_SR_STATUS, sr) == I2C_ABORT)
init_hw(priv);

i2c_set_bit(priv->virtbase + I2C_ICR, I2C_IT_BERR);
complete(&priv->xfer_complete);
-
- break;
+ }
+ break;

/*
* Tx FIFO overrun interrupt.

--
2.43.1