spi/pl022: fix dubious allocation staticize platform data

This removes some dubious allocation of a local chipinfo struct
in favor of a constant preset, tagging that one const revealed
further problems with platform data being modified so fixed up
these too.
Reported-by: NVirupax Sadashivpetimath <virupax.sadashivpetimath@stericsson.com>
Signed-off-by: NLinus Walleij <linus.walleij@stericsson.com>
Signed-off-by: NGrant Likely <grant.likely@secretlab.ca>

drivers/spi/amba-pl022.c

@@ -1593,7 +1593,7 @@ static int destroy_queue(struct pl022 *pl022)
 }
 
 static int verify_controller_parameters(struct pl022 *pl022,
-					struct pl022_config_chip *chip_info)
+				struct pl022_config_chip const *chip_info)
 {
 	if ((chip_info->iface < SSP_INTERFACE_MOTOROLA_SPI)
 	    || (chip_info->iface > SSP_INTERFACE_UNIDIRECTIONAL)) {
@@ -1614,12 +1614,6 @@ static int verify_controller_parameters(struct pl022 *pl022,
 			"hierarchy is configured incorrectly\n");
 		return -EINVAL;
 	}
-	if (((chip_info->clk_freq).cpsdvsr < CPSDVR_MIN)
-	    || ((chip_info->clk_freq).cpsdvsr > CPSDVR_MAX)) {
-		dev_err(&pl022->adev->dev,
-			"cpsdvsr is configured incorrectly\n");
-		return -EINVAL;
-	}
 	if ((chip_info->com_mode != INTERRUPT_TRANSFER)
 	    && (chip_info->com_mode != DMA_TRANSFER)
 	    && (chip_info->com_mode != POLLING_TRANSFER)) {
@@ -1671,11 +1665,6 @@ static int verify_controller_parameters(struct pl022 *pl022,
 			return -EINVAL;
 		}
 	}
-	if (chip_info->cs_control == NULL) {
-		dev_warn(&pl022->adev->dev,
-			"Chip Select Function is NULL for this chip\n");
-		chip_info->cs_control = null_cs_control;
-	}
 	return 0;
 }
 
@@ -1775,6 +1764,25 @@ static int calculate_effective_freq(struct pl022 *pl022,
 	return 0;
 }
 
+
+/*
+ * A piece of default chip info unless the platform
+ * supplies it.
+ */
+static const struct pl022_config_chip pl022_default_chip_info = {
+	.com_mode = POLLING_TRANSFER,
+	.iface = SSP_INTERFACE_MOTOROLA_SPI,
+	.hierarchy = SSP_SLAVE,
+	.slave_tx_disable = DO_NOT_DRIVE_TX,
+	.rx_lev_trig = SSP_RX_1_OR_MORE_ELEM,
+	.tx_lev_trig = SSP_TX_1_OR_MORE_EMPTY_LOC,
+	.ctrl_len = SSP_BITS_8,
+	.wait_state = SSP_MWIRE_WAIT_ZERO,
+	.duplex = SSP_MICROWIRE_CHANNEL_FULL_DUPLEX,
+	.cs_control = null_cs_control,
+};
+
+
 /**
  * pl022_setup - setup function registered to SPI master framework
  * @spi: spi device which is requesting setup
@@ -1789,8 +1797,9 @@ static int calculate_effective_freq(struct pl022 *pl022,
  */
 static int pl022_setup(struct spi_device *spi)
 {
-	struct pl022_config_chip *chip_info;
+	struct pl022_config_chip const *chip_info;
 	struct chip_data *chip;
+	struct ssp_clock_params clk_freq;
 	int status = 0;
 	struct pl022 *pl022 = spi_master_get_devdata(spi->master);
 	unsigned int bits = spi->bits_per_word;
@@ -1817,40 +1826,13 @@ static int pl022_setup(struct spi_device *spi)
 	chip_info = spi->controller_data;
 
 	if (chip_info == NULL) {
+		chip_info = &pl022_default_chip_info;
 		/* spi_board_info.controller_data not is supplied */
 		dev_dbg(&spi->dev,
 			"using default controller_data settings\n");
-
-		chip_info =
-			kzalloc(sizeof(struct pl022_config_chip), GFP_KERNEL);
-
-		if (!chip_info) {
-			dev_err(&spi->dev,
-				"cannot allocate controller data\n");
-			status = -ENOMEM;
-			goto err_first_setup;
-		}
-
-		dev_dbg(&spi->dev, "allocated memory for controller data\n");
-
-		/*
-		 * Set controller data default values:
-		 * Polling is supported by default
-		 */
-		chip_info->com_mode = POLLING_TRANSFER;
-		chip_info->iface = SSP_INTERFACE_MOTOROLA_SPI;
-		chip_info->hierarchy = SSP_SLAVE;
-		chip_info->slave_tx_disable = DO_NOT_DRIVE_TX;
-		chip_info->rx_lev_trig = SSP_RX_1_OR_MORE_ELEM;
-		chip_info->tx_lev_trig = SSP_TX_1_OR_MORE_EMPTY_LOC;
-		chip_info->ctrl_len = SSP_BITS_8;
-		chip_info->wait_state = SSP_MWIRE_WAIT_ZERO;
-		chip_info->duplex = SSP_MICROWIRE_CHANNEL_FULL_DUPLEX;
-		chip_info->cs_control = null_cs_control;
-	} else {
+	} else
 		dev_dbg(&spi->dev,
 			"using user supplied controller_data settings\n");
-	}
 
 	/*
 	 * We can override with custom divisors, else we use the board
@@ -1860,21 +1842,36 @@ static int pl022_setup(struct spi_device *spi)
 	    && (0 == chip_info->clk_freq.scr)) {
 		status = calculate_effective_freq(pl022,
 						  spi->max_speed_hz,
-						  &chip_info->clk_freq);
+						  &clk_freq);
 		if (status < 0)
 			goto err_config_params;
 	} else {
-		if ((chip_info->clk_freq.cpsdvsr % 2) != 0)
-			chip_info->clk_freq.cpsdvsr =
-				chip_info->clk_freq.cpsdvsr - 1;
+		memcpy(&clk_freq, &chip_info->clk_freq, sizeof(clk_freq));
+		if ((clk_freq.cpsdvsr % 2) != 0)
+			clk_freq.cpsdvsr =
+				clk_freq.cpsdvsr - 1;
+	}
+	if ((clk_freq.cpsdvsr < CPSDVR_MIN)
+	    || (clk_freq.cpsdvsr > CPSDVR_MAX)) {
+		dev_err(&spi->dev,
+			"cpsdvsr is configured incorrectly\n");
+		goto err_config_params;
 	}
+
+
 	status = verify_controller_parameters(pl022, chip_info);
 	if (status) {
 		dev_err(&spi->dev, "controller data is incorrect");
 		goto err_config_params;
 	}
+
 	/* Now set controller state based on controller data */
 	chip->xfer_type = chip_info->com_mode;
+	if (!chip_info->cs_control) {
+		chip->cs_control = null_cs_control;
+		dev_warn(&spi->dev,
+			 "chip select function is NULL for this chip\n");
+	} else
 		chip->cs_control = chip_info->cs_control;
 
 	if (bits <= 3) {
@@ -1932,7 +1929,7 @@ static int pl022_setup(struct spi_device *spi)
 			       SSP_DMACR_MASK_TXDMAE, 1);
 	}
 
-	chip->cpsr = chip_info->clk_freq.cpsdvsr;
+	chip->cpsr = clk_freq.cpsdvsr;
 
 	/* Special setup for the ST micro extended control registers */
 	if (pl022->vendor->extended_cr) {
@@ -1989,7 +1986,7 @@ static int pl022_setup(struct spi_device *spi)
 		tmp = SSP_CLK_FIRST_EDGE;
 	SSP_WRITE_BITS(chip->cr0, tmp, SSP_CR0_MASK_SPH, 7);
 
-	SSP_WRITE_BITS(chip->cr0, chip_info->clk_freq.scr, SSP_CR0_MASK_SCR, 8);
+	SSP_WRITE_BITS(chip->cr0, clk_freq.scr, SSP_CR0_MASK_SCR, 8);
 	/* Loopback is available on all versions except PL023 */
 	if (!pl022->vendor->pl023) {
 		if (spi->mode & SPI_LOOP)
@@ -2007,7 +2004,6 @@ static int pl022_setup(struct spi_device *spi)
 	return status;
  err_config_params:
 	spi_set_ctldata(spi, NULL);
- err_first_setup:
 	kfree(chip);
 	return status;
 }