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2024-02-20 102a0743326a03cd1a1202ceda21e175b7d3575c

 kernel/drivers/spi/spi-altera.c
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@@ -1,3 +1,4 @@
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+// SPDX-License-Identifier: GPL-2.0-only
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 /*
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  * Altera SPI driver
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  *
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@@ -7,16 +8,13 @@
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  * Copyright (c) 2006 Ben Dooks
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  * Copyright (c) 2006 Simtec Electronics
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  *	Ben Dooks <ben@simtec.co.uk>
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- *
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- * This program is free software; you can redistribute it and/or modify
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- * it under the terms of the GNU General Public License version 2 as
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- * published by the Free Software Foundation.
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  */
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12
 
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 #include <linux/interrupt.h>
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 #include <linux/errno.h>
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 #include <linux/module.h>
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 #include <linux/platform_device.h>
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+#include <linux/spi/altera.h>
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 #include <linux/spi/spi.h>
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 #include <linux/io.h>
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 #include <linux/of.h>
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@@ -43,18 +41,60 @@
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 #define ALTERA_SPI_CONTROL_IE_MSK	0x100
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 #define ALTERA_SPI_CONTROL_SSO_MSK	0x400
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43
 
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+#define ALTERA_SPI_MAX_CS		32
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+
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+enum altera_spi_type {
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+	ALTERA_SPI_TYPE_UNKNOWN,
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+	ALTERA_SPI_TYPE_SUBDEV,
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+};
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+
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 struct altera_spi {
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-	void __iomem *base;
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 	int irq;
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 	int len;
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 	int count;
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 	int bytes_per_word;
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-	unsigned long imr;
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+	u32 imr;
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57
 
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 	/* data buffers */
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 	const unsigned char *tx;
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 	unsigned char *rx;
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+
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+	struct regmap *regmap;
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+	u32 regoff;
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+	struct device *dev;
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 };
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+
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+static const struct regmap_config spi_altera_config = {
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+	.reg_bits = 32,
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+	.reg_stride = 4,
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+	.val_bits = 32,
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+	.fast_io = true,
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+};
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+
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+static int altr_spi_writel(struct altera_spi *hw, unsigned int reg,
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+			   unsigned int val)
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+{
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+	int ret;
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+
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+	ret = regmap_write(hw->regmap, hw->regoff + reg, val);
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+	if (ret)
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+		dev_err(hw->dev, "fail to write reg 0x%x val 0x%x: %d\n",
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+			reg, val, ret);
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+
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+	return ret;
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+}
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+
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+static int altr_spi_readl(struct altera_spi *hw, unsigned int reg,
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+			  unsigned int *val)
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+{
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+	int ret;
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+
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+	ret = regmap_read(hw->regmap, hw->regoff + reg, val);
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+	if (ret)
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+		dev_err(hw->dev, "fail to read reg 0x%x: %d\n", reg, ret);
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+
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+	return ret;
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+}
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98
 
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 static inline struct altera_spi *altera_spi_to_hw(struct spi_device *sdev)
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 {
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@@ -67,12 +107,13 @@
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107
 
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 	if (is_high) {
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 		hw->imr &= ~ALTERA_SPI_CONTROL_SSO_MSK;
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-		writel(hw->imr, hw->base + ALTERA_SPI_CONTROL);
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-		writel(0, hw->base + ALTERA_SPI_SLAVE_SEL);
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+		altr_spi_writel(hw, ALTERA_SPI_CONTROL, hw->imr);
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+		altr_spi_writel(hw, ALTERA_SPI_SLAVE_SEL, 0);
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 	} else {
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-		writel(BIT(spi->chip_select), hw->base + ALTERA_SPI_SLAVE_SEL);
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+		altr_spi_writel(hw, ALTERA_SPI_SLAVE_SEL,
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+				BIT(spi->chip_select));
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 		hw->imr |= ALTERA_SPI_CONTROL_SSO_MSK;
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-		writel(hw->imr, hw->base + ALTERA_SPI_CONTROL);
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+		altr_spi_writel(hw, ALTERA_SPI_CONTROL, hw->imr);
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 	}
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 }
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119
 
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@@ -89,17 +130,24 @@
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 			txd = (hw->tx[hw->count * 2]
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 				| (hw->tx[hw->count * 2 + 1] << 8));
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 			break;
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+		case 4:
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+			txd = (hw->tx[hw->count * 4]
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+				| (hw->tx[hw->count * 4 + 1] << 8)
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+				| (hw->tx[hw->count * 4 + 2] << 16)
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+				| (hw->tx[hw->count * 4 + 3] << 24));
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+			break;
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+
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 		}
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 	}
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142
 
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-	writel(txd, hw->base + ALTERA_SPI_TXDATA);
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+	altr_spi_writel(hw, ALTERA_SPI_TXDATA, txd);
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 }
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145
 
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 static void altera_spi_rx_word(struct altera_spi *hw)
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 {
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 	unsigned int rxd;
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-	rxd = readl(hw->base + ALTERA_SPI_RXDATA);
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+	altr_spi_readl(hw, ALTERA_SPI_RXDATA, &rxd);
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 	if (hw->rx) {
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 		switch (hw->bytes_per_word) {
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 		case 1:
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@@ -109,6 +157,13 @@
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 			hw->rx[hw->count * 2] = rxd;
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 			hw->rx[hw->count * 2 + 1] = rxd >> 8;
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 			break;
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+		case 4:
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+			hw->rx[hw->count * 4] = rxd;
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+			hw->rx[hw->count * 4 + 1] = rxd >> 8;
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+			hw->rx[hw->count * 4 + 2] = rxd >> 16;
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+			hw->rx[hw->count * 4 + 3] = rxd >> 24;
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+			break;
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+
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 		}
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 	}
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@@ -119,6 +174,7 @@
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 	struct spi_device *spi, struct spi_transfer *t)
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 {
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 	struct altera_spi *hw = spi_master_get_devdata(master);
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+	u32 val;
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 	hw->tx = t->tx_buf;
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 	hw->rx = t->rx_buf;
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@@ -129,24 +185,30 @@
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 	if (hw->irq >= 0) {
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 		/* enable receive interrupt */
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 		hw->imr |= ALTERA_SPI_CONTROL_IRRDY_MSK;
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-		writel(hw->imr, hw->base + ALTERA_SPI_CONTROL);
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+		altr_spi_writel(hw, ALTERA_SPI_CONTROL, hw->imr);
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189
 
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 		/* send the first byte */
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 		altera_spi_tx_word(hw);
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-	} else {
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-		while (hw->count < hw->len) {
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-			altera_spi_tx_word(hw);
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-			while (!(readl(hw->base + ALTERA_SPI_STATUS) &
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-				 ALTERA_SPI_STATUS_RRDY_MSK))
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-				cpu_relax();
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-
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-			altera_spi_rx_word(hw);
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-		}
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-		spi_finalize_current_transfer(master);
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+		return 1;
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 	}
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-	return t->len;
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+	while (hw->count < hw->len) {
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+		altera_spi_tx_word(hw);
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+
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+		for (;;) {
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+			altr_spi_readl(hw, ALTERA_SPI_STATUS, &val);
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+			if (val & ALTERA_SPI_STATUS_RRDY_MSK)
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+				break;
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+
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+			cpu_relax();
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+		}
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+
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+		altera_spi_rx_word(hw);
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+	}
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+	spi_finalize_current_transfer(master);
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+
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+	return 0;
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 }
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213
 
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 static irqreturn_t altera_spi_irq(int irq, void *dev)
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@@ -161,7 +223,7 @@
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 	} else {
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 		/* disable receive interrupt */
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 		hw->imr &= ~ALTERA_SPI_CONTROL_IRRDY_MSK;
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-		writel(hw->imr, hw->base + ALTERA_SPI_CONTROL);
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+		altr_spi_writel(hw, ALTERA_SPI_CONTROL, hw->imr);
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 		spi_finalize_current_transfer(master);
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 	}
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@@ -171,10 +233,14 @@
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233
 
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 static int altera_spi_probe(struct platform_device *pdev)
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 {
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+	const struct platform_device_id *platid = platform_get_device_id(pdev);
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+	struct altera_spi_platform_data *pdata = dev_get_platdata(&pdev->dev);
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+	enum altera_spi_type type = ALTERA_SPI_TYPE_UNKNOWN;
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 	struct altera_spi *hw;
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 	struct spi_master *master;
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-	struct resource *res;
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 	int err = -ENODEV;
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+	u32 val;
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+	u16 i;
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 	master = spi_alloc_master(&pdev->dev, sizeof(struct altera_spi));
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 	if (!master)
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@@ -182,28 +248,73 @@
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 	/* setup the master state. */
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 	master->bus_num = pdev->id;
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-	master->num_chipselect = 16;
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-	master->mode_bits = SPI_CS_HIGH;
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-	master->bits_per_word_mask = SPI_BPW_RANGE_MASK(1, 16);
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+
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+	if (pdata) {
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+		if (pdata->num_chipselect > ALTERA_SPI_MAX_CS) {
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+			dev_err(&pdev->dev,
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+				"Invalid number of chipselect: %hu\n",
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+				pdata->num_chipselect);
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+			err = -EINVAL;
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+			goto exit;
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+		}
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+
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+		master->num_chipselect = pdata->num_chipselect;
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+		master->mode_bits = pdata->mode_bits;
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+		master->bits_per_word_mask = pdata->bits_per_word_mask;
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+	} else {
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+		master->num_chipselect = 16;
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+		master->mode_bits = SPI_CS_HIGH;
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+		master->bits_per_word_mask = SPI_BPW_RANGE_MASK(1, 16);
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+	}
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+
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 	master->dev.of_node = pdev->dev.of_node;
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 	master->transfer_one = altera_spi_txrx;
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 	master->set_cs = altera_spi_set_cs;
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 	hw = spi_master_get_devdata(master);
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+	hw->dev = &pdev->dev;
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+
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+	if (platid)
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+		type = platid->driver_data;
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 	/* find and map our resources */
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-	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
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-	hw->base = devm_ioremap_resource(&pdev->dev, res);
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-	if (IS_ERR(hw->base)) {
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-		err = PTR_ERR(hw->base);
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-		goto exit;
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+	if (type == ALTERA_SPI_TYPE_SUBDEV) {
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+		struct resource *regoff;
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+
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+		hw->regmap = dev_get_regmap(pdev->dev.parent, NULL);
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+		if (!hw->regmap) {
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+			dev_err(&pdev->dev, "get regmap failed\n");
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+			goto exit;
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+		}
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+
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+		regoff = platform_get_resource(pdev, IORESOURCE_REG, 0);
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+		if (regoff)
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+			hw->regoff = regoff->start;
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+	} else {
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+		void __iomem *res;
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+
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+		res = devm_platform_ioremap_resource(pdev, 0);
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+		if (IS_ERR(res)) {
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+			err = PTR_ERR(res);
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+			goto exit;
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+		}
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+
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+		hw->regmap = devm_regmap_init_mmio(&pdev->dev, res,
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+						   &spi_altera_config);
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+		if (IS_ERR(hw->regmap)) {
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+			dev_err(&pdev->dev, "regmap mmio init failed\n");
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+			err = PTR_ERR(hw->regmap);
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+			goto exit;
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+		}
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 	}
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+
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 	/* program defaults into the registers */
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 	hw->imr = 0;		/* disable spi interrupts */
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-	writel(hw->imr, hw->base + ALTERA_SPI_CONTROL);
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-	writel(0, hw->base + ALTERA_SPI_STATUS);	/* clear status reg */
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-	if (readl(hw->base + ALTERA_SPI_STATUS) & ALTERA_SPI_STATUS_RRDY_MSK)
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-		readl(hw->base + ALTERA_SPI_RXDATA);	/* flush rxdata */
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+	altr_spi_writel(hw, ALTERA_SPI_CONTROL, hw->imr);
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+	altr_spi_writel(hw, ALTERA_SPI_STATUS, 0);	/* clear status reg */
315
+	altr_spi_readl(hw, ALTERA_SPI_STATUS, &val);
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+	if (val & ALTERA_SPI_STATUS_RRDY_MSK)
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+		altr_spi_readl(hw, ALTERA_SPI_RXDATA, &val); /* flush rxdata */
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 	/* irq is optional */
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 	hw->irq = platform_get_irq(pdev, 0);
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320
 	if (hw->irq >= 0) {
..
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@@ -216,7 +327,17 @@
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 	err = devm_spi_register_master(&pdev->dev, master);
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 	if (err)
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 		goto exit;
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-	dev_info(&pdev->dev, "base %p, irq %d\n", hw->base, hw->irq);
330
+
331
+	if (pdata) {
332
+		for (i = 0; i < pdata->num_devices; i++) {
333
+			if (!spi_new_device(master, pdata->devices + i))
334
+				dev_warn(&pdev->dev,
335
+					 "unable to create SPI device: %s\n",
336
+					 pdata->devices[i].modalias);
337
+		}
338
+	}
339
+
340
+	dev_info(&pdev->dev, "regoff %u, irq %d\n", hw->regoff, hw->irq);
220
341
 
221
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 	return 0;
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343
 exit:
..
..
@@ -233,6 +354,13 @@
233
354
 MODULE_DEVICE_TABLE(of, altera_spi_match);
234
355
 #endif /* CONFIG_OF */
235
356
 
357
+static const struct platform_device_id altera_spi_ids[] = {
358
+	{ DRV_NAME,		ALTERA_SPI_TYPE_UNKNOWN },
359
+	{ "subdev_spi_altera",	ALTERA_SPI_TYPE_SUBDEV },
360
+	{ }
361
+};
362
+MODULE_DEVICE_TABLE(platform, altera_spi_ids);
363
+
236
364
 static struct platform_driver altera_spi_driver = {
237
365
 	.probe = altera_spi_probe,
238
366
 	.driver = {
..
..
@@ -240,6 +368,7 @@
240
368
 		.pm = NULL,
241
369
 		.of_match_table = of_match_ptr(altera_spi_match),
242
370
 	},
371
+	.id_table	= altera_spi_ids,
243
372
 };
244
373
 module_platform_driver(altera_spi_driver);
245
374