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From:   Zev Weiss <zev@bewilderbeest.net>
To:     openbmc@lists.ozlabs.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Jeremy Kerr <jk@codeconstruct.com.au>,
        Joel Stanley <joel@jms.id.au>,
        =?UTF-8?q?C=C3=A9dric=20Le=20Goater?= <clg@kaod.org>,
        Zev Weiss <zev@bewilderbeest.net>,
        Tudor Ambarus <tudor.ambarus@microchip.com>,
        Michael Walle <michael@walle.cc>,
        Pratyush Yadav <p.yadav@ti.com>,
        Miquel Raynal <miquel.raynal@bootlin.com>,
        Richard Weinberger <richard@nod.at>,
        Vignesh Raghavendra <vigneshr@ti.com>,
        Andrew Jeffery <andrew@aj.id.au>,
        linux-mtd@lists.infradead.org,
        linux-arm-kernel@lists.infradead.org,
        linux-aspeed@lists.ozlabs.org, linux-kernel@vger.kernel.org
Subject: [PATCH 3/6] mtd: spi-nor: aspeed: Refactor registration/unregistration
Date:   Wed, 29 Sep 2021 04:54:05 -0700
Message-Id: <20210929115409.21254-4-zev@bewilderbeest.net>
In-Reply-To: <20210929115409.21254-1-zev@bewilderbeest.net>
References: <20210929115409.21254-1-zev@bewilderbeest.net>
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We now have separate functions for registering and unregistering
individual flash chips, instead of the entire controller.  This is a
preparatory step for allowing userspace to request that a specific
chip be attached or detached at runtime.

Signed-off-by: Zev Weiss <zev@bewilderbeest.net>
---
 drivers/mtd/spi-nor/controllers/aspeed-smc.c | 73 ++++++++++++--------
 1 file changed, 45 insertions(+), 28 deletions(-)

diff --git a/drivers/mtd/spi-nor/controllers/aspeed-smc.c b/drivers/mtd/spi-nor/controllers/aspeed-smc.c
index 7225870e8b18..3c153104a905 100644
--- a/drivers/mtd/spi-nor/controllers/aspeed-smc.c
+++ b/drivers/mtd/spi-nor/controllers/aspeed-smc.c
@@ -107,9 +107,10 @@ struct aspeed_smc_controller {
 	const struct aspeed_smc_info *info;	/* type info of controller */
 	void __iomem *regs;			/* controller registers */
 	void __iomem *ahb_base;			/* per-chip windows resource */
+	struct resource *ahb_res;		/* resource for AHB address space */
 	u32 ahb_window_size;			/* full mapping window size */
 
-	struct aspeed_smc_chip *chips[];	/* pointers to attached chips */
+	struct aspeed_smc_chip *chips[];	/* pointers to connected chips */
 };
 
 /*
@@ -399,15 +400,24 @@ static ssize_t aspeed_smc_write_user(struct spi_nor *nor, loff_t to,
 	return len;
 }
 
+static int aspeed_smc_unregister_chip(struct aspeed_smc_chip *chip)
+{
+	return mtd_device_unregister(&chip->nor.mtd);
+}
+
 static int aspeed_smc_unregister(struct aspeed_smc_controller *controller)
 {
 	struct aspeed_smc_chip *chip;
-	int n;
+	int n, ret;
 
 	for (n = 0; n < controller->info->nce; n++) {
 		chip = controller->chips[n];
-		if (chip)
-			mtd_device_unregister(&chip->nor.mtd);
+		if (chip) {
+			ret = aspeed_smc_unregister_chip(chip);
+			if (ret)
+				dev_warn(controller->dev, "failed to unregister CS%d: %d\n",
+				         n, ret);
+		}
 	}
 
 	return 0;
@@ -756,14 +766,39 @@ static const struct spi_nor_controller_ops aspeed_smc_controller_ops = {
 	.write = aspeed_smc_write_user,
 };
 
-static int aspeed_smc_setup_flash(struct aspeed_smc_controller *controller,
-				  struct device_node *np, struct resource *r)
+static int aspeed_smc_register_chip(struct aspeed_smc_chip *chip)
 {
-	const struct spi_nor_hwcaps hwcaps = {
+	static const struct spi_nor_hwcaps hwcaps = {
 		.mask = SNOR_HWCAPS_READ |
 			SNOR_HWCAPS_READ_FAST |
 			SNOR_HWCAPS_PP,
 	};
+	int ret;
+
+	ret = aspeed_smc_chip_setup_init(chip, chip->controller->ahb_res);
+	if (ret)
+		goto out;
+
+	/*
+	 * TODO: Add support for Dual and Quad SPI protocols attach when board
+	 * support is present as determined by of property.
+	 */
+	ret = spi_nor_scan(&chip->nor, NULL, &hwcaps);
+	if (ret)
+		goto out;
+
+	ret = aspeed_smc_chip_setup_finish(chip);
+	if (ret)
+		goto out;
+
+	ret = mtd_device_register(&chip->nor.mtd, NULL, 0);
+out:
+	return ret;
+}
+
+static int aspeed_smc_setup_flash(struct aspeed_smc_controller *controller,
+				  struct device_node *np, struct resource *r)
+{
 	const struct aspeed_smc_info *info = controller->info;
 	struct device *dev = controller->dev;
 	struct device_node *child;
@@ -773,7 +808,6 @@ static int aspeed_smc_setup_flash(struct aspeed_smc_controller *controller,
 	for_each_available_child_of_node(np, child) {
 		struct aspeed_smc_chip *chip;
 		struct spi_nor *nor;
-		struct mtd_info *mtd;
 
 		/* This driver does not support NAND or NOR flash devices. */
 		if (!of_device_is_compatible(child, "jedec,spi-nor"))
@@ -810,35 +844,17 @@ static int aspeed_smc_setup_flash(struct aspeed_smc_controller *controller,
 		chip->cs = cs;
 
 		nor = &chip->nor;
-		mtd = &nor->mtd;
 
 		nor->dev = dev;
 		nor->priv = chip;
 		spi_nor_set_flash_node(nor, child);
 		nor->controller_ops = &aspeed_smc_controller_ops;
 
-		ret = aspeed_smc_chip_setup_init(chip, r);
-		if (ret)
-			break;
-
-		/*
-		 * TODO: Add support for Dual and Quad SPI protocols
-		 * attach when board support is present as determined
-		 * by of property.
-		 */
-		ret = spi_nor_scan(nor, NULL, &hwcaps);
-		if (ret)
-			break;
-
-		ret = aspeed_smc_chip_setup_finish(chip);
-		if (ret)
-			break;
+		controller->chips[cs] = chip;
 
-		ret = mtd_device_register(mtd, NULL, 0);
+		ret = aspeed_smc_register_chip(chip);
 		if (ret)
 			break;
-
-		controller->chips[cs] = chip;
 	}
 
 	if (ret) {
@@ -881,6 +897,7 @@ static int aspeed_smc_probe(struct platform_device *pdev)
 		return PTR_ERR(controller->regs);
 
 	res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
+	controller->ahb_res = res;
 	controller->ahb_base = devm_ioremap_resource(dev, res);
 	if (IS_ERR(controller->ahb_base))
 		return PTR_ERR(controller->ahb_base);
-- 
2.33.0