Commit 8582a03e authored by Masahiro Yamada's avatar Masahiro Yamada Committed by Boris Brezillon
Browse files

mtd: nand: denali: clean up comments 



This driver explains too much about what is apparent from the code.

Comments around basic APIs such as init_completion(), spin_lock_init(),
etc. seem unneeded lessons to kernel developers.
(With those comments dropped, denali_drv_init() is small enough,
so it has been merged into the probe function.)

Also, NAND driver developers should know the NAND init procedure, so
there is no need to explain nand_scan_ident/tail.

I removed FSF's address from the license blocks, and added simple
comments to struct members.

Signed-off-by: default avatarMasahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: default avatarBoris Brezillon <boris.brezillon@free-electrons.com>
parent 8e4cbf7f

drivers/mtd/nand/denali.c

+5 −47
Original line number Diff line number Diff line
@@ -10,11 +10,6 @@ 
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for

 * more details.

 *

 * You should have received a copy of the GNU General Public License along with

 * this program; if not, write to the Free Software Foundation, Inc.,

 * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.

 *

 */



#include <linux/bitfield.h>
@@ -64,10 +59,6 @@ MODULE_LICENSE("GPL"); 
 */

#define DENALI_CLK_X_MULT	6



/*

 * this macro allows us to convert from an MTD structure to our own

 * device context (denali) structure.

 */

static inline struct denali_nand_info *mtd_to_denali(struct mtd_info *mtd)

{

	return container_of(mtd_to_nand(mtd), struct denali_nand_info, nand);
@@ -450,9 +441,8 @@ static int denali_sw_ecc_fixup(struct mtd_info *mtd, 
	} while (!(err_cor_info & ERR_CORRECTION_INFO__LAST_ERR));



	/*

	 * Once handle all ecc errors, controller will trigger a

	 * ECC_TRANSACTION_DONE interrupt, so here just wait for

	 * a while for this interrupt

	 * Once handle all ECC errors, controller will trigger an

	 * ECC_TRANSACTION_DONE interrupt.

	 */

	irq_status = denali_wait_for_irq(denali, INTR__ECC_TRANSACTION_DONE);

	if (!(irq_status & INTR__ECC_TRANSACTION_DONE))
@@ -613,7 +603,6 @@ static int denali_dma_xfer(struct denali_nand_info *denali, void *buf, 
	denali_reset_irq(denali);

	denali_setup_dma(denali, dma_addr, page, write);



	/* wait for operation to complete */

	irq_status = denali_wait_for_irq(denali, irq_mask);

	if (!(irq_status & INTR__DMA_CMD_COMP))

		ret = -EIO;
@@ -1185,22 +1174,6 @@ static const struct mtd_ooblayout_ops denali_ooblayout_ops = { 
	.free = denali_ooblayout_free,

};



/* initialize driver data structures */

static void denali_drv_init(struct denali_nand_info *denali)

{

	/*

	 * the completion object will be used to notify

	 * the callee that the interrupt is done

	 */

	init_completion(&denali->complete);



	/*

	 * the spinlock will be used to synchronize the ISR with any

	 * element that might be access shared data (interrupt status)

	 */

	spin_lock_init(&denali->irq_lock);

}



static int denali_multidev_fixup(struct denali_nand_info *denali)

{

	struct nand_chip *chip = &denali->nand;
@@ -1260,11 +1233,12 @@ int denali_init(struct denali_nand_info *denali) 


	mtd->dev.parent = denali->dev;

	denali_hw_init(denali);

	denali_drv_init(denali);



	init_completion(&denali->complete);

	spin_lock_init(&denali->irq_lock);



	denali_clear_irq_all(denali);



	/* Request IRQ after all the hardware initialization is finished */

	ret = devm_request_irq(denali->dev, denali->irq, denali_isr,

			       IRQF_SHARED, DENALI_NAND_NAME, denali);

	if (ret) {
@@ -1282,7 +1256,6 @@ int denali_init(struct denali_nand_info *denali) 
	if (!mtd->name)

		mtd->name = "denali-nand";



	/* register the driver with the NAND core subsystem */

	chip->select_chip = denali_select_chip;

	chip->read_byte = denali_read_byte;

	chip->write_byte = denali_write_byte;
@@ -1295,11 +1268,6 @@ int denali_init(struct denali_nand_info *denali) 
	if (denali->clk_x_rate)

		chip->setup_data_interface = denali_setup_data_interface;



	/*

	 * scan for NAND devices attached to the controller

	 * this is the first stage in a two step process to register

	 * with the nand subsystem

	 */

	ret = nand_scan_ident(mtd, denali->max_banks, NULL);

	if (ret)

		goto disable_irq;
@@ -1323,18 +1291,9 @@ int denali_init(struct denali_nand_info *denali) 
		chip->buf_align = 16;

	}



	/*

	 * second stage of the NAND scan

	 * this stage requires information regarding ECC and

	 * bad block management.

	 */



	chip->bbt_options |= NAND_BBT_USE_FLASH;

	chip->bbt_options |= NAND_BBT_NO_OOB;



	chip->ecc.mode = NAND_ECC_HW_SYNDROME;



	/* no subpage writes on denali */

	chip->options |= NAND_NO_SUBPAGE_WRITE;



	ret = denali_ecc_setup(mtd, chip, denali);
@@ -1418,7 +1377,6 @@ disable_irq: 
}

EXPORT_SYMBOL(denali_init);



/* driver exit point */

void denali_remove(struct denali_nand_info *denali)

{

	struct mtd_info *mtd = nand_to_mtd(&denali->nand);

drivers/mtd/nand/denali.h

+8 −16
Original line number Diff line number Diff line
@@ -10,11 +10,6 @@ 
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for

 * more details.

 *

 * You should have received a copy of the GNU General Public License along with

 * this program; if not, write to the Free Software Foundation, Inc.,

 * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.

 *

 */



#ifndef __DENALI_H__
@@ -310,22 +305,19 @@ struct denali_nand_info { 
	struct device *dev;

	void __iomem *reg;		/* Register Interface */

	void __iomem *host;		/* Host Data/Command Interface */



	/* elements used by ISR */

	struct completion complete;

	spinlock_t irq_lock;

	uint32_t irq_mask;

	uint32_t irq_status;

	spinlock_t irq_lock;		/* protect irq_mask and irq_status */

	u32 irq_mask;			/* interrupts we are waiting for */

	u32 irq_status;			/* interrupts that have happened */

	int irq;



	void *buf;

	void *buf;			/* for syndrome layout conversion */

	dma_addr_t dma_addr;

	int dma_avail;

	int dma_avail;			/* can support DMA? */

	int devs_per_cs;		/* devices connected in parallel */

	int oob_skip_bytes;

	int oob_skip_bytes;		/* number of bytes reserved for BBM */

	int max_banks;

	unsigned int revision;

	unsigned int caps;

	unsigned int revision;		/* IP revision */

	unsigned int caps;		/* IP capability (or quirk) */

	const struct nand_ecc_caps *ecc_caps;

};

drivers/mtd/nand/denali_dt.c

+0 −1
Original line number Diff line number Diff line
@@ -156,7 +156,6 @@ static struct platform_driver denali_dt_driver = { 
		.of_match_table	= denali_nand_dt_ids,

	},

};



module_platform_driver(denali_dt_driver);



MODULE_LICENSE("GPL");

drivers/mtd/nand/denali_pci.c

+0 −2
Original line number Diff line number Diff line
@@ -109,7 +109,6 @@ failed_remap_reg: 
	return ret;

}



/* driver exit point */

static void denali_pci_remove(struct pci_dev *dev)

{

	struct denali_nand_info *denali = pci_get_drvdata(dev);
@@ -125,5 +124,4 @@ static struct pci_driver denali_pci_driver = { 
	.probe = denali_pci_probe,

	.remove = denali_pci_remove,

};



module_pci_driver(denali_pci_driver);

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