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mtd: nand: denali: clean up comments
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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: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
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Masahiro Yamada authored and Boris Brezillon committed Sep 22, 2017
1 parent 8e4cbf7 commit 8582a03
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Showing 4 changed files with 13 additions and 66 deletions.
52 changes: 5 additions & 47 deletions drivers/mtd/nand/denali.c
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Original file line number Diff line number Diff line change
Expand Up @@ -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>
Expand Down Expand Up @@ -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);
Expand Down Expand Up @@ -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))
Expand Down Expand Up @@ -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;
Expand Down Expand Up @@ -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;
Expand Down Expand Up @@ -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) {
Expand All @@ -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;
Expand All @@ -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;
Expand All @@ -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);
Expand Down Expand Up @@ -1418,7 +1377,6 @@ int denali_init(struct denali_nand_info *denali)
}
EXPORT_SYMBOL(denali_init);

/* driver exit point */
void denali_remove(struct denali_nand_info *denali)
{
struct mtd_info *mtd = nand_to_mtd(&denali->nand);
Expand Down
24 changes: 8 additions & 16 deletions drivers/mtd/nand/denali.h
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Original file line number Diff line number Diff line change
Expand Up @@ -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__
Expand Down Expand Up @@ -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;
};

Expand Down
1 change: 0 additions & 1 deletion drivers/mtd/nand/denali_dt.c
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Original file line number Diff line number Diff line change
Expand Up @@ -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");
Expand Down
2 changes: 0 additions & 2 deletions drivers/mtd/nand/denali_pci.c
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Original file line number Diff line number Diff line change
Expand Up @@ -109,7 +109,6 @@ static int denali_pci_probe(struct pci_dev *dev, const struct pci_device_id *id)
return ret;
}

/* driver exit point */
static void denali_pci_remove(struct pci_dev *dev)
{
struct denali_nand_info *denali = pci_get_drvdata(dev);
Expand All @@ -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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