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Message-ID: <20100511011638.GI2589@trinity.fluff.org>
Date: Tue, 11 May 2010 02:16:38 +0100
From: Ben Dooks <ben-linux@...ff.org>
To: Sebastien Jan <s-jan@...com>
Cc: netdev@...r.kernel.org, linux-omap@...r.kernel.org,
Abraham Arce <x0066660@...com>,
Ben Dooks <ben-linux@...ff.org>, Tristram.Ha@...rel.com
Subject: Re: [PATCH 2/4 v2] ks8851: Low level functions for read/write to
companion eeprom
On Wed, May 05, 2010 at 08:45:53PM +0200, Sebastien Jan wrote:
> Low-level functions provide 16bits words read and write capability
> to ks8851 companion eeprom.
Please use the eeprom interface that was added already
> Signed-off-by: Sebastien Jan <s-jan@...com>
> ---
> drivers/net/ks8851.c | 228 ++++++++++++++++++++++++++++++++++++++++++++++++++
> drivers/net/ks8851.h | 14 +++-
> 2 files changed, 241 insertions(+), 1 deletions(-)
>
> diff --git a/drivers/net/ks8851.c b/drivers/net/ks8851.c
> index a84e500..787f9df 100644
> --- a/drivers/net/ks8851.c
> +++ b/drivers/net/ks8851.c
> @@ -1044,6 +1044,234 @@ static const struct net_device_ops ks8851_netdev_ops = {
> .ndo_validate_addr = eth_validate_addr,
> };
>
> +/* Companion eeprom access */
> +
> +enum { /* EEPROM programming states */
> + EEPROM_CONTROL,
> + EEPROM_ADDRESS,
> + EEPROM_DATA,
> + EEPROM_COMPLETE
> +};
> +
> +/**
> + * ks8851_eeprom_read - read a 16bits word in ks8851 companion EEPROM
> + * @dev: The network device the PHY is on.
> + * @addr: EEPROM address to read
> + *
> + * eeprom_size: used to define the data coding length. Can be changed
> + * through debug-fs.
> + *
> + * Programs a read on the EEPROM using ks8851 EEPROM SW access feature.
> + * Warning: The READ feature is not supported on ks8851 revision 0.
> + *
> + * Rough programming model:
> + * - on period start: set clock high and read value on bus
> + * - on period / 2: set clock low and program value on bus
> + * - start on period / 2
> + */
> +unsigned int ks8851_eeprom_read(struct net_device *dev, unsigned int addr)
> +{
> + struct ks8851_net *ks = netdev_priv(dev);
> + int eepcr;
> + int ctrl = EEPROM_OP_READ;
> + int state = EEPROM_CONTROL;
> + int bit_count = EEPROM_OP_LEN - 1;
> + unsigned int data = 0;
> + int dummy;
> + unsigned int addr_len;
> +
> + addr_len = (ks->eeprom_size == 128) ? 6 : 8;
> +
> + /* start transaction: chip select high, authorize write */
> + mutex_lock(&ks->lock);
> + eepcr = EEPCR_EESA | EEPCR_EESRWA;
> + ks8851_wrreg16(ks, KS_EEPCR, eepcr);
> + eepcr |= EEPCR_EECS;
> + ks8851_wrreg16(ks, KS_EEPCR, eepcr);
> + mutex_unlock(&ks->lock);
> +
> + while (state != EEPROM_COMPLETE) {
> + /* falling clock period starts... */
> + /* set EED_IO pin for control and address */
> + eepcr &= ~EEPCR_EEDO;
> + switch (state) {
> + case EEPROM_CONTROL:
> + eepcr |= ((ctrl >> bit_count) & 1) << 2;
> + if (bit_count-- <= 0) {
> + bit_count = addr_len - 1;
> + state = EEPROM_ADDRESS;
> + }
> + break;
> + case EEPROM_ADDRESS:
> + eepcr |= ((addr >> bit_count) & 1) << 2;
> + bit_count--;
> + break;
> + case EEPROM_DATA:
> + /* Change to receive mode */
> + eepcr &= ~EEPCR_EESRWA;
> + break;
> + }
> +
> + /* lower clock */
> + eepcr &= ~EEPCR_EESCK;
> +
> + mutex_lock(&ks->lock);
> + ks8851_wrreg16(ks, KS_EEPCR, eepcr);
> + mutex_unlock(&ks->lock);
> +
> + /* waitread period / 2 */
> + udelay(EEPROM_SK_PERIOD / 2);
> +
> + /* rising clock period starts... */
> +
> + /* raise clock */
> + mutex_lock(&ks->lock);
> + eepcr |= EEPCR_EESCK;
> + ks8851_wrreg16(ks, KS_EEPCR, eepcr);
> + mutex_unlock(&ks->lock);
> +
> + /* Manage read */
> + switch (state) {
> + case EEPROM_ADDRESS:
> + if (bit_count < 0) {
> + bit_count = EEPROM_DATA_LEN - 1;
> + state = EEPROM_DATA;
> + }
> + break;
> + case EEPROM_DATA:
> + mutex_lock(&ks->lock);
> + dummy = ks8851_rdreg16(ks, KS_EEPCR);
> + mutex_unlock(&ks->lock);
> + data |= ((dummy >> EEPCR_EESB_OFFSET) & 1) << bit_count;
> + if (bit_count-- <= 0)
> + state = EEPROM_COMPLETE;
> + break;
> + }
> +
> + /* wait period / 2 */
> + udelay(EEPROM_SK_PERIOD / 2);
> + }
> +
> + /* close transaction */
> + mutex_lock(&ks->lock);
> + eepcr &= ~EEPCR_EECS;
> + ks8851_wrreg16(ks, KS_EEPCR, eepcr);
> + eepcr = 0;
> + ks8851_wrreg16(ks, KS_EEPCR, eepcr);
> + mutex_unlock(&ks->lock);
> +
> + return data;
> +}
> +
> +/**
> + * ks8851_eeprom_write - write a 16bits word in ks8851 companion EEPROM
> + * @dev: The network device the PHY is on.
> + * @op: operand (can be WRITE, EWEN, EWDS)
> + * @addr: EEPROM address to write
> + * @data: data to write
> + *
> + * eeprom_size: used to define the data coding length. Can be changed
> + * through debug-fs.
> + *
> + * Programs a write on the EEPROM using ks8851 EEPROM SW access feature.
> + *
> + * Note that a write enable is required before writing data.
> + *
> + * Rough programming model:
> + * - on period start: set clock high
> + * - on period / 2: set clock low and program value on bus
> + * - start on period / 2
> + */
> +void ks8851_eeprom_write(struct net_device *dev, unsigned int op,
> + unsigned int addr, unsigned int data)
> +{
> + struct ks8851_net *ks = netdev_priv(dev);
> + int eepcr;
> + int state = EEPROM_CONTROL;
> + int bit_count = EEPROM_OP_LEN - 1;
> + unsigned int addr_len;
> +
> + addr_len = (ks->eeprom_size == 128) ? 6 : 8;
> +
> + switch (op) {
> + case EEPROM_OP_EWEN:
> + addr = 0x30;
> + break;
> + case EEPROM_OP_EWDS:
> + addr = 0;
> + break;
> + }
> +
> + /* start transaction: chip select high, authorize write */
> + mutex_lock(&ks->lock);
> + eepcr = EEPCR_EESA | EEPCR_EESRWA;
> + ks8851_wrreg16(ks, KS_EEPCR, eepcr);
> + eepcr |= EEPCR_EECS;
> + ks8851_wrreg16(ks, KS_EEPCR, eepcr);
> + mutex_unlock(&ks->lock);
> +
> + while (state != EEPROM_COMPLETE) {
> + /* falling clock period starts... */
> + /* set EED_IO pin for control and address */
> + eepcr &= ~EEPCR_EEDO;
> + switch (state) {
> + case EEPROM_CONTROL:
> + eepcr |= ((op >> bit_count) & 1) << 2;
> + if (bit_count-- <= 0) {
> + bit_count = addr_len - 1;
> + state = EEPROM_ADDRESS;
> + }
> + break;
> + case EEPROM_ADDRESS:
> + eepcr |= ((addr >> bit_count) & 1) << 2;
> + if (bit_count-- <= 0) {
> + if (op == EEPROM_OP_WRITE) {
> + bit_count = EEPROM_DATA_LEN - 1;
> + state = EEPROM_DATA;
> + } else {
> + state = EEPROM_COMPLETE;
> + }
> + }
> + break;
> + case EEPROM_DATA:
> + eepcr |= ((data >> bit_count) & 1) << 2;
> + if (bit_count-- <= 0)
> + state = EEPROM_COMPLETE;
> + break;
> + }
> +
> + /* lower clock */
> + eepcr &= ~EEPCR_EESCK;
> +
> + mutex_lock(&ks->lock);
> + ks8851_wrreg16(ks, KS_EEPCR, eepcr);
> + mutex_unlock(&ks->lock);
> +
> + /* wait period / 2 */
> + udelay(EEPROM_SK_PERIOD / 2);
> +
> + /* rising clock period starts... */
> +
> + /* raise clock */
> + eepcr |= EEPCR_EESCK;
> + mutex_lock(&ks->lock);
> + ks8851_wrreg16(ks, KS_EEPCR, eepcr);
> + mutex_unlock(&ks->lock);
> +
> + /* wait period / 2 */
> + udelay(EEPROM_SK_PERIOD / 2);
> + }
> +
> + /* close transaction */
> + mutex_lock(&ks->lock);
> + eepcr &= ~EEPCR_EECS;
> + ks8851_wrreg16(ks, KS_EEPCR, eepcr);
> + eepcr = 0;
> + ks8851_wrreg16(ks, KS_EEPCR, eepcr);
> + mutex_unlock(&ks->lock);
> +
> +}
> +
> /* ethtool support */
>
> static void ks8851_get_drvinfo(struct net_device *dev,
> diff --git a/drivers/net/ks8851.h b/drivers/net/ks8851.h
> index f52c312..537fb06 100644
> --- a/drivers/net/ks8851.h
> +++ b/drivers/net/ks8851.h
> @@ -25,12 +25,24 @@
> #define OBCR_ODS_16mA (1 << 6)
>
> #define KS_EEPCR 0x22
> +#define EEPCR_EESRWA (1 << 5)
> #define EEPCR_EESA (1 << 4)
> -#define EEPCR_EESB (1 << 3)
> +#define EEPCR_EESB_OFFSET 3
> +#define EEPCR_EESB (1 << EEPCR_EESB_OFFSET)
> #define EEPCR_EEDO (1 << 2)
> #define EEPCR_EESCK (1 << 1)
> #define EEPCR_EECS (1 << 0)
>
> +#define EEPROM_OP_LEN 3 /* bits:*/
> +#define EEPROM_OP_READ 0x06
> +#define EEPROM_OP_EWEN 0x04
> +#define EEPROM_OP_WRITE 0x05
> +#define EEPROM_OP_EWDS 0x14
> +
> +#define EEPROM_DATA_LEN 16 /* 16 bits EEPROM */
> +#define EEPROM_WRITE_TIME 4 /* wrt ack time in ms */
> +#define EEPROM_SK_PERIOD 400 /* in us */
> +
> #define KS_MBIR 0x24
> #define MBIR_TXMBF (1 << 12)
> #define MBIR_TXMBFA (1 << 11)
> --
> 1.6.3.3
>
--
--
Ben
Q: What's a light-year?
A: One-third less calories than a regular year.
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