[PATCH 5.10 169/545] i2c: npcm: Remove own slave addresses 2:10

Greg Kroah-Hartman
2022-08-19T16:06:45Z

From: Tali Perry <tali.perry1@gmail.com>

[ Upstream commit 47d506d1a28fd10a9fb1f33df5622d88fae72095 ]

NPCM can support up to 10 own slave addresses. In practice, only one
address is actually being used. In order to access addresses 2 and above,
need to switch register banks. The switch needs spinlock.
To avoid using spinlock for this useless feature removed support of SA >=
2. Also fix returned slave event enum.

Remove some comment since the bank selection is not required. The bank
selection is not required since the supported slave addresses are reduced.

Fixes: 56a1485b102e ("i2c: npcm7xx: Add Nuvoton NPCM I2C controller driver")
Signed-off-by: Tali Perry <tali.perry1@gmail.com>
Signed-off-by: Tyrone Ting <kfting@nuvoton.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/i2c/busses/i2c-npcm7xx.c | 41 +++++++++++++-------------------
1 file changed, 16 insertions(+), 25 deletions(-)

diff --git a/drivers/i2c/busses/i2c-npcm7xx.c b/drivers/i2c/busses/i2c-npcm7xx.c
index d9ac62c1ac25..ab31e7fb4cc9 100644
--- a/drivers/i2c/busses/i2c-npcm7xx.c
+++ b/drivers/i2c/busses/i2c-npcm7xx.c
@@ -123,11 +123,11 @@ enum i2c_addr {
* Since the addr regs are sprinkled all over the address space,
* use this array to get the address or each register.
*/
-#define I2C_NUM_OWN_ADDR 10
+#define I2C_NUM_OWN_ADDR 2
+#define I2C_NUM_OWN_ADDR_SUPPORTED 2
+
static const int npcm_i2caddr[I2C_NUM_OWN_ADDR] = {
- NPCM_I2CADDR1, NPCM_I2CADDR2, NPCM_I2CADDR3, NPCM_I2CADDR4,
- NPCM_I2CADDR5, NPCM_I2CADDR6, NPCM_I2CADDR7, NPCM_I2CADDR8,
- NPCM_I2CADDR9, NPCM_I2CADDR10,
+ NPCM_I2CADDR1, NPCM_I2CADDR2,
};
#endif

@@ -391,14 +391,10 @@ static void npcm_i2c_disable(struct npcm_i2c *bus)
#if IS_ENABLED(CONFIG_I2C_SLAVE)
int i;

- /* select bank 0 for I2C addresses */
- npcm_i2c_select_bank(bus, I2C_BANK_0);
-
/* Slave addresses removal */
- for (i = I2C_SLAVE_ADDR1; i < I2C_NUM_OWN_ADDR; i++)
+ for (i = I2C_SLAVE_ADDR1; i < I2C_NUM_OWN_ADDR_SUPPORTED; i++)
iowrite8(0, bus->reg + npcm_i2caddr[i]);

- npcm_i2c_select_bank(bus, I2C_BANK_1);
#endif
/* Disable module */
i2cctl2 = ioread8(bus->reg + NPCM_I2CCTL2);
@@ -603,8 +599,7 @@ static int npcm_i2c_slave_enable(struct npcm_i2c *bus, enum i2c_addr addr_type,
i2cctl1 &= ~NPCM_I2CCTL1_GCMEN;
iowrite8(i2cctl1, bus->reg + NPCM_I2CCTL1);
return 0;
- }
- if (addr_type == I2C_ARP_ADDR) {
+ } else if (addr_type == I2C_ARP_ADDR) {
i2cctl3 = ioread8(bus->reg + NPCM_I2CCTL3);
if (enable)
i2cctl3 |= I2CCTL3_ARPMEN;
@@ -613,16 +608,16 @@ static int npcm_i2c_slave_enable(struct npcm_i2c *bus, enum i2c_addr addr_type,
iowrite8(i2cctl3, bus->reg + NPCM_I2CCTL3);
return 0;
}
+ if (addr_type > I2C_SLAVE_ADDR2 && addr_type <= I2C_SLAVE_ADDR10)
+ dev_err(bus->dev, "try to enable more than 2 SA not supported\n");
+
if (addr_type >= I2C_ARP_ADDR)
return -EFAULT;
- /* select bank 0 for address 3 to 10 */
- if (addr_type > I2C_SLAVE_ADDR2)
- npcm_i2c_select_bank(bus, I2C_BANK_0);
+
/* Set and enable the address */
iowrite8(sa_reg, bus->reg + npcm_i2caddr[addr_type]);
npcm_i2c_slave_int_enable(bus, enable);
- if (addr_type > I2C_SLAVE_ADDR2)
- npcm_i2c_select_bank(bus, I2C_BANK_1);
+
return 0;
}
#endif
@@ -843,15 +838,11 @@ static u8 npcm_i2c_get_slave_addr(struct npcm_i2c *bus, enum i2c_addr addr_type)
{
u8 slave_add;

- /* select bank 0 for address 3 to 10 */
- if (addr_type > I2C_SLAVE_ADDR2)
- npcm_i2c_select_bank(bus, I2C_BANK_0);
+ if (addr_type > I2C_SLAVE_ADDR2 && addr_type <= I2C_SLAVE_ADDR10)
+ dev_err(bus->dev, "get slave: try to use more than 2 SA not supported\n");

slave_add = ioread8(bus->reg + npcm_i2caddr[(int)addr_type]);

- if (addr_type > I2C_SLAVE_ADDR2)
- npcm_i2c_select_bank(bus, I2C_BANK_1);
-
return slave_add;
}

@@ -861,12 +852,12 @@ static int npcm_i2c_remove_slave_addr(struct npcm_i2c *bus, u8 slave_add)

/* Set the enable bit */
slave_add |= 0x80;
- npcm_i2c_select_bank(bus, I2C_BANK_0);
- for (i = I2C_SLAVE_ADDR1; i < I2C_NUM_OWN_ADDR; i++) {
+
+ for (i = I2C_SLAVE_ADDR1; i < I2C_NUM_OWN_ADDR_SUPPORTED; i++) {
if (ioread8(bus->reg + npcm_i2caddr[i]) == slave_add)
iowrite8(0, bus->reg + npcm_i2caddr[i]);
}
- npcm_i2c_select_bank(bus, I2C_BANK_1);
+
return 0;
}

--
2.35.1