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net: phy: microchip_t1s: replace read-modify-write code with phy_modify_mmd

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Replace read-modify-write code in the lan867x_config_init function to
avoid handling data type mismatch and to simplify the code.

Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Parthiban Veerasooran <Parthiban.Veerasooran@microchip.com>
Reviewed-by: Ramón Nordin Rodriguez <ramon.nordin.rodriguez@ferroamp.se>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
This commit is contained in:
Parthiban Veerasooran 2023-05-26 20:53:44 +05:30 committed by Paolo Abeni
parent ca33db4a86
commit 221a534480
1 changed files with 13 additions and 28 deletions
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41
drivers/net/phy/microchip_t1s.c
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@ -31,19 +31,19 @@
* W 0x1F 0x0099 0x7F80 ------
*/
static const int lan867x_fixup_registers[12] = {
static const u32 lan867x_fixup_registers[12] = {
0x00D0, 0x00D1, 0x0084, 0x0085,
0x008A, 0x0087, 0x0088, 0x008B,
0x0080, 0x00F1, 0x0096, 0x0099,
};
static const int lan867x_fixup_values[12] = {
static const u16 lan867x_fixup_values[12] = {
0x0002, 0x0000, 0x3380, 0x0006,
0xC000, 0x801C, 0x033F, 0x0404,
0x0600, 0x2400, 0x2000, 0x7F80,
};
static const int lan867x_fixup_masks[12] = {
static const u16 lan867x_fixup_masks[12] = {
0x0E03, 0x0300, 0xFFC0, 0x000F,
0xF800, 0x801C, 0x1FFF, 0xFFFF,
0x0600, 0x7F00, 0x2000, 0xFFFF,
@ -51,35 +51,20 @@ static const int lan867x_fixup_masks[12] = {
static int lan867x_config_init(struct phy_device *phydev)
{
/* HW quirk: Microchip states in the application note (AN1699) for the phy
* that a set of read-modify-write (rmw) operations has to be performed
* on a set of seemingly magic registers.
* The result of these operations is just described as 'optimal performance'
* Microchip gives no explanation as to what these mmd regs do,
* in fact they are marked as reserved in the datasheet.
* It is unclear if phy_modify_mmd would be safe to use or if a write
* really has to happen to each register.
* In order to exactly conform to what is stated in the AN phy_write_mmd is
* used, which might then write the same value back as read + modified.
*/
int reg_value;
int err;
int reg;
/* Read-Modified Write Pseudocode (from AN1699)
* current_val = read_register(mmd, addr) // Read current register value
* new_val = current_val AND (NOT mask) // Clear bit fields to be written
* new_val = new_val OR value // Set bits
* write_register(mmd, addr, new_val) // Write back updated register value
/* Reference to AN1699
* https://ww1.microchip.com/downloads/aemDocuments/documents/AIS/ProductDocuments/SupportingCollateral/AN-LAN8670-1-2-config-60001699.pdf
* AN1699 says Read, Modify, Write, but the Write is not required if the
* register already has the required value. So it is safe to use
* phy_modify_mmd here.
*/
for (int i = 0; i < ARRAY_SIZE(lan867x_fixup_registers); i++) {
reg = lan867x_fixup_registers[i];
reg_value = phy_read_mmd(phydev, MDIO_MMD_VEND2, reg);
reg_value &= ~lan867x_fixup_masks[i];
reg_value |= lan867x_fixup_values[i];
err = phy_write_mmd(phydev, MDIO_MMD_VEND2, reg, reg_value);
if (err != 0)
err = phy_modify_mmd(phydev, MDIO_MMD_VEND2,
lan867x_fixup_registers[i],
lan867x_fixup_masks[i],
lan867x_fixup_values[i]);
if (err)
return err;
}