On Sun, Aug 27, 2023 at 4:40 AM Serge Semin [off-list ref] wrote:

On Thu, Aug 24, 2023 at 08:50:11PM +0800, Keguang Zhang wrote:

quoted

This glue driver is created based on the arch-code
implemented earlier with the platform-specific settings.

Use syscon for SYSCON register access.

Partially based on the previous work by Serge Semin.

Signed-off-by: Keguang Zhang <keguang.zhang@gmail.com>
---
V2 -> V3: Determine the device ID by physical
          base address(suggested by Serge Semin)
          Use regmap instead of regmap fields
          Use syscon_regmap_lookup_by_phandle()
          Some minor fixes
V1 -> V2: Fix the build errors due to CONFIG_OF being unset
          Change struct reg_field definitions to const
          Rename the syscon property to "loongson,dwmac-syscon"
          Add MII PHY mode for LS1C

 drivers/net/ethernet/stmicro/stmmac/Kconfig   |  11 +
 drivers/net/ethernet/stmicro/stmmac/Makefile  |   1 +
 .../ethernet/stmicro/stmmac/dwmac-loongson1.c | 240 ++++++++++++++++++
 3 files changed, 252 insertions(+)
 create mode 100644 drivers/net/ethernet/stmicro/stmmac/dwmac-loongson1.c

diff --git a/drivers/net/ethernet/stmicro/stmmac/Kconfig b/drivers/net/ethernet/stmicro/stmmac/Kconfig
index 06c6871f8788..a2b9e289aa36 100644
--- a/drivers/net/ethernet/stmicro/stmmac/Kconfig
+++ b/drivers/net/ethernet/stmicro/stmmac/Kconfig

@@ -239,6 +239,17 @@ config DWMAC_INTEL_PLAT
        the stmmac device driver. This driver is used for the Intel Keem Bay
        SoC.

+config DWMAC_LOONGSON1
+     tristate "Loongson1 GMAC support"
+     default MACH_LOONGSON32
+     depends on OF && (MACH_LOONGSON32 || COMPILE_TEST)
+     help
+       Support for ethernet controller on Loongson1 SoC.
+
+       This selects Loongson1 SoC glue layer support for the stmmac
+       device driver. This driver is used for Loongson1-based boards
+       like Loongson LS1B/LS1C.
+
 config DWMAC_TEGRA
      tristate "NVIDIA Tegra MGBE support"
      depends on ARCH_TEGRA || COMPILE_TEST

diff --git a/drivers/net/ethernet/stmicro/stmmac/Makefile b/drivers/net/ethernet/stmicro/stmmac/Makefile
index 5b57aee19267..80e598bd4255 100644
--- a/drivers/net/ethernet/stmicro/stmmac/Makefile
+++ b/drivers/net/ethernet/stmicro/stmmac/Makefile

@@ -29,6 +29,7 @@ obj-$(CONFIG_DWMAC_SUNXI)   += dwmac-sunxi.o
 obj-$(CONFIG_DWMAC_SUN8I)    += dwmac-sun8i.o
 obj-$(CONFIG_DWMAC_DWC_QOS_ETH)      += dwmac-dwc-qos-eth.o
 obj-$(CONFIG_DWMAC_INTEL_PLAT)       += dwmac-intel-plat.o
+obj-$(CONFIG_DWMAC_LOONGSON1)        += dwmac-loongson1.o
 obj-$(CONFIG_DWMAC_GENERIC)  += dwmac-generic.o
 obj-$(CONFIG_DWMAC_IMX8)     += dwmac-imx.o
 obj-$(CONFIG_DWMAC_TEGRA)    += dwmac-tegra.o

diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac-loongson1.c b/drivers/net/ethernet/stmicro/stmmac/dwmac-loongson1.c
new file mode 100644
index 000000000000..347d842141e4
--- /dev/null
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac-loongson1.c

@@ -0,0 +1,240 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Loongson-1 DWMAC glue layer
+ *
+ * Copyright (C) 2011-2023 Keguang Zhang <keguang.zhang@gmail.com>
+ */
+
+#include <linux/mfd/syscon.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/phy.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+
+#include "stmmac.h"
+#include "stmmac_platform.h"
+
+#define LS1X_GMAC0_BASE              (0xe10000)

quoted

+#define LS1X_GMAC1_BASE              (0xe20000)

If LS1C doesn't have the second GMAC then what about changing the
macros name to LS1B_GMAC1_BASE?

quoted

+
+/* Loongson-1 SYSCON Registers */
+#define LS1X_SYSCON0         (0x0)
+#define LS1X_SYSCON1         (0x4)
+
+/* Loongson-1B SYSCON Register Bits */

quoted

+#define GMAC1_USE_UART1              BIT(4)
+#define GMAC1_USE_UART0              BIT(3)
+
+#define GMAC1_SHUT           BIT(13)
+#define GMAC0_SHUT           BIT(12)
+
+#define GMAC1_USE_TXCLK              BIT(3)
+#define GMAC0_USE_TXCLK              BIT(2)
+#define GMAC1_USE_PWM23              BIT(1)
+#define GMAC0_USE_PWM01              BIT(0)
+
+/* Loongson-1C SYSCON Register Bits */
+#define GMAC_SHUT            BIT(6)
+
+#define PHY_INTF_SELI                GENMASK(30, 28)

IMO having the SoC-specific prefixes (LS1B_ and LS1C_) in these names
would make the driver a bit more readable. But it's up to you to
decide.

quoted

+#define PHY_INTF_SELI_SHIFT  28

Use FIELD_PREP():
#define PHY_INTF_MII                    FIELD_PREP(PHY_INTF_SELI, 0)
#define PHY_INTF_RMII                   FIELD_PREP(PHY_INTF_SELI, 4)

quoted

+
+struct ls1x_dwmac_syscon {
+     int (*syscon_init)(struct plat_stmmacenet_data *plat);
+};

This struct is redundant. See further for details.

quoted

+
+struct ls1x_dwmac {

quoted

+     unsigned long reg_base;

this field

quoted

+     struct device *dev;

quoted

+     struct plat_stmmacenet_data *plat_dat;
+     const struct ls1x_dwmac_syscon *syscon;

and these fields are also redundant. See further for details.

quoted

+     struct regmap *regmap;
+};
+
+static int ls1b_dwmac_syscon_init(struct plat_stmmacenet_data *plat)
+{
+     struct ls1x_dwmac *dwmac = plat->bsp_priv;
+     struct regmap *regmap = dwmac->regmap;
+

quoted

+     if ((dwmac->reg_base & LS1X_GMAC0_BASE) == LS1X_GMAC0_BASE) {

Is it necessary to bitwise-and-ing? What if LS1X_GMAC0_BASE would be
just a full physical base address? Then you'll be able to just compare
the base addresses.

quoted

+             switch (plat->phy_interface) {
+             case PHY_INTERFACE_MODE_RGMII_ID:
+                     regmap_update_bits(regmap, LS1X_SYSCON0,
+                                        GMAC0_USE_TXCLK | GMAC0_USE_PWM01,
+                                        0);
+                     break;
+             case PHY_INTERFACE_MODE_MII:
+                     regmap_update_bits(regmap, LS1X_SYSCON0,
+                                        GMAC0_USE_TXCLK | GMAC0_USE_PWM01,
+                                        GMAC0_USE_TXCLK | GMAC0_USE_PWM01);
+                     break;
+             default:
+                     dev_err(dwmac->dev, "Unsupported PHY mode %u\n",
+                             plat->phy_interface);
+                     return -EOPNOTSUPP;
+             }
+
+             regmap_update_bits(regmap, LS1X_SYSCON0, GMAC0_SHUT, 0);

quoted

+     }
+
+     if ((dwmac->reg_base & LS1X_GMAC1_BASE) == LS1X_GMAC1_BASE) {

else if?

quoted

+             regmap_update_bits(regmap, LS1X_SYSCON0,
+                                GMAC1_USE_UART1 | GMAC1_USE_UART0,
+                                GMAC1_USE_UART1 | GMAC1_USE_UART0);
+
+             switch (plat->phy_interface) {
+             case PHY_INTERFACE_MODE_RGMII_ID:
+                     regmap_update_bits(regmap, LS1X_SYSCON1,
+                                        GMAC1_USE_TXCLK | GMAC1_USE_PWM23,
+                                        0);
+
+                     break;
+             case PHY_INTERFACE_MODE_MII:
+                     regmap_update_bits(regmap, LS1X_SYSCON1,
+                                        GMAC1_USE_TXCLK | GMAC1_USE_PWM23,
+                                        GMAC1_USE_TXCLK | GMAC1_USE_PWM23);
+                     break;
+             default:
+                     dev_err(dwmac->dev, "Unsupported PHY mode %u\n",
+                             plat->phy_interface);
+                     return -EOPNOTSUPP;
+             }
+
+             regmap_update_bits(regmap, LS1X_SYSCON1, GMAC1_SHUT, 0);

quoted

+     }

else {
        dev_err(...)
        return -EINVAL;
}
?

* unless you have some more DW GMACs on the SoC which don't require the
syscon setups.

quoted

+
+     return 0;
+}
+
+static int ls1c_dwmac_syscon_init(struct plat_stmmacenet_data *plat)
+{
+     struct ls1x_dwmac *dwmac = plat->bsp_priv;
+     struct regmap *regmap = dwmac->regmap;
+
+     switch (plat->phy_interface) {
+     case PHY_INTERFACE_MODE_MII:

quoted

+             regmap_update_bits(regmap, LS1X_SYSCON1, PHY_INTF_SELI, 0);

                regmap_update_bits(regmap, LS1X_SYSCON1, PHY_INTF_SELI,
                                   PHY_INTF_MII);

quoted

+             break;
+     case PHY_INTERFACE_MODE_RMII:

quoted

+             regmap_update_bits(regmap, LS1X_SYSCON1, PHY_INTF_SELI,
+                                4 << PHY_INTF_SELI_SHIFT);

                regmap_update_bits(regmap, LS1X_SYSCON1, PHY_INTF_SELI,
                                   PHY_INTF_RMII);

quoted

+             break;
+     default:
+             dev_err(dwmac->dev, "Unsupported PHY-mode %u\n",
+                     plat->phy_interface);
+             return -EOPNOTSUPP;
+     }
+
+     regmap_update_bits(regmap, LS1X_SYSCON0, GMAC0_SHUT, 0);
+
+     return 0;
+}
+

quoted

+static const struct ls1x_dwmac_syscon ls1b_dwmac_syscon = {
+     .syscon_init = ls1b_dwmac_syscon_init,
+};
+
+static const struct ls1x_dwmac_syscon ls1c_dwmac_syscon = {
+     .syscon_init = ls1c_dwmac_syscon_init,
+};

This can be dropped. See the next comment for details.

quoted

+
+static int ls1x_dwmac_init(struct platform_device *pdev, void *priv)
+{
+     struct ls1x_dwmac *dwmac = priv;
+     struct resource *res;
+     int ret;
+

quoted

+     res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+     if (!res) {
+             dev_err(&pdev->dev, "Could not get IO_MEM resources\n");
+             return -EINVAL;
+     }
+     dwmac->reg_base = (unsigned long)res->start;

What about moving this to ls1b_dwmac_syscon_init() seeing it's used
for LS1B only? Thus you won't need to have the reg_base defined in the
private data and can get rid from the ls1x_dwmac_init() method setting
the ls1b_dwmac_syscon_init() and ls1c_dwmac_syscon_init() pointers
directly to the device match data.

quoted

+
+     if (dwmac->syscon->syscon_init) {
+             ret = dwmac->syscon->syscon_init(dwmac->plat_dat);
+             if (ret)
+                     return ret;
+     }
+
+     return 0;
+}
+
+static int ls1x_dwmac_probe(struct platform_device *pdev)
+{
+     struct plat_stmmacenet_data *plat_dat;
+     struct stmmac_resources stmmac_res;
+     struct regmap *regmap;
+     struct ls1x_dwmac *dwmac;

quoted

+     const struct ls1x_dwmac_syscon *syscon;

This can be replaced with just
int (*init)(struct platform_device *pdev, void *priv);

quoted

+     int ret;
+
+     ret = stmmac_get_platform_resources(pdev, &stmmac_res);
+     if (ret)
+             return ret;
+
+     /* Probe syscon */
+     regmap = syscon_regmap_lookup_by_phandle(pdev->dev.of_node,
+                                              "loongson,ls1-syscon");
+     if (IS_ERR(regmap)) {

quoted

+             ret = PTR_ERR(regmap);
+             dev_err(&pdev->dev, "Unable to map syscon: %d\n", ret);
+             return ret;

return dev_err_probe(&pdev->dev, PTR_ERR(regmap), "Unable to find syscon\n");

quoted

+     }
+

quoted

+     syscon = of_device_get_match_data(&pdev->dev);

init = of_device_get_match_data(&pdev->dev);

quoted

+     if (!syscon) {
+             dev_err(&pdev->dev, "No of match data provided\n");
+             return -EINVAL;
+     }
+
+     dwmac = devm_kzalloc(&pdev->dev, sizeof(*dwmac), GFP_KERNEL);
+     if (!dwmac)
+             return -ENOMEM;
+
+     plat_dat = stmmac_probe_config_dt(pdev, stmmac_res.mac);
+     if (IS_ERR(plat_dat)) {
+             dev_err(&pdev->dev, "dt configuration failed\n");
+             return PTR_ERR(plat_dat);
+     }
+
+     plat_dat->bsp_priv = dwmac;

quoted

+     plat_dat->init = ls1x_dwmac_init;

plat_dat->init = init;

quoted

+     dwmac->dev = &pdev->dev;
+     dwmac->plat_dat = plat_dat;
+     dwmac->syscon = syscon;
+     dwmac->regmap = regmap;
+
+     ret = stmmac_pltfr_probe(pdev, plat_dat, &stmmac_res);
+     if (ret)
+             goto err_remove_config_dt;
+
+     return 0;
+
+err_remove_config_dt:
+     stmmac_remove_config_dt(pdev, plat_dat);
+
+     return ret;
+}
+
+static const struct of_device_id ls1x_dwmac_match[] = {

quoted

+     { .compatible = "loongson,ls1b-gmac", .data = &ls1b_dwmac_syscon, },
+     { .compatible = "loongson,ls1c-emac", .data = &ls1c_dwmac_syscon, },

{ .compatible = "loongson,ls1b-gmac", .data = &ls1b_dwmac_syscon_init, },
{ .compatible = "loongson,ls1c-emac", .data = &ls1c_dwmac_syscon_init, },

Thus you can simplify the driver by:
1. dropping ls1x_dwmac_syscon definition and its instances.
2. dropping three redundant fields from the ls1x_dwmac structure.
3. dropping the ls1x_dwmac_init() method.
Sounds like worth it.)

Note if no further driver update is planned then you can drop the
ls1x_dwmac->dev field too. Otherwise you can keep it seeing some of
the plat_stmmacenet_data data callbacks do have any device instance
passed.

All done in v4.
Thanks!

-Serge(y)

quoted

+     { }
+};
+MODULE_DEVICE_TABLE(of, ls1x_dwmac_match);
+
+static struct platform_driver ls1x_dwmac_driver = {
+     .probe = ls1x_dwmac_probe,
+     .remove_new = stmmac_pltfr_remove,
+     .driver = {
+             .name = "loongson1-dwmac",
+             .of_match_table = ls1x_dwmac_match,
+     },
+};
+module_platform_driver(ls1x_dwmac_driver);
+
+MODULE_AUTHOR("Keguang Zhang [off-list ref]");
+MODULE_DESCRIPTION("Loongson1 DWMAC glue layer");
+MODULE_LICENSE("GPL");
--
2.39.2

-- 
Best regards,

Keguang Zhang