[U-Boot] [PATCH 08/12] aspeed/ast2500: Add SDRAM MC driver

Maxim Sloyko
2017-01-18T20:16:54Z

On Sat, Jan 14, 2017 at 9:14 AM, Simon Glass <sjg@chromium.org> wrote:

> Hi Maxim,
>
> On 4 January 2017 at 12:46, Maxim Sloyko <maxims@google.com> wrote:
> > The driver is very ast2500 specific and is completely incompatible
>
> ast2500-specific
>
> > with previous versions of the chip.
> >
> > The memory controller is very poorly documented by Aspeed in the
> > datasheet, with any mention of the whole range of registers missing. The
> > initialization procedure has been basically taken from Aspeed SDK, where
> > it is implemented in assembly and rewritten in C, with very limited
> > understanding of what exacly it is doing.
>
> Here I think you mean:
> where
> it is implemented in assembly. Here it is rewritten in C, with very
> limited
> understanding of what exactly (spelling) it is doing.
>

Fixed the message.

>
>
> >
> > Signed-off-by: Maxim Sloyko <maxims@google.com>
> > ---
> >
> > arch/arm/include/asm/arch-aspeed/sdram_ast2500.h | 133 +++++++
> > arch/arm/mach-aspeed/ast2500/Makefile | 2 +-
> > arch/arm/mach-aspeed/ast2500/sdram_ast2500.c | 443
> +++++++++++++++++++++++
> > 3 files changed, 577 insertions(+), 1 deletion(-)
> > create mode 100644 arch/arm/include/asm/arch-aspeed/sdram_ast2500.h
> > create mode 100644 arch/arm/mach-aspeed/ast2500/sdram_ast2500.c
> >
> > diff --git a/arch/arm/include/asm/arch-aspeed/sdram_ast2500.h
> b/arch/arm/include/asm/arch-aspeed/sdram_ast2500.h
> > new file mode 100644
> > index 0000000000..ca70898df6
> > --- /dev/null
> > +++ b/arch/arm/include/asm/arch-aspeed/sdram_ast2500.h
> > @@ -0,0 +1,133 @@
> > +#ifndef _ASM_ARCH_SDRAM_AST2500_H
> > +#define _ASM_ARCH_SDRAM_AST2500_H
> > +
> > +#define SDRAM_UNLOCK_KEY 0xfc600309
> > +#define SDRAM_VIDEO_UNLOCK_KEY 0x2003000f
> > +
> > +#define SDRAM_PCR_CKE_EN (1 << 0)
> > +#define SDRAM_PCR_AUTOPWRDN_EN (1 << 1)
> > +#define SDRAM_PCR_CKE_DELAY_SHIFT 4
> > +#define SDRAM_PCR_CKE_DELAY_MASK 7
> > +#define SDRAM_PCR_RESETN_DIS (1 << 7)
> > +#define SDRAM_PCR_ODT_EN (1 << 8)
> > +#define SDRAM_PCR_ODT_AUTO_ON (1 << 10)
> > +#define SDRAM_PCR_ODT_EXT_EN (1 << 11)
> > +#define SDRAM_PCR_TCKE_PW_SHIFT 12
> > +#define SDRAM_PCR_TCKE_PW_MASK 7
> > +#define SDRAM_PCR_RGAP_CTRL_EN (1 << 15)
> > +#define SDRAM_PCR_MREQI_DIS (1 << 17)
> > +
> > +/* Fixed priority DRAM Requests mask */
> > +#define SDRAM_REQ_VGA_HW_CURSOR (1 << 0)
> > +#define SDRAM_REQ_VGA_TEXT_CG_FONT (1 << 1)
> > +#define SDRAM_REQ_VGA_TEXT_ASCII (1 << 2)
> > +#define SDRAM_REQ_VGA_CRT (1 << 3)
> > +#define SDRAM_REQ_SOC_DC_CURSOR (1 << 4)
> > +#define SDRAM_REQ_SOC_DC_OCD (1 << 5)
> > +#define SDRAM_REQ_SOC_DC_CRT (1 << 6)
> > +#define SDRAM_REQ_VIDEO_HIPRI_WRITE (1 << 7)
> > +#define SDRAM_REQ_USB20_EHCI1 (1 << 8)
> > +#define SDRAM_REQ_USB20_EHCI2 (1 << 9)
> > +#define SDRAM_REQ_CPU (1 << 10)
> > +#define SDRAM_REQ_AHB2 (1 << 11)
> > +#define SDRAM_REQ_AHB (1 << 12)
> > +#define SDRAM_REQ_MAC0 (1 << 13)
> > +#define SDRAM_REQ_MAC1 (1 << 14)
> > +#define SDRAM_REQ_PCIE (1 << 16)
> > +#define SDRAM_REQ_XDMA (1 << 17)
> > +#define SDRAM_REQ_ENCRYPTION (1 << 18)
> > +#define SDRAM_REQ_VIDEO_FLAG (1 << 21)
> > +#define SDRAM_REQ_VIDEO_LOW_PRI_WRITE (1 << 28)
> > +#define SDRAM_REQ_2D_RW (1 << 29)
> > +#define SDRAM_REQ_MEMCHECK (1 << 30)
> > +
> > +#define SDRAM_ICR_RESET_ALL (1 << 31)
> > +
> > +#define SDRAM_CONF_CAP_SHIFT 0
> > +#define SDRAM_CONF_CAP_MASK 3
> > +#define SDRAM_CONF_DDR4 (1 << 4)
> > +#define SDRAM_CONF_SCRAMBLE (1 << 8)
> > +#define SDRAM_CONF_SCRAMBLE_PAT2 (1 << 9)
> > +#define SDRAM_CONF_CACHE_EN (1 << 10)
> > +#define SDRAM_CONF_CACHE_INIT_EN (1 << 12)
> > +#define SDRAM_CONF_DUALX8 (1 << 13)
> > +#define SDRAM_CONF_CACHE_INIT_DONE (1 << 19)
> > +
> > +#define SDRAM_CONF_CAP_128M 0
> > +#define SDRAM_CONF_CAP_256M 1
> > +#define SDRAM_CONF_CAP_512M 2
> > +#define SDRAM_CONF_CAP_1024M 3
> > +
> > +#define SDRAM_MISC_DDR4_TREFRESH (1 << 3)
> > +
> > +#define SDRAM_PHYCTRL0_INIT (1 << 0)
> > +#define SDRAM_PHYCTRL0_AUTO_UPDATE (1 << 1)
> > +#define SDRAM_PHYCTRL0_NRST (1 << 2)
> > +
> > +#define SDRAM_REFRESH_CYCLES_SHIFT 0
> > +#define SDRAM_REFRESH_CYCLES_MASK 0xf
> > +#define SDRAM_REFRESH_ZQCS_EN (1 << 7)
> > +#define SDRAM_REFRESH_PERIOD_SHIFT 8
> > +#define SDRAM_REFRESH_PERIOD_MASK 0xf
> > +
> > +#define SDRAM_TEST_LEN_SHIFT 4
> > +#define SDRAM_TEST_LEN_MASK 0xfffff
> > +#define SDRAM_TEST_START_ADDR_SHIFT 24
> > +#define SDRAM_TEST_START_ADDR_MASK 0x3f
> > +
> > +#define SDRAM_TEST_EN (1 << 0)
> > +#define SDRAM_TEST_MODE_SHIFT 1
> > +#define SDRAM_TEST_MODE_MASK 3
> > +#define SDRAM_TEST_MODE_WO 0
> > +#define SDRAM_TEST_MODE_RB 1
> > +#define SDRAM_TEST_MODE_RW 2
> > +#define SDRAM_TEST_GEN_MODE_SHIFT 3
> > +#define SDRAM_TEST_GEN_MODE_MASK 7
> > +#define SDRAM_TEST_TWO_MODES (1 << 6)
> > +#define SDRAM_TEST_ERRSTOP (1 << 7)
> > +#define SDRAM_TEST_DONE (1 << 12)
> > +#define SDRAM_TEST_FAIL (1 << 13)
> > +
> > +#define SDRAM_AC_TRFC_SHIFT 0
> > +#define SDRAM_AC_TRFC_MASK 0xff
> > +
> > +#ifndef __ASSEMBLY__
> > +
> > +struct ast2500_sdrammc_regs {
> > + u32 protection_key;
> > + u32 config;
> > + u32 gm_protection_key;
> > + u32 refresh_timing;
> > + u32 ac_timing[3];
> > + u32 misc_control;
> > + u32 mr46_mode_setting;
> > + u32 mr5_mode_setting;
> > + u32 mode_setting_control;
> > + u32 mr02_mode_setting;
> > + u32 mr13_mode_setting;
> > + u32 power_control;
> > + u32 req_limit_mask;
> > + u32 pri_group_setting;
> > + u32 max_grant_len[4];
> > + u32 intr_ctrl;
> > + u32 ecc_range_ctrl;
> > + u32 first_ecc_err_addr;
> > + u32 last_ecc_err_addr;
> > + u32 phy_ctrl[4];
> > + u32 ecc_test_ctrl;
> > + u32 test_addr;
> > + u32 test_fail_dq_bit;
> > + u32 test_init_val;
> > + u32 phy_debug_ctrl;
> > + u32 phy_debug_data;
> > + u32 reserved1[30];
> > + u32 scu_passwd;
> > + u32 reserved2[7];
> > + u32 scu_mpll;
> > + u32 reserved3[19];
> > + u32 scu_hwstrap;
> > +};
> > +
> > +#endif /* __ASSEMBLY__ */
> > +
> > +#endif /* _ASM_ARCH_SDRAM_AST2500_H */
> > diff --git a/arch/arm/mach-aspeed/ast2500/Makefile
> b/arch/arm/mach-aspeed/ast2500/Makefile
> > index 97d4078ddd..a35b239ef3 100644
> > --- a/arch/arm/mach-aspeed/ast2500/Makefile
> > +++ b/arch/arm/mach-aspeed/ast2500/Makefile
> > @@ -1 +1 @@
> > -obj-y += clk_ast2500.o
> > +obj-y += clk_ast2500.o sdram_ast2500.o
> > diff --git a/arch/arm/mach-aspeed/ast2500/sdram_ast2500.c
> b/arch/arm/mach-aspeed/ast2500/sdram_ast2500.c
> > new file mode 100644
> > index 0000000000..da25756e94
> > --- /dev/null
> > +++ b/arch/arm/mach-aspeed/ast2500/sdram_ast2500.c
> > @@ -0,0 +1,443 @@
> > +/*
> > + * Copyright (C) 2012-2020 ASPEED Technology Inc.
> > + *
> > + * Copyright 2016 Google, Inc
> > + *
> > + * SPDX-License-Identifier: GPL-2.0
> > + */
> > +
> > +#include <common.h>
> > +#include <clk.h>
> > +#include <dm.h>
> > +#include <dt-bindings/clock/ast2500-scu.h>
> > +#include <errno.h>
> > +#include <ram.h>
> > +#include <asm/io.h>
> > +#include <asm/arch/scu_ast2500.h>
> > +#include <asm/arch/sdram_ast2500.h>
> > +#include <asm/arch/wdt.h>
> > +#include <linux/err.h>
> > +#include <linux/kernel.h>
> > +#include <regmap.h>
>
> Check ordering: http://www.denx.de/wiki/U-Boot/CodingStyle

Done

>
>
> > +
> > +/* These configuration parameters are taken from Aspeed SDK */
> > +#define DDR4_MR46_MODE 0x08000000
> > +#define DDR4_MR5_MODE 0x400
> > +#define DDR4_MR13_MODE 0x101
> > +#define DDR4_MR02_MODE 0x410
> > +#define DDR4_TRFC 0x45457188
> > +
> > +#define PHY_CFG_SIZE 15
> > +
> > +static const u32 ddr4_ac_timing[3] = {0x63604e37, 0xe97afa99,
> 0x00019000};
> > +static const struct {
> > + u32 index[PHY_CFG_SIZE];
> > + u32 value[PHY_CFG_SIZE];
> > +} ddr4_phy_config = {
> > + .index = {0, 1, 3, 4, 5, 56, 57, 58, 59, 60, 61, 62, 36, 49, 50},
> > + .value = {
> > + 0x42492aae, 0x09002000, 0x55e00b0b, 0x20000000, 0x24,
> > + 0x03002900, 0x0e0000a0, 0x000e001c, 0x35b8c106,
> 0x08080607,
> > + 0x9b000900, 0x0e400a00, 0x00100008, 0x3c183c3c,
> 0x00631e0e,
> > + },
> > +};
> > +
> > +#define SDRAM_MAX_SIZE (1024 * 1024 * 1024)
> > +#define SDRAM_MIN_SIZE (128 * 1024 * 1024)
> > +
> > +DECLARE_GLOBAL_DATA_PTR;
> > +
> > +/*
> > + * Bandwidth configuration parameters for different SDRAM requests.
> > + * These are hardcoded settings taken from Aspeed SDK.
> > + */
> > +static const u32 ddr_max_grant_params[4] = {
> > + 0x88448844, 0x24422288, 0x22222222, 0x22222222
> > +};
> > +
> > +/*
> > + * These registers are not documented by Aspeed at all.
> > + * All writes and reads are taken pretty much as is from SDK.
> > + */
> > +struct ast2500_ddr_phy {
> > + u32 phy[117];
> > +};
> > +
> > +struct dram_info {
> > + struct ram_info info;
> > + struct clk ddr_clk;
> > + struct ast2500_sdrammc_regs *regs;
> > + struct ast2500_scu *scu;
> > + struct ast2500_ddr_phy *phy;
> > + ulong clock_rate;
> > +};
> > +
> > +static int ast2500_sdrammc_reset(void)
> > +{
> > + struct ast_wdt *wdt = ast_get_wdt(0);
>
> blank line. But can you pass this in as a parameter?
>
> > + if (IS_ERR(wdt))
> > + return PTR_ERR(wdt);
> > +
> > + /* Only Reset SDRAM */
> > + writel(WDT_RESET_SDRAM, &wdt->reset_mask);
> > + clrbits_le32(&wdt->ctrl,
> > + WDT_CTRL_RESET_MASK << WDT_CTRL_RESET_MODE_SHIFT);
> > + wdt_start(wdt, 1);
> > +
> > + /* Wait for WDT to reset */
> > + while (readl(&wdt->ctrl) & WDT_CTRL_EN)
> > + ;
> > + wdt_stop(wdt);
>
> Feels like you should have a helper function or driver to do the
> reset, not access the watchdog here.
>

I created a helper function in ast_wdt.c

I agree that it would be best to have reset driver here, especially since I
would need it in the future,
but as I tried to implement it the change kind of snowballed. I.e. for
aspeed reset driver would need to use watchdog, but then for watchdog, as
you suggested, there also need to be a -uclass.c to make it a proper DM
driver.
I don't mind doing all of this -- feel free to hold my future changes
hostage before I do :) -- but for the sake of keeping the size of this
change under control, I would rather just use a function here.

All other comments have been addressed for v4.

>
> > +
> > + return 0;
> > +}
> > +
> > +static int ast2500_sdrammc_init_phy(struct ast2500_ddr_phy *phy)
> > +{
> > + writel(0, &phy->phy[2]);
> > + writel(0, &phy->phy[6]);
> > + writel(0, &phy->phy[8]);
> > + writel(0, &phy->phy[10]);
> > + writel(0, &phy->phy[12]);
> > + writel(0, &phy->phy[42]);
> > + writel(0, &phy->phy[44]);
> > +
> > + writel(0x86000000, &phy->phy[16]);
> > + writel(0x00008600, &phy->phy[17]);
> > + writel(0x80000000, &phy->phy[18]);
> > + writel(0x80808080, &phy->phy[19]);
> > +
> > + return 0;
> > +}
> > +
> > +static void ast2500_ddr_phy_init_process(struct dram_info *info)
> > +{
> > + struct ast2500_sdrammc_regs *regs = info->regs;
>
> blank line. Please fix globally - need a line between decls and code.
>
> > + writel(0, &regs->phy_ctrl[0]);
> > + writel(0x4040, &info->phy->phy[51]);
> > +
> > + writel(SDRAM_PHYCTRL0_NRST | SDRAM_PHYCTRL0_INIT,
> &regs->phy_ctrl[0]);
> > + while ((readl(&regs->phy_ctrl[0]) & SDRAM_PHYCTRL0_INIT))
> > + ;
> > + writel(SDRAM_PHYCTRL0_NRST | SDRAM_PHYCTRL0_AUTO_UPDATE,
> > + &regs->phy_ctrl[0]);
> > +}
> > +
> > +static void ast2500_sdrammc_set_vref(struct dram_info *info, u32 vref)
> > +{
> > + writel(0, &info->regs->phy_ctrl[0]);
> > + writel((vref << 8) | 0x6, &info->phy->phy[48]);
> > + ast2500_ddr_phy_init_process(info);
> > +}
> > +
> > +static int ast2500_ddr_cbr_test(struct dram_info *info)
> > +{
> > + struct ast2500_sdrammc_regs *regs = info->regs;
> > + int i;
> > + const u32 test_params = SDRAM_TEST_EN
> > + | SDRAM_TEST_ERRSTOP
> > + | SDRAM_TEST_TWO_MODES;
> > + int ret = 0;
> > +
> > + writel((1 << SDRAM_REFRESH_CYCLES_SHIFT) |
> > + (0x5c << SDRAM_REFRESH_PERIOD_SHIFT),
> &regs->refresh_timing);
> > + writel((0xfff << SDRAM_TEST_LEN_SHIFT), &regs->test_addr);
> > + writel(0xff00ff00, &regs->test_init_val);
> > + writel(SDRAM_TEST_EN | (SDRAM_TEST_MODE_RW <<
> SDRAM_TEST_MODE_SHIFT) |
> > + SDRAM_TEST_ERRSTOP, &regs->ecc_test_ctrl);
> > +
> > + while (!(readl(&regs->ecc_test_ctrl) & SDRAM_TEST_DONE))
> > + ;
> > +
> > + if (readl(&regs->ecc_test_ctrl) & SDRAM_TEST_FAIL) {
> > + ret = -EIO;
> > + } else {
> > + for (i = 0; i <= SDRAM_TEST_GEN_MODE_MASK; ++i) {
> > + writel((i << SDRAM_TEST_GEN_MODE_SHIFT) |
> test_params,
> > + &regs->ecc_test_ctrl);
> > + while (!(readl(&regs->ecc_test_ctrl) &
> SDRAM_TEST_DONE))
> > + ;
> > + if (readl(&regs->ecc_test_ctrl) &
> SDRAM_TEST_FAIL) {
> > + ret = -EIO;
> > + break;
> > + }
> > + }
> > + }
> > +
> > + writel(0, &regs->refresh_timing);
> > + writel(0, &regs->ecc_test_ctrl);
>
> blank line before 'return' line.
>
> > + return ret;
> > +}
> > +
> > +static int ast2500_sdrammc_ddr4_calibrate_vref(struct dram_info *info)
> > +{
> > + int i;
> > + int vref_min = 0xff;
> > + int vref_max = 0;
> > + int range_size = 0;
> > +
> > + for (i = 1; i < 0x40; ++i) {
> > + ast2500_sdrammc_set_vref(info, i);
> > +
> > + int res = ast2500_ddr_cbr_test(info);
> > + if (res < 0) {
> > + if (range_size > 0)
> > + break;
> > + } else {
> > + ++range_size;
> > + vref_min = min(vref_min, i);
> > + vref_max = max(vref_max, i);
> > + }
> > + }
> > +
> > + /* Pick average setting */
> > + ast2500_sdrammc_set_vref(info, (vref_min + vref_max + 1) / 2);
> > +
> > + return 0;
> > +}
> > +
> > +static size_t ast2500_sdrammc_get_vga_mem_size(struct dram_info *info)
> > +{
> > + size_t vga_mem_size_base = 8 * 1024 * 1024;
> > + u32 vga_hwconf = (readl(&info->scu->hwstrap)
> > + >> SCU_HWSTRAP_VGAMEM_SHIFT)
> > + & SCU_HWSTRAP_VGAMEM_MASK;
> > +
> > + return vga_mem_size_base << vga_hwconf;
> > +}
> > +
> > +/*
> > + * Find out RAM size and save it in dram_info
> > + *
> > + * The procedure is taken from Aspeed SDK
> > + */
> > +static void ast2500_sdrammc_calc_size(struct dram_info *info)
> > +{
> > + /* The controller supports 128/256/512/1024 MB ram */
> > + size_t ram_size = SDRAM_MIN_SIZE;
> > + const int write_test_offset = 0x100000;
> > + u32 test_pattern = 0xdeadbeef;
> > + u32 cap_param = SDRAM_CONF_CAP_1024M;
> > + u32 refresh_timing_param = DDR4_TRFC;
> > + const u32 write_addr_base = CONFIG_SYS_SDRAM_BASE +
> write_test_offset;
> > +
> > + for (ram_size = SDRAM_MAX_SIZE; ram_size > SDRAM_MIN_SIZE;
> > + ram_size >>= 1) {
> > + writel(test_pattern, write_addr_base + (ram_size >> 1));
> > + test_pattern = (test_pattern >> 4) | (test_pattern <<
> 28);
> > + }
> > +
> > + /* One last write to overwrite all wrapped values */
> > + writel(test_pattern, write_addr_base);
> > +
> > + /* Reset the pattern and see which value was really written */
> > + test_pattern = 0xdeadbeef;
> > + for (ram_size = SDRAM_MAX_SIZE; ram_size > SDRAM_MIN_SIZE;
> > + ram_size >>= 1) {
> > + if (readl(write_addr_base + (ram_size >> 1)) ==
> test_pattern)
> > + break;
> > +
> > + --cap_param;
> > + refresh_timing_param >>= 8;
> > + test_pattern = (test_pattern >> 4) | (test_pattern <<
> 28);
> > + }
> > +
> > + clrsetbits_le32(&info->regs->ac_timing[1],
> > + (SDRAM_AC_TRFC_MASK << SDRAM_AC_TRFC_SHIFT),
> > + ((refresh_timing_param & SDRAM_AC_TRFC_MASK)
> > + << SDRAM_AC_TRFC_SHIFT));
> > +
> > + info->info.base = CONFIG_SYS_SDRAM_BASE;
> > + info->info.size = ram_size - ast2500_sdrammc_get_vga_mem_
> size(info);
> > + clrsetbits_le32(&info->regs->config,
> > + (SDRAM_CONF_CAP_MASK << SDRAM_CONF_CAP_SHIFT),
> > + ((cap_param & SDRAM_CONF_CAP_MASK)
> > + << SDRAM_CONF_CAP_SHIFT));
> > +}
> > +
> > +static int ast2500_sdrammc_init_ddr4(struct dram_info *info)
> > +{
> > + int i;
> > + const u32 power_control = SDRAM_PCR_CKE_EN
> > + | (1 << SDRAM_PCR_CKE_DELAY_SHIFT)
> > + | (2 << SDRAM_PCR_TCKE_PW_SHIFT)
> > + | SDRAM_PCR_RESETN_DIS
> > + | SDRAM_PCR_RGAP_CTRL_EN | SDRAM_PCR_ODT_EN |
> SDRAM_PCR_ODT_EXT_EN;
> > + const u32 conf = (SDRAM_CONF_CAP_1024M << SDRAM_CONF_CAP_SHIFT)
> > +#ifdef CONFIG_DUALX8_RAM
> > + | SDRAM_CONF_DUALX8
> > +#endif
> > + | SDRAM_CONF_SCRAMBLE | SDRAM_CONF_SCRAMBLE_PAT2 |
> SDRAM_CONF_DDR4;
> > +
> > + writel(conf, &info->regs->config);
> > + for (i = 0; i < ARRAY_SIZE(ddr4_ac_timing); ++i)
> > + writel(ddr4_ac_timing[i], &info->regs->ac_timing[i]);
> > +
> > + writel(DDR4_MR46_MODE, &info->regs->mr46_mode_setting);
> > + writel(DDR4_MR5_MODE, &info->regs->mr5_mode_setting);
> > + writel(DDR4_MR02_MODE, &info->regs->mr02_mode_setting);
> > + writel(DDR4_MR13_MODE, &info->regs->mr13_mode_setting);
> > +
> > + for (i = 0; i < PHY_CFG_SIZE; ++i) {
> > + writel(ddr4_phy_config.value[i],
> > + &info->phy->phy[ddr4_phy_config.index[i]]);
> > + }
> > +
> > + writel(power_control, &info->regs->power_control);
> > +
> > + ast2500_ddr_phy_init_process(info);
> > +
> > + int ret = ast2500_sdrammc_ddr4_calibrate_vref(info);
>
> please declare variables at the top of functions if you can, or inside
> the block that needs them.
>
> > + if (ret < 0) {
> > + debug("Vref calibration failed!\n");
> > + return ret;
> > + }
> > +
> > + writel((1 << SDRAM_REFRESH_CYCLES_SHIFT)
> > + | SDRAM_REFRESH_ZQCS_EN | (0x2f <<
> SDRAM_REFRESH_PERIOD_SHIFT),
> > + &info->regs->refresh_timing);
> > +
> > + setbits_le32(&info->regs->power_control,
> > + SDRAM_PCR_AUTOPWRDN_EN | SDRAM_PCR_ODT_AUTO_ON);
> > +
> > + ast2500_sdrammc_calc_size(info);
> > +
> > + setbits_le32(&info->regs->config, SDRAM_CONF_CACHE_INIT_EN);
> > + while (!(readl(&info->regs->config) &
> SDRAM_CONF_CACHE_INIT_DONE))
> > + ;
> > + setbits_le32(&info->regs->config, SDRAM_CONF_CACHE_EN);
> > +
> > + writel(SDRAM_MISC_DDR4_TREFRESH, &info->regs->misc_control);
> > +
> > + /* Enable all requests except video & display */
> > + writel(SDRAM_REQ_USB20_EHCI1
> > + | SDRAM_REQ_USB20_EHCI2
> > + | SDRAM_REQ_CPU
> > + | SDRAM_REQ_AHB2
> > + | SDRAM_REQ_AHB
> > + | SDRAM_REQ_MAC0
> > + | SDRAM_REQ_MAC1
> > + | SDRAM_REQ_PCIE
> > + | SDRAM_REQ_XDMA
> > + | SDRAM_REQ_ENCRYPTION
> > + | SDRAM_REQ_VIDEO_FLAG
> > + | SDRAM_REQ_VIDEO_LOW_PRI_WRITE
> > + | SDRAM_REQ_2D_RW
> > + | SDRAM_REQ_MEMCHECK, &info->regs->req_limit_mask);
> > +
> > + return 0;
> > +}
> > +
> > +static void ast2500_sdrammc_unlock(struct dram_info *info)
> > +{
> > + writel(SDRAM_UNLOCK_KEY, &info->regs->protection_key);
> > + while (!readl(&info->regs->protection_key))
> > + ;
> > +}
> > +
> > +static void ast2500_sdrammc_lock(struct dram_info *info)
> > +{
> > + writel(~SDRAM_UNLOCK_KEY, &info->regs->protection_key);
> > + while (readl(&info->regs->protection_key))
> > + ;
> > +}
> > +
> > +static int ast2500_sdrammc_probe(struct udevice *dev)
> > +{
> > + struct dram_info *priv = (struct dram_info *)dev_get_priv(dev);
> > + struct ast2500_sdrammc_regs *regs = priv->regs;
> > + int ret = clk_get_by_index(dev, 0, &priv->ddr_clk);
>
> Move this assignment to just before your 'if' below.
>
> > + int i;
> > +
> > + if (ret) {
> > + debug("DDR:No CLK\n");
> > + return ret;
> > + }
> > +
> > + priv->scu = ast_get_scu();
> > + if (IS_ERR(priv->scu))
>
> debug()
>
> > + return PTR_ERR(priv->scu);
> > +
> > + clk_set_rate(&priv->ddr_clk, priv->clock_rate);
> > + ret = ast2500_sdrammc_reset();
> > + if (ret)
>
> debug()
>
> > + return ret;
> > +
> > + ast2500_sdrammc_unlock(priv);
> > +
> > + writel(SDRAM_PCR_MREQI_DIS | SDRAM_PCR_RESETN_DIS,
> > + &regs->power_control);
> > + writel(SDRAM_VIDEO_UNLOCK_KEY, &regs->gm_protection_key);
> > +
> > + /* Mask all requests except CPU and AHB during PHY init */
> > + writel(~(SDRAM_REQ_CPU | SDRAM_REQ_AHB), &regs->req_limit_mask);
> > +
> > + for (i = 0; i < ARRAY_SIZE(ddr_max_grant_params); ++i)
> > + writel(ddr_max_grant_params[i],
> &regs->max_grant_len[i]);
> > +
> > + setbits_le32(&regs->intr_ctrl, SDRAM_ICR_RESET_ALL);
> > +
> > + ast2500_sdrammc_init_phy(priv->phy);
> > + if (readl(&priv->scu->hwstrap) & SCU_HWSTRAP_DDR4) {
> > + ast2500_sdrammc_init_ddr4(priv);
> > + } else {
> > + debug("Unsupported DRAM3\n");
> > + return -EINVAL;
> > + }
> > +
> > + clrbits_le32(&regs->intr_ctrl, SDRAM_ICR_RESET_ALL);
> > + ast2500_sdrammc_lock(priv);
> > +
> > + return 0;
> > +}
> > +
> > +static int ast2500_sdrammc_ofdata_to_platdata(struct udevice *dev)
> > +{
> > + struct dram_info *priv = dev_get_priv(dev);
> > + struct regmap *map;
> > + int ret = regmap_init_mem(dev, &map);
> > +
>
> Move assignment or ret to here.
>
> > + if (ret)
> > + return ret;
> > +
> > + priv->regs = regmap_get_range(map, 0);
> > + priv->phy = regmap_get_range(map, 1);
> > +
> > + priv->clock_rate = fdtdec_get_int(gd->fdt_blob, dev->of_offset,
> > + "clock-frequency", 0);
> > +
> > + if (!priv->clock_rate) {
> > + debug("DDR Clock Rate not defined\n");
> > + return -EINVAL;
> > + }
> > +
> > + return 0;
> > +}
> > +
> > +static int ast2500_sdrammc_get_info(struct udevice *dev, struct
> ram_info *info)
> > +{
> > + struct dram_info *priv = dev_get_priv(dev);
> > +
> > + *info = priv->info;
> > +
> > + return 0;
> > +}
> > +
> > +static struct ram_ops ast2500_sdrammc_ops = {
> > + .get_info = ast2500_sdrammc_get_info,
> > +};
> > +
> > +static const struct udevice_id ast2500_sdrammc_ids[] = {
> > + { .compatible = "aspeed,ast2500-sdrammc" },
> > + { }
> > +};
> > +
> > +U_BOOT_DRIVER(sdrammc_ast2500) = {
> > + .name = "aspeed_ast2500_sdrammc",
> > + .id = UCLASS_RAM,
> > + .of_match = ast2500_sdrammc_ids,
> > + .ops = &ast2500_sdrammc_ops,
> > + .ofdata_to_platdata = ast2500_sdrammc_ofdata_to_platdata,
> > + .probe = ast2500_sdrammc_probe,
> > + .priv_auto_alloc_size = sizeof(struct dram_info),
> > +};
> > --
> > 2.11.0.390.gc69c2f50cf-goog
> >
>
> Regards,
> Simon
>

--
*M*axim *S*loyko