drivers: ddr: Add DDR2 SDRAM controller driver for Microchip PIC32.
This driver initializes PIC32 DDR2 SDRAM controller and internal DDR2 Phy module.
DDR2 controller operates in half-rate mode (upto 533MHZ frequency).
Signed-off-by: Paul Thacker <paul.thacker@microchip.com>
Signed-off-by: Purna Chandra Mandal <purna.mandal@microchip.com>
Reviewed-by: Daniel Schwierzeck <daniel.schwierzeck@gmail.com>
Reviewed-by: Tom Rini <trini@konsulko.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
diff --git a/drivers/ddr/microchip/ddr2.c b/drivers/ddr/microchip/ddr2.c
new file mode 100644
index 0000000..6056418
--- /dev/null
+++ b/drivers/ddr/microchip/ddr2.c
@@ -0,0 +1,278 @@
+/*
+ * (c) 2015 Paul Thacker <paul.thacker@microchip.com>
+ *
+ * SPDX-License-Identifier: GPL-2.0+
+ *
+ */
+#include <common.h>
+#include <wait_bit.h>
+#include <linux/kernel.h>
+#include <linux/bitops.h>
+#include <mach/pic32.h>
+#include <mach/ddr.h>
+
+#include "ddr2_regs.h"
+#include "ddr2_timing.h"
+
+/* init DDR2 Phy */
+void ddr2_phy_init(void)
+{
+ struct ddr2_phy_regs *ddr2_phy;
+ u32 pad_ctl;
+
+ ddr2_phy = ioremap(PIC32_DDR2P_BASE, sizeof(*ddr2_phy));
+
+ /* PHY_DLL_RECALIB */
+ writel(DELAY_START_VAL(3) | DISABLE_RECALIB(0) |
+ RECALIB_CNT(0x10), &ddr2_phy->dll_recalib);
+
+ /* PHY_PAD_CTRL */
+ pad_ctl = ODT_SEL | ODT_EN | DRIVE_SEL(0) |
+ ODT_PULLDOWN(2) | ODT_PULLUP(3) |
+ EXTRA_OEN_CLK(0) | NOEXT_DLL |
+ DLR_DFT_WRCMD | HALF_RATE |
+ DRVSTR_PFET(0xe) | DRVSTR_NFET(0xe) |
+ RCVR_EN | PREAMBLE_DLY(2);
+ writel(pad_ctl, &ddr2_phy->pad_ctrl);
+
+ /* SCL_CONFIG_0 */
+ writel(SCL_BURST8 | SCL_DDR_CONNECTED | SCL_RCAS_LAT(RL) |
+ SCL_ODTCSWW, &ddr2_phy->scl_config_1);
+
+ /* SCL_CONFIG_1 */
+ writel(SCL_CSEN | SCL_WCAS_LAT(WL), &ddr2_phy->scl_config_2);
+
+ /* SCL_LAT */
+ writel(SCL_CAPCLKDLY(3) | SCL_DDRCLKDLY(4), &ddr2_phy->scl_latency);
+}
+
+/* start phy self calibration logic */
+static int ddr2_phy_calib_start(void)
+{
+ struct ddr2_phy_regs *ddr2_phy;
+
+ ddr2_phy = ioremap(PIC32_DDR2P_BASE, sizeof(*ddr2_phy));
+
+ /* DDR Phy SCL Start */
+ writel(SCL_START | SCL_EN, &ddr2_phy->scl_start);
+
+ /* Wait for SCL for data byte to pass */
+ return wait_for_bit(__func__, &ddr2_phy->scl_start, SCL_LUBPASS,
+ true, CONFIG_SYS_HZ, false);
+}
+
+/* DDR2 Controller initialization */
+
+/* Target Agent Arbiter */
+static void ddr_set_arbiter(struct ddr2_ctrl_regs *ctrl,
+ const struct ddr2_arbiter_params *const param)
+{
+ int i;
+
+ for (i = 0; i < NUM_AGENTS; i++) {
+ /* set min burst size */
+ writel(i * MIN_LIM_WIDTH, &ctrl->tsel);
+ writel(param->min_limit, &ctrl->minlim);
+
+ /* set request period (4 * req_period clocks) */
+ writel(i * RQST_PERIOD_WIDTH, &ctrl->tsel);
+ writel(param->req_period, &ctrl->reqprd);
+
+ /* set number of burst accepted */
+ writel(i * MIN_CMDACPT_WIDTH, &ctrl->tsel);
+ writel(param->min_cmd_acpt, &ctrl->mincmd);
+ }
+}
+
+const struct ddr2_arbiter_params *__weak board_get_ddr_arbiter_params(void)
+{
+ /* default arbiter parameters */
+ static const struct ddr2_arbiter_params arb_params[] = {
+ { .min_limit = 0x1f, .req_period = 0xff, .min_cmd_acpt = 0x04,},
+ { .min_limit = 0x1f, .req_period = 0xff, .min_cmd_acpt = 0x10,},
+ { .min_limit = 0x1f, .req_period = 0xff, .min_cmd_acpt = 0x10,},
+ { .min_limit = 0x04, .req_period = 0xff, .min_cmd_acpt = 0x04,},
+ { .min_limit = 0x04, .req_period = 0xff, .min_cmd_acpt = 0x04,},
+ };
+
+ return &arb_params[0];
+}
+
+static void host_load_cmd(struct ddr2_ctrl_regs *ctrl, u32 cmd_idx,
+ u32 hostcmd2, u32 hostcmd1, u32 delay)
+{
+ u32 hc_delay;
+
+ hc_delay = max_t(u32, DIV_ROUND_UP(delay, T_CK), 2) - 2;
+ writel(hostcmd1, &ctrl->cmd10[cmd_idx]);
+ writel((hostcmd2 & 0x7ff) | (hc_delay << 11), &ctrl->cmd20[cmd_idx]);
+}
+
+/* init DDR2 Controller */
+void ddr2_ctrl_init(void)
+{
+ u32 wr2prech, rd2prech, wr2rd, wr2rd_cs;
+ u32 ras2ras, ras2cas, prech2ras, temp;
+ const struct ddr2_arbiter_params *arb_params;
+ struct ddr2_ctrl_regs *ctrl;
+
+ ctrl = ioremap(PIC32_DDR2C_BASE, sizeof(*ctrl));
+
+ /* PIC32 DDR2 controller always work in HALF_RATE */
+ writel(HALF_RATE_MODE, &ctrl->memwidth);
+
+ /* Set arbiter configuration per target */
+ arb_params = board_get_ddr_arbiter_params();
+ ddr_set_arbiter(ctrl, arb_params);
+
+ /* Address Configuration, model {CS, ROW, BA, COL} */
+ writel((ROW_ADDR_RSHIFT | (BA_RSHFT << 8) | (CS_ADDR_RSHIFT << 16) |
+ (COL_HI_RSHFT << 24) | (SB_PRI << 29) |
+ (EN_AUTO_PRECH << 30)), &ctrl->memcfg0);
+
+ writel(ROW_ADDR_MASK, &ctrl->memcfg1);
+ writel(COL_HI_MASK, &ctrl->memcfg2);
+ writel(COL_LO_MASK, &ctrl->memcfg3);
+ writel(BA_MASK | (CS_ADDR_MASK << 8), &ctrl->memcfg4);
+
+ /* Refresh Config */
+ writel(REFCNT_CLK(DIV_ROUND_UP(T_RFI, T_CK_CTRL) - 2) |
+ REFDLY_CLK(DIV_ROUND_UP(T_RFC_MIN, T_CK_CTRL) - 2) |
+ MAX_PEND_REF(7),
+ &ctrl->refcfg);
+
+ /* Power Config */
+ writel(ECC_EN(0) | ERR_CORR_EN(0) | EN_AUTO_PWR_DN(0) |
+ EN_AUTO_SELF_REF(3) | PWR_DN_DLY(8) |
+ SELF_REF_DLY(17) | PRECH_PWR_DN_ONLY(0),
+ &ctrl->pwrcfg);
+
+ /* Delay Config */
+ wr2rd = max_t(u32, DIV_ROUND_UP(T_WTR, T_CK_CTRL),
+ DIV_ROUND_UP(T_WTR_TCK, 2)) + WL + BL;
+ wr2rd_cs = max_t(u32, wr2rd - 1, 3);
+ wr2prech = DIV_ROUND_UP(T_WR, T_CK_CTRL) + WL + BL;
+ rd2prech = max_t(u32, DIV_ROUND_UP(T_RTP, T_CK_CTRL),
+ DIV_ROUND_UP(T_RTP_TCK, 2)) + BL - 2;
+ ras2ras = max_t(u32, DIV_ROUND_UP(T_RRD, T_CK_CTRL),
+ DIV_ROUND_UP(T_RRD_TCK, 2)) - 1;
+ ras2cas = DIV_ROUND_UP(T_RCD, T_CK_CTRL) - 1;
+ prech2ras = DIV_ROUND_UP(T_RP, T_CK_CTRL) - 1;
+
+ writel(((wr2rd & 0x0f) |
+ ((wr2rd_cs & 0x0f) << 4) |
+ ((BL - 1) << 8) |
+ (BL << 12) |
+ ((BL - 1) << 16) |
+ ((BL - 1) << 20) |
+ ((BL + 2) << 24) |
+ ((RL - WL + 3) << 28)), &ctrl->dlycfg0);
+
+ writel(((T_CKE_TCK - 1) |
+ (((DIV_ROUND_UP(T_DLLK, 2) - 2) & 0xff) << 8) |
+ ((T_CKE_TCK - 1) << 16) |
+ ((max_t(u32, T_XP_TCK, T_CKE_TCK) - 1) << 20) |
+ ((wr2prech >> 4) << 26) |
+ ((wr2rd >> 4) << 27) |
+ ((wr2rd_cs >> 4) << 28) |
+ (((RL + 5) >> 4) << 29) |
+ ((DIV_ROUND_UP(T_DLLK, 2) >> 8) << 30)), &ctrl->dlycfg1);
+
+ writel((DIV_ROUND_UP(T_RP, T_CK_CTRL) |
+ (rd2prech << 8) |
+ ((wr2prech & 0x0f) << 12) |
+ (ras2ras << 16) |
+ (ras2cas << 20) |
+ (prech2ras << 24) |
+ ((RL + 3) << 28)), &ctrl->dlycfg2);
+
+ writel(((DIV_ROUND_UP(T_RAS_MIN, T_CK_CTRL) - 1) |
+ ((DIV_ROUND_UP(T_RC, T_CK_CTRL) - 1) << 8) |
+ ((DIV_ROUND_UP(T_FAW, T_CK_CTRL) - 1) << 16)),
+ &ctrl->dlycfg3);
+
+ /* ODT Config */
+ writel(0x0, &ctrl->odtcfg);
+ writel(BIT(16), &ctrl->odtencfg);
+ writel(ODTRDLY(RL - 3) | ODTWDLY(WL - 3) | ODTRLEN(2) | ODTWLEN(3),
+ &ctrl->odtcfg);
+
+ /* Transfer Configuration */
+ writel(NXTDATRQDLY(2) | NXDATAVDLY(4) | RDATENDLY(2) |
+ MAX_BURST(3) | (7 << 28) | BIG_ENDIAN(0),
+ &ctrl->xfercfg);
+
+ /* DRAM Initialization */
+ /* CKE high after reset and wait 400 nsec */
+ host_load_cmd(ctrl, 0, 0, IDLE_NOP, 400000);
+
+ /* issue precharge all command */
+ host_load_cmd(ctrl, 1, 0x04, PRECH_ALL_CMD, T_RP + T_CK);
+
+ /* initialize EMR2 */
+ host_load_cmd(ctrl, 2, 0x200, LOAD_MODE_CMD, T_MRD_TCK * T_CK);
+
+ /* initialize EMR3 */
+ host_load_cmd(ctrl, 3, 0x300, LOAD_MODE_CMD, T_MRD_TCK * T_CK);
+
+ /*
+ * RDQS disable, DQSB enable, OCD exit, 150 ohm termination,
+ * AL=0, DLL enable
+ */
+ host_load_cmd(ctrl, 4, 0x100,
+ LOAD_MODE_CMD | (0x40 << 24), T_MRD_TCK * T_CK);
+ /*
+ * PD fast exit, WR REC = T_WR in clocks -1,
+ * DLL reset, CAS = RL, burst = 4
+ */
+ temp = ((DIV_ROUND_UP(T_WR, T_CK) - 1) << 1) | 1;
+ host_load_cmd(ctrl, 5, temp, LOAD_MODE_CMD | (RL << 28) | (2 << 24),
+ T_MRD_TCK * T_CK);
+
+ /* issue precharge all command */
+ host_load_cmd(ctrl, 6, 4, PRECH_ALL_CMD, T_RP + T_CK);
+
+ /* issue refresh command */
+ host_load_cmd(ctrl, 7, 0, REF_CMD, T_RFC_MIN);
+
+ /* issue refresh command */
+ host_load_cmd(ctrl, 8, 0, REF_CMD, T_RFC_MIN);
+
+ /* Mode register programming as before without DLL reset */
+ host_load_cmd(ctrl, 9, temp, LOAD_MODE_CMD | (RL << 28) | (3 << 24),
+ T_MRD_TCK * T_CK);
+
+ /* extended mode register same as before with OCD default */
+ host_load_cmd(ctrl, 10, 0x103, LOAD_MODE_CMD | (0xc << 24),
+ T_MRD_TCK * T_CK);
+
+ /* extended mode register same as before with OCD exit */
+ host_load_cmd(ctrl, 11, 0x100, LOAD_MODE_CMD | (0x4 << 28),
+ 140 * T_CK);
+
+ writel(CMD_VALID | NUMHOSTCMD(11), &ctrl->cmdissue);
+
+ /* start memory initialization */
+ writel(INIT_START, &ctrl->memcon);
+
+ /* wait for all host cmds to be transmitted */
+ wait_for_bit(__func__, &ctrl->cmdissue, CMD_VALID, false,
+ CONFIG_SYS_HZ, false);
+
+ /* inform all cmds issued, ready for normal operation */
+ writel(INIT_START | INIT_DONE, &ctrl->memcon);
+
+ /* perform phy caliberation */
+ if (ddr2_phy_calib_start())
+ printf("ddr2: phy calib failed\n");
+}
+
+phys_size_t ddr2_calculate_size(void)
+{
+ u32 temp;
+
+ temp = 1 << (COL_BITS + BA_BITS + ROW_BITS);
+ /* 16-bit data width between controller and DIMM */
+ temp = temp * CS_BITS * (16 / 8);
+ return (phys_size_t)temp;
+}